OsTrax User Guide

Introduction

Hearing the sound of a spacecraft signal or seeing the signal rising on a visual display is one of the more exciting forms of radio communication.
Receiving data from a spacecraft or making a two-way contact through a spacecraft is even more exciting.

Satelite communication is different from other forms of radio communication in that multiple actions are required to make communication possible.
Although different, satellite communication should not be difficult.

OsTrax is an exciting and innovative satellite tracking system designed to reduce the effort necessary to make and maintain satellite contacts.

OsTrax eliminates the time and effort required to maintain satellite tracking and communication information, improving focus on making more and better satellite contacts or collecting satellite telemetry data.

OsTrax is designed around three major principals; Information, Operation and Communication.

Information means that no additional resources such as a mobile app to determine future satellite passes are required. OsTrax provides satellite information based on user selection and full satellite information including communication link definitions are readily accessible. Satellite information is maintained and automatically updated without user intervention.

Operation is simplified with well placed and accessible controls to manage satellite passes, radios and rotors and monitor current status information in all areas.

Communication is end result of adequate and timely information combined with accessible and simple operation. No time lost chasing definitions or forgetting upcoming satellite passes results in more and better communicaion opportunities.

Utilizing the latest Human Performance Principals, OsTrax groups and locates relevant information where it is easily accessable, using color and highlighting to emphasis status and conditions. Controls are co-located with information to form managable information groups. The result is a system that is consistant, easy to operate and understandable at a glance, resulting in effective satellite communication.

Designed for operating ease and flexibility, OsTrax is the complete satellite tracking platform for Windows (10 and 11), Apple macOS (A64 and x64) and Ubuntu (Intel x64).

OsTrax is flexible and easily configurable using a menu system allowing extensive user customization.

OsTrax supports satellite radios with full doppler and frequency control. Multiple radio support extends the ability to use radios that do not have full satellite capability.

OsTrax supports all popular rotor controllers with full user selection of operating and range capabilities including flip mode.

Unlimited ground stations may be defined with each ground station having unlimited satellite groups.

Satellite groups allow easy arrangment of satellites in combinations like FM, telemetry or Field Day. Satellite groups are easily maintained and selectable for use.

Satellite passes are user selectable and schedulable. The Upcoming Pass feature highlights future passes for the active satellite group and highlights potential pass conflicts. Pass conflicts and/or pass priorities can be resolved using simple mouse click selections.

Satellite communication link information is automatically maintained requiring no manual interaction.

Automatic notification of Orbital Element and Satellite Profile changes results in more operating time with consistent satellite orbital and communication information.

User satellite and satellite communication link definitions support new satellites or extend satellite communication capabilities.

Contact logging creates log records that are instant, accurate and can be exported to any external logging program.

User settings, preferences and definitions can be saved to an external file for backup and recovery or to transfer a configuration to another OsTrax instance.

OsTrax Features

• Multiple operating systems: Window, macOS and Ubuntu (Intel X64), each licensed separately.
• Convenient, easy setup using pull down menus.
• Preference settings enable user optimization including pass, map, radio, rotor and doppler settings.
• Ability to run multiple concurrent instances, each separately configured.
• Message area provides system, satellite pass and orbital element update conditions.
• All popular radios including SDR.
• All popular rotor controllers supported.
• Multiple defined radios.
• Radios and rotor selectable at any time including ability to connect and disconnect from OsTrax.
• Radio and rotor interface by serial port emulation using USB with current status information.
• Orbital Element source selection with update status and user scheduled updates.
• Scheduled satellite profile updates with update status and user scheduled updates.
• User defined Satellites.
• Used defined satellite profiles.
• Unlimited ground station definitions.
• Unlimited satellite groups for each ground station.
• Simple satellite selection.
• Ability to auto schedule or skip satellite passes.
• Pass Predict, prediction of upcoming satellite passes.
• Pass selection priority.
• Detailed radio, satellite, doppler shift and rotor information.
• Satellite ground coverage footprints centered on satellite or ground station (NASA style).
• Unlimited footprints for common pass coverage determination.
• Unlimited transverters assigned to satellite communication links by name.
• Sun and Moon tracking with current position information.
• User controlled satellite pass tracking to review or preview satellite passes.
• Simple, uncluttered coverage map centered on ground station or coordinates.
• Coverage map uses colors to highlight satellite path and current pass status.
• Alternate color selections and visual icons for color impaired vision.
• Selectable future satellite pass information with path preview on coverage map.
• Satellite pass communication link selectable even with pass active.
• Satellite communication links listed and selectable by type, mode and frequency.
• Satellite doppler shift and frequencies at satellite displays.
• Optional sounds for AOS, LOS, out of passband tuning and error notification.
• Contact logging with insertion of satellite information when available, including satellite name, mode and frequencies.
• Logged contacts exportable in ADIF 2 or 3 format.

Overview

Views

Top Zone

File

Export

Export user settings to an external file as backup. See Backup for details.

Import

Restore user settings from a previously exported backup file. See Backup for details.

Exit

Gracefully terminate OsTrax.

Settings

Preferences

General

General System Settings.

Units

Set display units as Metric or Imperial

Automatic Source Update

Automatically updates Orbital Element sources when required (Source changed) without requiring manual intervention.
Notification of the updates are posted in the message center.

Source Update Interval

The time in hours between checks for updated Orbital Element sources and Satellite Profiles.

Audio Level

Sets the audio sound output level.

Instance

Opens dialog to manage multiple OsTrax instances.
Define, delete or rename instances. All about OsTrax instances.

Vision

Selects alternate plotting and status colors for red-green deficient vision. Colors explains these options.

Visual Icons

Uses visual icons in addition to colors in plotting and status information fields to supplement color only indications. Refer to Colors for more details.

Map

Map Image

Selects the map background image.

Center map

Center map longitude on the current ground station longitude or entered longitude.

Map Center Longitude

If Center Map is set to Longitude, specifies the longitude in degrees as the map center longitude.

Pass Path Width

Sets the width of the map satellite pass path.

Satellite Footprint

Selects satellite ground coverage footprint centered at the satellite coordinate location following the satellite pass path or centered on the current ground station and additional footprints (NASA syle).

Footprints

Manages optional satellite footprints centered at defined locations with the footprint size determined by the satellite altitude. Satellite Footprints provides details on managing additional satellite footprints.

Day-Night Terminator

Day-Night terminator using dark-light shading.

Pass

Min Elevation

The minimum elevation in degrees a satellite pass must reach before the pass is added to the upcoming pass list.

Pass Look Ahead

The time in hours from the current time that passes will be evaluated.

Extended Pass Time

The number of minutes a pass will be extended when the “Extend Pass” control is pressed. Extended pass time is cumulative. Each press of the control extends the pass by the desired preference.

LOS Hold Time

The time in seconds a pass will be held following LOS before it is automatically removed and the tope Upcoming Pass List promoted to be teh Current Pass.

LOS Warn Time

Specifies the number of seconds prior to LOS to visually indicate the pass is approaching LOS.

AOS Prestart Time

The number of minutes prior to a pass AOS start time OsTrax will begin tracking the satellite.

Auto Pass Select

If On, each satellite pass in the Upcoming Pass list will be automatically tracked unless disabled in the individual pass entry. Auto Pass Select is useful for automatic tracking telemetry satellites.

Pass Time Format

Selects the Pass time display format as 12 or 24 hour.

Radio

Connect Radio at Startup

Attempts to open the serial port connection to any defined radios at startup.
The serial port connection for the radios is managed by the Radio control located at the bottom of screen in the control area.

Enable Radio Control At Startup

Automatically sets the radio Control button active at startup rather than requiring manual intervention.
When the Control is active, the radio frequency and mode are set when a satellite pass begins and the radio frequencies updated by dopple shift changes during the pass.

Radio Active

Determines when radios are updated with frequency changes.

Continous

Radio(s), Doppler Shift and Satellite Frequency are continuously updated based on the selected comm link of the Current Pass.

Pass Only

Default. Radio(s), Doppler Shift and Satellite Frequency are updated only during an active pass.

Passband Edge Warning

For transponder satellite communication links generates visual and audible warnings if the radio receiver is tuned out of the link passband.

Passband Edge Warning is active only when the radio Control is enabled.

Passband limit frequencies are based on the receive frequency at the satellite and include current doppler offsets. Therefore, the frequency read on the receiver when a warning is received may be different from the defined passband limits.

Rotor

Connect Rotor at Startup

Attempts to open the serial port connection to the defined rotor at startup.
The serial port connection for the rotor is managed by the Rotor control located at the bottom of screen in the control area.

Enable Rotor Control At Startup

Automatically sets the rotor Control active at startup rather than requiring manual intervention.
When the Control is active, information is passed to the rotor contoller to position the antennas.

Park Antenna On Shutdown

Selects if the antenna is to be automatically moved to the parked position when OsTrax is normally terminated.

Park Azimuth

The azimuth position in degrees to park the rotor on shutdown or by command.

Park Elevation

The elevation position in degrees to park the rotor on shutdown or by command.

Azimuth Change

During high elevation passes determines how azimuth changes are made.
Click for more information.

Rotor Azimuth Dead Band

The number of degrees before the rotor is commanded to move to a new azimuth during a pass.

Rotor Elevation Dead Band

The number of degrees before the rotor is commanded to move to a new elevation during a pass.

Doppler

Doppler rates and timing.
For CW, FM and SSB communication links the amount doppler shift must change before the doppler is updated.

Doppler Change

The change in hertz (hz) between doppler evaluations before doppler shift is updated.

Interval

The time interval in seconds determines how often the communication link is evaluated for doppler changes. Shorter time intervals consume higher computing resources.

Ground Stations
Manage ground station definitions.

Manage ground stations and select a ground station as the current ground station.
Ground stations are defined by name and geographic coordinates in Decimal Digit form (dd.dddd) using negative numbers for West or South coordinates.
Ground stations coordinates may also be entered using a ten digit Gridsquare for the location which will be converted to the appropriate latitude and longitude coordinates.

Note:  Gridsquares define an area based on the number of character pairs entered with increasing resolution as the number of pairs increase. To achieve the accuracy of a latitude/longitude entry, five Gridsquare pairs (or ten characters) must be entered..

Altitude is approximate and entered in meters. Altitude is not used at this time but may be used in the future.

Radio Selection
Select a Radio

Rotor Selection
Select a Rotor Controller

Satellite Groups
Manage satellite groups for a ground station.

Satellite Groups are named list of satellites which may be selected for pass determination, allowing satellites to be grouped together for contest, telemetry or any desired combination. An unlimited number of satellite groups each with an unlimited number of satellites can be defined for each ground station. Only one satellite group can be active at a given time.

For more information view Satellite Groups

Transverters

Assign

Manage transverter assignments for satellite communication links.

Manage

Manage transverters by adding or deleting transverter definitions.

Details on managing transverters is found at Transverters

Sources

Source Status

List and manage Orbital Element sources. Source Status

Tools

Pass Predict

Evaluate upcoming passes for a satellite. Pass Predict

User Satellite

Manage user defined Satellites.
The User Satellites dialog defines satellites that are not in the official orbital element repositories or to correct errors found in the repositories.

Satellite selection for user defined Satellites requires setting User as the Orbital Element source. Care should be taken when using multiple sources in a selection list as the search will end at the first entry found.

User Satellites are shared across all ground stations and may be deleted or modified by any ground station.

A User Satellite entry is entered by clicking the ‘New’ key on the User Satellite dialog. This will open a management dialog where Orbital Element data describing the satellite can be entered . Clicking the Add control creates a orbital element definition as a user defined satellite.

The orbital element information can be entered in one of three ways; traditional Three Line Element (TLE) with support for Alpha-5 catalog number extensions, two line Comma Separated Value (CSV) in CelesTrak form or in multi-line JSON in either AMSAT or CelesTrak form.

• A Three Line Element (TLE) is the traditional format for satellite orbit data and is being depreciated.
OsTrax supports the Alpha-5 TLS extension to the satellite catalog identifier fields.
• A two line Comma Separated Value (CSV) consist of a header line with descriptive names for each value on the second line separated by commas using the CelesTrak format. The second line consist of the data values, in correct form, corresponding to the header entries on the first line. Only one data value line can be included.
• A JSON entry is the satellite orbital data in JSON format with descriptive names and data for each element in AMSAT or CelesTrak format. A JSON entry must begin with an open bracket { and end with a close bracket } character.

Note:  When using the AMSAT JSON format, the 'AMSAT_NAME' value replaces the traditional 'OBJECT_NAME' value.
In all cases, OsTrax attempts to use the AMSAT name, if defined.

The satellite catalog number must be unique within the User Satellite definitions.

Only one orbital element entry may be entered into the input area.

User Satellites are listed in alphabetical order in the dialog, listing the satellite name and catalog number.
To delete an entry, double click on the entry listing to open a confirmation dialog where the entry may be deleted.

User Satellites are selected from the Pass Predict dialog or Upcoming Pass Select control by selecting User as a orbital element source.

User Comm

Manage user defined satellite communication links.

User Comm links are communication links manually defined by the user. Where User Satellite must be selected in the satellite selection process, user defined communication links are available for any satellite definition matching the catalog number of the user defined communication link.

This allow for corrections to Satellite Profile comm links or inclusion for satellite comm links that are not in the Satellite Profile system or for satellites defined by the user that are not in any Orbital Element source.

User communication links (Comm Links) are shared across all ground stations and may be deleted or modified by any ground station.

User communication links are managed with the User Comm Links dialog listed by satellite catalog number. New comm links are defined by clicking the New control. To delete or update a comm link entry double-click on the comm link entry to open the Update Comm Link dialog. Pressing the Delete control deletes the comm link entry.

New comm links are defined in the ‘New Comm Link’ dialog by entering the satellite name or catalog number for the designated satellite.

The 'Matching' wildcard character '*' can be entered as the last character of the satellite name to produce a list of all satellites with names starting with and matching the entered characters up to the matching wildcard character. The 'Includes' wildcard character '#' as the last character in the entered name will result in a list of all satellite names that contain the charactes up to the wildcard character.

The satellite of interest can be selected from the list.

Note:  The catalog number is not checked for a matching satellite catalog number meaning comm links can be defined prior to a satellite definition.

Selecting an entry from the Type column establishes the Comm Link type and enabled the fields applicable for the selected type. When all fields are entered correctly, the Add control is clicked to create the new comm link.

The applicable Uplink and/or Downlink mode is selectable from the mode pulldown list.

Frequencies are entered in hertz (hz). The Passband for transponder comm links is entered in hertz (hz) and for FM repeater links requiring tone access, the tone is selected from the Tone pulldown list, Zero (0) indicating no tone is required.

User defined Comm Links are highlighted using a lighter background color in communication link selection dialogs.

Tracking
Selects tracking type.

Moon

Track the Moon.

Satellite

Track selected satellites.

Sun

Track the Sun.

User

Manually view and control the plot of a selected satellite. User Satellite Tracking

Note:   Changing the tracking selection removes any settings related to the former selection.
For example, if the current tracking selection is Satellite with passes active or scheduled and the tracking target is changed then changed back to Satellite, prior settings and schedules are lost.

Log
Create and manage contact log records that can be exported as ADIF files.
See Contact Log for details.

Information Area
The information area on the right side of the top line is comprised of two sections.

Update Available

If an orbital element update or an OsTrax Satellite Respository update is available, a control with the name Update Available is displayed.
Clicking the control, starts an immediate update of the element or repository as described here.

Instance Name

If multiple OsTrax Instances are active, the Instance name is display for reference.
Click for information on how to define and use Instances.

The default Instance name is never displayed.

Left Zone

The left zone is made up of several views that describe the physical connections between a satellite pass, OsTrax and the physical devices providing communication with the satellite.

Views are disabled or enabled based on the status of the physical connection to the devices, user controls and the state of the current satellite pass.

Views

Doppler Shift

Doppler Shift is the uplink and downlink doppler shift for the current satellite pass determined by the transmit and receive frequencies and the position and speed of the satellite.

Doppler Shift is positive as the satellite approaches the ground station and negative as the satellite moves away from the ground station.

The Doppler Shift view is enabled when a satellite pass is after the AOS prestart time and prior to the pass LOS time. The presence of the Uplink and Downlink shifts are determined by the selected satellite communication link.

Satellite Frequency

Satellite Frequency is the actual uplink (receive) and downlink (transmit) frequencies at the satellite determined by the radio receive and transmit frequency settings.

Satellite Frequency is useful when a Transponder communication link is active to determine the exact satellite frequencies based on the radio receive frequency. For FM repeater links and beacon/transponder links the frequencies are the defined frequencies for the link.

The Satellite Frequency view is enabled when a satellite pass is after the AOS prestart time and prior to the pass LOS time. The presence of the Uplink and Downlink frequencies are determined by the selected satellite communication link.

Radio

The Radio view provides operating and status information on the radio or radios selected and controls to manage the radio selections.

Each radio entry list the name of the selected radio and the name and status of the physical connection to the radio.

Note:  The connection status is only the physical connection status and does not indicate communication is active with the radio. For example, a USB serial adapter will only reflect the status of the connection between OsTrax and the adapter and does not indicate the presence of a physical connection between the adapter and the radio.

Note:  If a radio is powered on after OsTrax starts, a radio is selected or a pass started, it is necesssary to recycle the radio "Control" before OsTrax can communicate with the radio.

The actual uplink (transmit) and downlink (receive) frequencies of the radio are displayed adjusted for any applicable doppler shift.

If multiple radios are selected, the top radio will be configured for transmit only with the bottom configured for receive. The uplink and downlink frequency displays will be associated with the appropriate transmit and receive radio.

The Radio view is enabled when a satellite pass is after the AOS prestart time and prior to the pass LOS time. The presence of the Uplink and Downlink frequencies are determined by the selected satellite communication link.

Controls

Set

Sets the radio or radios to the frequencies defined for the active satellite communication link. For Transponder communication links the frequency is set to the center of the transponder passband adjusted for current doppler rates.

Control

Provides control of frequency updates to the radio. When enabled, the radio or radios are updated based on the satellite doppler shift based on rates set in Setting->Preferences->Doppler for the communication link type.

If a satellite pass is active and Control is selected the uplink and downlink frequencies are displayed in white. When Control is unselected the uplink and downlink frequencies areas are disabled and the frequencies displayed in amber. The displayed frequencies continue to be updated but not passed to the radio or radios.

Radio Offsets

Radio Offsets optionally add positive or negative offsets to a transponder communication link to assist in adjusting for frequency differences in either the uplink radio and/or satellite that prevent the correct association between the radio receive frequency and the corresponding satellite downline frequency.

Offsets may be saved for the communication link and will be automatically applied to future passes.

Complete information about using offsets can be found at Radio Offsets.

Rotor

The Rotor view provides operating and status information on the selected rotor controller and controls to manage the rotor.

The Rotor view list the name of the selected controller and the name and status of the physical connection to the rotor.

Note:   The connection status is only the physical connection status and does not indicate communication is active with the rotor. For example, a USB serial adapter will only reflect the status of the connection between OsTrax and the adapter and does not indicate the presence of a physical connection between the adapter and the rotor controller.

Note:  If the rotor controller is powered on after OsTrax starts or the controller is selected, it may be necesssary to recycle the "Rotor" control before OsTrax can communicate with the rotor.

The current azimuth and elevation setting of the rotor are displayed. Azimuth and elevation are normally displayed in white unless the pass is determined to be flip capable with azimuth and elevation displayed in yellow. At the end (LOS) of a flip capable pass the azimuth and elevation settings change to white.

When a new azimuth and/or elevation is calculated for an active satellite pass, target values are displayed in green until the rotor controller reports the rotor has moved to the target setting.

Controls

Manual

Opens a dialog to allow manual rotor movement.

Manual   Moves the azimuth and elevation rotors to the selected positions.

Park   Moves the azimuth and elevation rotors to the positions defined in Settings->Preferences->Rotor.

Stop   Halts any active rotor movement.

Note:   During an active pass with Rotor Control enabled, Manual movement, Park or Stop will disable the Rotor Control and an appropriate warning status message issued.

Control

When enabled, antenna position changes during a satellite pass are sent to the rotor contoller to position the antennas.

Note:   Disabling the Rotor using the Rotor command on the bottom zone will not halt the rotor controller from completing an in-progress move.

Center Zone

The center zone is the main zone of focus containing information and map views.

At the top is the information view beginning with the current time in both local, as set by the user’s computer, and UTC updated once per second.


Following the time views is the position view showing the current azimuth, elevation and maximum elevation for an active satellite pass relative to the ground station. Position information, like the time views, is updated once per second.

Position information is only available if the current satellite pass has been started and AOS or AOS Prestart has occurred. When AOS or AOS Prestart occurs, OsTrax will begin tracking the satellite pass, updating rotor position and displaying the current azimuth and elevation for the satellite. Elevation will be highlighted in red if the current elevation is below the minimum pass elevation set in Menu-->Settings->Pass->Min Elevation. Elevation values below minimum elevation normally occur in the time period between AOS Prestart and AOS times. At AOS the elevation will be the minimum elevation.

Under the position view is the pass elevation progress bar plotted in blue which increments forward to the maximum elevation for the pass (TCA) then changes color to red and decrements downward to the LOS elevation. The elevation progress bar provides a visible indication of pass accension/descension from AOS elevation to LOS elevation.


The right position of the information view is the pass countdown clock which counts down toward the moment of AOS for a started satellite pass. The AOS countdown time is displayed in white until AOS occurs. At AOS, the text changes to LOS, displayed in green, to count down the remaining time to LOS. At the time set by the user in Settings->Preferences->Pass->LOS Warn Time, the color of the LOS countdown timer changes to red as a visible indication the end of the pass is approaching.

Once the end of the active pass is reached (LOS) the timer is disabled for the time period set by the user in Settings->Preferences->Pass->LOS Hold Time, then the current pass is deleted.

Prior to the end of the pass and during the LOS hold period the pass may be extended by clicking the Extend Pass control which extends the pass by the time period set by the user in Settings->Preferences->Pass->Extend Pass Time. When the pass is extended at the end of the active pass the countdown indicator will change to EXT highlighted in yellow and will count down to the end of the extended pass period. If the Extend pass control is again clicked the Extend Pass Time amount is added to the current count down value extending the time until the pass is deleted and the next pass made current.
As with normal LOS, when the extended time period reaches the time set in Settings->Preferences->Pass->LOS Warn Time, the color of the extended pass countdown times changes to red indicating the pending end of the extended pass.

To summarize, once the current pass has been started either by pressing the Start Pass control or the pass selected to automatically start the AOS countdown timer will begin decrementing the time to AOS then change to countdown the pass duration time to LOS. Prior to LOS depending on user settings the countdown time will change color as a visual warning of impending pass termination. The pass may be extended which will result in the countdown timer counting down the extended time period when the normal LOS time is reached.

Beneath the countdown timer, pass progress is plotted as a bar graph in blue from AOS to LOS changing to red depending on the user LOS Warn Time setting.

Map



Occupying the majority of the center zone is the map view which plots the current pass on an uncluttered world map centered either on the ground station longitude or a longitude set by Settings->Preferences->Map->Center Map. The center longitude set in Settings->Preferences->Map->Map Center Longitude.

The map is trimmed at both poles based on the width of the center view. Satellite orbit paths are adjusted when the satellite is beyond the visible map image.

Different map images can be selected at Settings->Preferences->Map->Map Image.

The current pass plot is plotted and scaled to fit the available visible area when the pass location is within one of the non-visible areas of the map.

The current pass is plotted using a simple red cubesat image to represent the current position of the satellite.

Different colors are used to indicate the state of the pass as well as the direction of the pass.

Amber

The upcoming path for the satellite.

Green

The active portion of the pass where communication is possible from the ground station.

Red

The portion of the pass the satellite has covered.

The path plot changes from yellow to red as an indication of the path direction. The active portion of the pass (AOS to LOS) is plotted with green which is replaced by red as the satellite path progresses.

The width of the path plot is set in Settings->Preferences->Map->Pass Path Width with the default set to Narrow.

The ground station location and location of any footprints are plotted based on location. If Settings->Preferences->Map->Satellite Footprint is set to Satellite the ground coverage track is plotted based on the position of the satellite. If set to NASA the satellite coverage track is plotted centered on the ground station and any active concurrent pass locations, remaining static for the duration of the pass.

If Settings->Preferences->Map->Satellite Footprint is set to Satellite the satellite footprint or ground coverage area is drawn center on the satellite.

If Settings->Preferences->Pass->Satellite Footprint is set to NASA the satellite footprint or ground coverage area is drawn centered on the ground station and as well as any Footprints defined and activated in Settings->Preferences->Map->Footprints.

Footprints provide a convenient visual indication of the possibility of communication between locations. Communication is possible in the overlapping areas.

Right Zone

The Right zone displays the current satellite pass which may be active or inactive, upcoming passes and controls to manage passes.

A Satellite Pass is a pass of a selected satellite that meets the minimum elevation requirement for the current ground station location. Minimum elevation is set in Setting->Preferences->Pass->Minimum Elevation. The pass contains information used to direct the rotor controller to track the satellite and calculate doppler shift changes affecting selected radios.

The Current Pass is the next pass available from a user selected list of satellites. The Current Pass becomes available when the previous satellite pass reaches LOS and may be some time in the future based on selected satellite and pass selections.

The Current Pass becomes active when the Start Pass control is clicked, the Auto Pass Select feature was enabled in Settings->Preferences->Pass->Auto Pass Select or the pass manually set to Schedule. Only when the pass is active will OsTrax track the satellite using the selected rotor and radio(s).

All Pass times are in local time format in 12 or 24 hour form which can be changed in Settings->Preferences->Pass->Pass Time Format.

Current Pass

The Current Pass view details pass information including static items and dynamic items that change as the pass progresses.

The satellite name is displayed at the top of the view followed by static and dynamic information.

The satellite name color indicates the pass status for the satellite.

Amber

The satellite is below the horizon approaching AOS.

Green

The satellite is above the horizon but has yet to reach AOS or has been not selected for tracking.

White

The satellite is above the horizon and is being tracked.

Pass Information

AOS

The estimated Acquisition Of Signal time as local time in 12 our 24 hour form. This is the time the satellite appears above the horizon.

LOS

The estimated Loss Of Signal time as local time in 12 or 24 hour form.

Duration

The time the satellite will be in communication range in hour-minutes-second.

MaxEl

The estimated maximum elevation the satellite will reach during the pass.

AOS Az

The approach azimuth in degrees at AOS.

LOS Az

The departing azimuth of the satellite in degrees at LOS.

Lat

The current latitude of the satellite in Decimal Degrees.

Grid

The current Gridsquare or Maiden head position of the satellite.

Height

The current height of the satellite in units set in Setting->Preferences-General.

Distance

The distance from the ground station to the satellite in units set in Setting->Preferences-General.

Speed

The current speed of the satellite in units set in Setting->Preferences-General.

Catalog

The satellite catalog number.

Eclipsed

Yes indicates the satellite is in eclipse (not illuminated by the Sun).

Orbit

The satellite orbit number for this pass.

Comm Link

The selected communication link for the satellite.
Comm Link displays the comm link type and relevant uplink and downlink frequency and mode.

FM Repeater comm links list any required uplink tone which is automatically set in the radio(s).
For Transponder comm links the uplink and downlink frequences indicate the upper and lower frequency range based on the comm link passband width.

Controls

End Pass

Ends the current pass replacing it with the next available pass. If the pass was active, tracking is halted.

Start Pass

Activates the current pass and makes the pass available for tracking. Once Start Pass is pressed or the pass Auto Pass Select started the control changes to Extend Pass.

Each click of the Extend Pass control extends the pass beyond LOS by the amount set in Settings->Preferences->Pass->Extend Pass Time and is cumulative. The pass can be extended at any point during the pass including the LOS Hold time period at the end of the pass, set in Settings->Preferences->Pass->LOS Hold Time.

Comms

Selects a Comm Link for the satellite to actively control the radios and calculate doppler shifts based on the comm link frequencies.

A Comm Link is selected by clicking the checkbox selection for the comm link and clicking ‘Select’. If the current pass is active (between AOS and LOS) the radios are switched to the comm link settings and doppler shift calculations begin based on the comm link frequencies.

If the comm links specifies frequencies not supported by the selected radios, a warning is issued and the radio controls disabled. Once a valid comm link is set, the radios can be reenabled using the ‘Radio’ control in the bottom zone.

The selection is valid only for the current pass.

Upcoming Passes



List future passes for active satellites for the time period specified in Settings->Preferences->Pass->Pass Look Ahead. Satellite to be evaluated are from the Active Satellite Group for the current ground station. The Active Satellite Group for a ground station is managed and selected with Settings->Satellite Groups.

The name of the Active Satellite Group for the ground station is listed above the pass list entries.
Pass List Entries describe upcoming satellite passes in chronological order.

Note:  Changes to individual passes as a result of changing pass options may be reset if orbital element sources are updated or if preference settings that affect pass selection are changed. Source updates and preference changes should be coordinated with pass selections.

Pass List Entry

A Pass List Entry describes an upcoming pass listing the name of the satellite, AOS and LOS times and the maximum elevation the satellite will reach.

A status area on the left uses color to indicates the relative timing of the pass as it relates to passes above it in the pass list.

Clear

The pass AOS time is beyond the LOS time of the previous list entry

Yellow

The AOS time for the entry is after the AOS time and before the LOS time of the previous entry indicating the available pass duration may be shorter than the calculated duration.

Red

The AOS time for the entry is after the AOS time of the previous entry and the LOS time for the entry is prior to the LOS time for the previous entry indicating the pass will never become active unless the previous entry is excluded as an available pass or ended once started.

If a listed pass is overlaid by the previous as described above and the listed pass has been set to automatically become active a one time information status message is issued with audio indication when the overlaid pass reaches AOS.

Further information and pass control are obtained by right or left clicking on the pass entry.

Right Click

Clicking and holding the right mouse button with the mouse on an entry will display the active path for the pass on the map until the mouse button is released.

Left Click

A left click on an entry will open the Satellite Pass dialog that will remain open until the Ok control is clicked and display the active path for the pass on the map.

Satellite Pass displays similar information as the Current Pass view and provides options to alter the pass status and change the comm link for the pass or optionally, permanently.

The Pass Options selector provides options to alter the pass status.

Manual

The pass must be manually started with the Start Pass control.

Select

Automatically starts the pass at AOS.

Exclude

Removes the pass from consideration.
Exclude can be utilized to remove a prior pass from active consideration if the following pass status area is Red indicating the full duration of the pass cannot be accomplished.

User defined communication links Menu->Settings->Sources->User Comms are highlighted for easy identification.

Controls

Active

List satellites in the current Satellite Group for the ground station by name, catalog number and Orbital Element source.
From the list, entries can be selected for permanent deletion from the satellite group or a new Satellite Groups created by selecting satellites then clicking the Create control.

Moving the mouse to a list entry and double clicking the left mouse button will display the comm links defined for the satellite.
Clicking the "Select" entry on a comm link definition then pressing the "Select" control will change the default comm link entry for the satellite.

Select

Selects satellites from selected Orbital Element sources as entries for the active ground station satellite group. Satellites are selected by satellite name or catalog number.

Multiple satellites with similar names can be selected by entering a portion of the satellite name ending with the one of two wildcard characters. Only one wildcard character can be entered.

The wildcard characters are:
*  Match wildcard.     Matches any satellite name that begins with the characters prior to the wildcard character.
#  Contains wildcard.     Matches any satellite name that contains the characters prior to the wildcard character.

If multiple satellites with similar names resulting from the wildcard search are found, they are included in the list of satellites and can be selected as satellite group members.

With no satellite name or catalog number entered, satellites can be selected from the selected Orbital Element sources using the Communication Type Selectors which will search for any satellite communication link matching at least one of the selections. Selecting satellite by communication link types can produce a lengthy result list.

If a resulting satellite entry matches a satellite currently in the active ground station satellite group, a Duplicate Selection dialog will prevent any of the listed satellites being added to the satellite group. Reselecting and eliminating the duplicate satellites is necessary.

Moving the mouse to a list entry and double clicking the left mouse button will display the comm links defined for the satellite.
Clicking the "Select" entry on a comm link definition then pressing the "Select" control will change the default comm link entry for the satellite.

Bottom Zone

The bottom zone contains operational controls and the message area where information relative to the operation status of OsTrax and relevant satellite pass information is displayed.

Controls

Radio

The Radio control enables and disables the physical connection to any attached radios.

Disabling the radios closes the physical connection to the radio halting message exchange.
Enabling the radios opens the physical connection to the radios.

Certain operations such as selecting a new radio automatically disables any open connection as the selection may change the physical connection. Error conditions with the physical connection will disable the radio connections, writing an error message to the message area.

Rotor

The Rotor control enables and disables the physical connection to any attached rotor controller.

Disabling the rotor closes the physical connection to the rotor halting message exchanges.
Enabling the rotor opens the physical connection to the rotor.

Certain operations such as selecting a new rotor controller automatically disables any open connection as the selection may change the physical connection. Error conditions with the physical connection will disable the rotor connections, writing an error message to the message area.

During an active pass with Rotor Control enabled, Manual movement, Park or Stop will disable the Rotor Control and an appropriate warning status message issued.

Clear

Clears the message area.

Log

Opens the Contact Log dialog to create a contact log record. If the control is pressed during an active pass, relevant satellite information is automatically populated.

User Satellite Tracking

User Satellite Tracking plots the orbital path of a satellite under user control. The user is able to move the satellite forward and backward within its orbital path and read path pass information derived from the satellite position.
Orbital path and satellite positioning is displayed as with normal satellite passes and the pass information is displayed using the familiar satellite pass format.

User Satellite Tracking is helpful when determining the actual orbital characteristics of a new satellite, checking out a satellite or diagnosing problems with existing satellites.

Tracking a Satellite
The satellite is selected by pressing the Select Satellite control which uses the Satellite Selection dialog to locate the requested satellite.

The 'Matching' wildcard character '*' can be entered as the last character of the satellite name to produce a list of all satellites with names starting with and matching the entered characters up to the matching wildcard character. The 'Includes' wildcard character '#' as the last character in the entered name will result in a list of all satellite names that contain the charactes up to the wildcard character.

The satellite of interest can be selected from the list.

The Two-Line Element (TLE) from that selection determines the orbital characteristics of the tracked satellite.
After selection, the satellite name and satellite catalog number are displayed.

Satellite Tracking Controls

Select

Selects satellite to plot based on date-time setting.

Date-Time Selector

Selects starting date and time for satellite plot.

Orbits

Number of orbits to plot for satellite.

Minimum Elevation

Sets the minimum elevation for a displayed pass. The default is 10 degrees.

Step Value

The difference in time between successive positions along the satellite path with manual or automatic stepping.

Step Rate

Sets the step value in units of seconds or minutes.

Step Controls

Satellite Step Controls

Reset

Sets the satellite orbit path and starting point to the selected date and time.

Back

Steps the satellite position back one Step Rate interval.

Forward

Advances the satellite position forward one Step Rate interval.

Pressing and holding either the Back or Forward control for more than one-half second activates fast step that advances the satellite's position in the selected direction by the Step Rate interval ten times per second. Releasing the control stops the automatic step movement.

Run controls are disabled until a satellite is selected.

The date-time value is set to the current date-time when User Tracking is started. The Daylight Terminator will show on the map if enabled.
Pass values displayed in the right zone are position information based on the current satellite position along the orbit path as determined by the step controls. The displayed time is the satellite position time.

Note:  When switching between normal satellite tracking and user satellite tracking, pass options and selections are reset.

Installation

Instances

Multiple copies of OsTrax can be simultaneously run.
Each copy is known as an Instance with the normal single instance known as the Default Instance.
Each Instance is independent, sharing only Instance definitions, which allows for unique configurations on a single machine.

Before multiple OsTrax instances can be started, Instances must be defined in Settings->Preferences->General->Instances; created or deleted by clicking on Manage Instances.

To add an instance, click Add and enter a unique name for the instance. The name must begin with an upper-case alpha character followed by a combination of alphanumeric characters, including dash - and underscore _ characters. Spaces are not allowed. The maximum name length is 20 characters.

To delete an instance, double click on the name entry and click Confirm on the delete confirmation dialog that follows.
When an Instance is deleted, all preference settings and definitions are deleted.

With Instance are defined, at start-up, OsTrax will present an Instance selection dialog where an instance can be selected.
Only one copy of an instance can be active at a time. If an instance is selected that is currently active a warning dialog will appear and the start attempt ended.

The selected Instance name will appear on the OsTrax screen at the far right on the top line. If the instance is the default instance, the name does not appear.

Operation

This section provides guidelines for using OsTrax to track satellites and to make a radio contact or receive information from a satellite.

Satellite Passes
Satellite passes form the basis for all OsTrax activities. Satellite passes are defined by adding satellites to the active Satellite Group using the Select control at the bottom of the right zone.

Satellite Groups are created, managed and selected using Settings->Satellite Group. The name of the active Satellite Group is displayed above the Upcoming Passes list in the right zone.
Satellites can be deleted from the active Satellite Group or a new Satellite Group created using satellites defined in the active group by clicking the Active control.

Current Pass describes the current satellite and available communications links. Current does not indicate the pass is active, that is controlling the radio and rotor. At LOS, the pass is deleted and the next available pass in the Upcoming Pass list promoted to current. The current pass orbit is plotted even when the pass is not active.

Clicking the End Pass control immediately terminates the pass and promotes the next available pass in the Upcoming Pass list to become the current pass.

Unless the pass was manually Selected or all passes selected in Settings->Preferences->Pass->Auto Pass Select the Start Pass control must be pressed for the pass to become active. Once the pass is active and the satellite has reached AOS or AOS Prestart, the radio and rotor begin updating based on the current position of the satellite.

With the pass active, the Start Pass control changes to Extend Pass. Each press of the Extend pass control extends the pass beyond LOS by the time period set in Settings->Preferences->Pass->Extend Pass Time. Extended Pass times are cumulative, each press of the control extends the LOS time by the settings value.

Upcoming Passes list future satellite passes in chronological order based on satellites defined in the active Satellite Group with modifications indicated.

Satellites with similar passes over a ground station will frequently create situations where one pass must be preferred. OsTrax uses Pass Priority to draw attention to priority situations allowing the operator to make decisions as to which satellite pass to favor.

Each entry in the Current Pass list contains a color status area that indicates pass conflict status.
Yellow indicates the pass starts after the pass before it in the list but ends after the prior pass ends (LOS) meaning some of the pass may be usable.
Red indicates the pass starts after the pass before it and ends before the prior pass ends meaning the pass will not be usable.
The absence of any color indicates no pass conflict exist.

Pass priority can be altered by left clicking the pass entry and changing the Pass Options selector.
For example, if the desired pass status is Yellow or Red and the pass ahead is of no interest, changing Pass Options to Schedule on the desired pass and changing Pass Options to Exclude on the pass above it will result in the excluded pass being ignored and the desired pass automatically started.

If the status is Yellow, setting Pass Options to Schedule will automatically start the selected pass when the one above it in the list ends.
If the undesired pass is the Current Pass, changing Pass Options to Schedule and clicking the End Pass control will terminate the Current Pass and automatically start the the selected pass at the appropriate time.

Radio and Rotor
It is assumed OsTrax has been installed and a radio and rotor controller defined as described in Installation.

With a radio and rotor controller defined, when OsTrax is started the Radio and Rotor controls at the bottom of the screen should be enabled indicated by the control being highlighted. A control not enabled is an indication that the serial connection is not correct which will be indicated by an error message in the comport status for the control.

Note:   Even with an established connection, communication with the device will fail if the Baud Rate selection for the device is incorrect or an incorrect Comport was selected.

Radio Control
Located in the Radio view, Control selects if the radio is to be managed by OsTrax, configuring the radio for a satellite communication link and sending and receiving frequency updates. Control is disabled by default and must be enabled before OsTrax can send control messages to the radio. During operation, Control can be disabled to temporarily stop OsTrax updating the radio.

The Set control is activated when Control is enabled. Clicking Set sends control commands to the radio to set the radio frequency to the communication link frequency. For Transponder communication links the frequency is set to the passband center frequency.

Doppler Shift, Satellite Frequency, Radio and Offsets remain disabled until an active satellite pass begins.

When the satellite pass ends, these areas disabled until the next active satellite pass.

Satellite Selection

Satellite Selection uses selected options to search for a list of all satellites matching the selection criteria. Various versions of the selection dialog are utilized in OsTrax but all share a common look and feel.

Satellite Selection Options

Satellite Name or Catalog Number

Search for a satellite based on name or catalog number or search by communication capability.

For name or catalog number searches, only one of the search arguments can be entered and no communication capabilities can be selected.

For communication capability searches neither the satellite name or catalog number arguments can be entered.

The satellite name entered may be terminated with one of two wildcard characters and the returned satellite list will contain all satellites meeting the wildcard criteria. Only one wildcard character can be used.

The wildcard characters are:

*     Match wildcard. Matches any satellite name that begins with the characters prior to the wildcard character.
#    Contains wildcard. Matches any satellite name that contains the characters prior to the wildcard character.

The wildcard character can only appear at the end of the satellite name or to list all satellites in a selected source the wildcard character is entered as the only entered character.

Orbital Element Source

The selected sources are searched in listed order. A list of all satellites, including duplicate entries, meeting the selection criteria is displayed.

At least one orbital element source is required and selected sources are remembered for faster selection on subsequent invocations.

Communication Capabilities

When searching for a non-specific satellite (satellite name and catalog number omitted) returns a list of satellites matching the selected communication capabilities.

The selection results are displayed in alphabetical order by name. Selecting a satellite will add it to the Active Satellite Group when Add control is clicked if the satellite is not currently a memeber of the group. Unselecting a satellite will remove it from the Active Satellite Group when the Add control is clicked..

Satellite Groups

Satellite Groups are named list of satellites, grouped together for operating, contest, telemetry, remote, Field Day or any desired combination.

When a Satellite Group is selected, the satellites in the group replace the current satellite list and passes for the group's satellites are recalculated.

Satellite Groups are defined for ground stations with unlimited number of Satellite Groups for each ground station.
Each Satellite Group can contain a unlimited number of satellite.

Only one Satellite Group can be active at a given time. The name of the active Satellite Group is displayed above the Satellite Pass List in the right zone.

Creating a Satellite Group

A Satellite Group is created from Menu->Setting->Satellite Group and pressing the Add Group control.

This opens the Satellite Group dialog where the name for the group is entered and optionally, satellites selected to be included in the group.

The Satellite Group name must be unique, begin with an upper case alphabetic character and is limited to 20 characters in length.

Satellites may be added to the group before the group is created or later by editing the Satellite Group.
Satellites are selected using the standard satellite selection process which allows wildcard name selection from different satellite sources and may be selected.

The Satellite Group is created by pressing the Create control which creates the new group for the Ground Station using the selected satellites.

Satellites can be excluded from the new group by unclicking the selection control next to the satellite name.

Editing or Deleteing a Satellite Group

A Satellite Group can be deleted or edited by selecting the group from Menu->Settings->Satellite Groups by double clicking on the list entry.

To delete the group, press the Delete control and reply positively to the delete confirmation dialog.

The Satellite Group name can be changed by entering a new, unique name beginning with an upper case alphabetic character, limited to 20 characters in length.

Satellite can be removed form the list by unclecking the selection control next to the satellite name in the list.

New satellites can be added by pressing the Add Satellite control and following the selection process.

All changes become effective when the Update control is pressed.

SdrSharp (SDR#) Plugin

SDR# receivers use the OsTrax SDR Plugin available from the OsTrax github site (https://github.com/ostrax).
OsTrax manages the SDR# receiver, setting the communication link modulation mode and adjusting receiver frequency due to doppler changes.

With passband communication links and with the SDR# Receiver paired with a transmitter, altering the frequency on the SDR# receiver alters the transmit frequency according to the communication link characteristics.

The plugin has been tested using Airspy, FunCube Pro and SDRPlay receivers using SDRSharp as the controlling software.

Installation
To install the OsTrax SDR# Plugin.

1. Create a folder called "OsTrax Controller" in the "Plugins" folder of SDRSharp.
2. Download the SdrSharp.OsTraxController.dll file from the OsTrax github site (https://github.com/ostrax) and place it in the OsTrax Controller folder created in the step above.
3. Start SDRSharp. The plugin should be listed and available for use.

Using

1. With the plugin installed and SDRSharp running, determine the virtual comport for the plugin.
2. From Settings->Radios in OsTrax;
   1. Select SDR# as the receiver.
   2. In the Comport drop-down list, select the serial port for the SDR# controller.
   3. In the Baud Rate drop-down list, select 115200 as the communication rate.
3. Click Select to complete the selection.
4. Start the OsTrax Controller plugin in SDRSharp.
5. When the next active satellite pass occurs, the OsTrax Controller display in SDRSharp will show the satellite name, modulation mode and receive frequency.

Radio Selection

Radio selection is made using Menu->Settings->Radio 1 and/or Radio 2.

Radio 1 is the normal selection when a single radio is in use.

A total of two radios can be selected for simultaneous operation. If two radios are selected, the first radio will be designated as Downlink (receive) only and the second Uplink (transmit) only.

Radio 1 must be selected before Radio 2 can be selected. Radio 2 must be deselected (set to No Radio Selected) before Radio 1 can be deselected or the Radio 1 selection changed.

Radios defined as TxRx do not have satellite capability and can only send or receive. Send or receive for TxRx radios is set by selecting one of the Capability options on the list entry for the radio which is only available for TxRx radios.

For a list of all radios supported by OsTrax refer to Supported Radios.

A radio is selected by clicking the appropriate Selected column entry which will replace any prior selection.
Next the comport for the radio is selected from the Comport selection box and the Baud Rate for the port and radio set to match the baud rate setting in the radio's menu or as indicated in the radio user manual.

For Icom radios, the radio address must be set to match the physical radio address set in the Icom radio menu. OsTrax displays the default address defined by Icom for the radio.

Once the radio selection is complete (radio selected, comport and baud rate set) the Select control will highlight. Clicking the control completes the radio selection.

Reselecting a Radio
Once a radio has been selected the Select control is deactivated to prevent inadvertent selection. The control is activated when either the radio, comport baud rate or radio address is changed.

Rotor Selection

Rotor controller selection is made using Menu->Settings->Rotor Selection.

A rotor controller is selected by clicking on the controller entry in the Controller box then selecting the appropriate Comport and Baud Rate for the controller from the selection boxes.

For a list of all supported rotor controllers, refer to Supported Rotor Controllers.

When the controller, comport and baud rate are selected, the Selection control becomes available. Pressing the control completes the controller selection.

Setting Controller Options

Note:  OsTrax is not able to determine the capabilities of rotors attached to a rotor controller. Incorrect controller definition may lead to rotor and/or cable damage. It is the responsibility of the person defining the controller to ensure the controller definition matches the physical capabilities of any attached rotors and cables.

Configuration options are determined based on the capabilities of the selected rotor controller.

• The rotor controller can be configured to be Azimuth only or Azimuth and Elevation.
• The controller can center North or South. If South is selected, the maximum Azimuth is automatically set to 360 degrees.
• Azimuth can be limited to 360 or 450 degrees.
• Elevation can be limited to 90 or 180 degrees.
• Rotors and controllers that support controller defined azimuth and elevation limits can select Rotor to make use of the feature.
• Precision sets the degree of azimuth and elevation positioning for rotors and controllers that support fine grained precision.

The combination of rotor controller Azimuth type and Azimuth and Elevation settings determine to pass tracking capabilities for the controller, including Flip Mode.

Reselecting a Rotor Controller
Once a rotor controller has been selected the Select control is deactivated to prevent inadvertant selection. The control is activated when either the controller, comport or baud rate is changed.

Controller Notes:
The Green Heron RT-21 controller requires two USB ports which are made available when the controller is selected. The first USB port is the Azimuth controller and the second, the Elevation controller.

Rotors and controllers that support software set azimuth limits must ensure the physical rotor and all cables are capable of the selected rotation limits.

The LVB Tracker and Fox Delta controllers should use the Yaesu GT-232 controller selection and set the Baud Rate to 9600.

Radio Offsets

Beacon and Telemetry

The offset is applied to the receive downlink frequency only.

FM Repeater and FM Simplex links

Offsets are applied independently to both the uplink and downlink frequencies.

Transponder

Transponder links are more complicated. Greater variety in operational frequencies is possible within the passband of the linear transponder, and the uplink frequency is determined by the downlink frequency. Moving the receiver (downlink) frequency has the effect of moving the transmit (uplink) frequency based on the characteristics of the satellite transponder.

OsTrax adjusts the current downlink frequency for doppler shift and sends the changed frequency to the receiver, thereby changing the receive frequency.
OsTrax then calculates the uplink frequency based on the transponder's offset and doppler shift and updates the transmit frequency in the radio to "match" the downlink frequency. In theory, an uplink signal should be precisly on frequency with the observed downlink frequency. In practice, users observe that many radios present an apparent "shift" in frequency due to the variability of how radio manufactures interpret and implement the radio frequency (RF) versus the audio frequency (AF) in transceivers.

For example, Icom radios appear to have an apparent 1700hz shift when comparing RF to AF frequencies. Furthermore, some radios are simply off frequency on one or more bands used for satellite communications. Therefore, some correction or offset becomes necessary.

OsTrax addresses the needed corrections by independently applying offsets to the uplink and downlink frequencies.

An uplink offset is applied to the calculated uplink frequency to compensate for any variations in the satellite receiver-transmitter link.

A downlink offset is applied as a correction to the downlink receiver frequency to compensate for any receiver errors without altering the uplink frequency calculation.

Although both uplink and downlink frequencies can be adjusted it is recommended that only the uplink offset be used to align the uplink frequency to the downlink frequency being received and use the downlink offset to correct for minor tuning requirements, that will not affect the uplink frequency.

Flip Mode

Satellite Footprints

Source Status

Orbital Elements files describe the orbital characteristics for satellites used to determine the position of a satellite at a given data and time. Orbital Element files are the drivers that determine the position of a satellite and determine the reference location for a satellite to direct a rotor system to aim an antenna toward the satellite.

Orbital Element files originate from information gathered by government and private agencies then distributed by various means.
OsTrax uses orbital element sources from AMSAT and optionally CelesTrak, which provide a wide range of satellites grouped by function type.
Satellites are primarily identified by an assigned catalog number unique to each satellite. Satellite names can vary based on county of origin. language and official designations and can be different between different Orbital Element file sources. OsTrax uses the AMSAT name whenever present for consistency.

Satellite orbits are continually changing based on height, speed, atmospheric drag and aerodynamic shape. In addition, many satellites can alter their orbits. Frequent updates must be made to Orbital Element table elements to compensate for orbital changes.

Source Status list the status of each available orbital element source.

A checkmark in the Active column indicates if a source is active and available for pass selection.

An Orbital Element source may be selected to be included during satellite pass selection by clicking the Active column entry for the source then pressing the Update control. Deselection of an element occurs when the Active selection is removed followed by pressing the Update control.

For active sources, the last update time is inspected at regular times as set in Settings->Preferences->Pass->Source Update Interval. At each interval, active Orbital Element sources are inspected for updates and if an update is required an ‘Source Updates Available’ control message appears in the information area on the top zone which is reset when the updates are complete.

Double clicking the message will initiate the updates or the Update control in the Sources Status dialog clicked to initiate the update.

The time of the last update is listed for each active orbital element and if an update is required the checkmark is set in the Available column for the orbital element.

The Satellite Profile Repository, which defines the communication link capabilities for a satellite, is maintained in the same manner as orbital element sources.

Controls allow updating the Orbital Element and Satellite Profile sources. If an update is required for any Orbital Element source or the Satellite Profile source the Update control is enabled. If no updates are required, the Update All control is made available to force updates of all activeOrbital Element sources and the Satellite Profile source.

Under normal operating conditions, use of this control should not be necessary.

Note:  Previous pass selection as described in Upcoming Passes may be reset when Orbital Element files are updated.
Orbital Element updates should be scheduled prior to pass selections.

Pass Predict

Transverters

System Requirements

Backup and Recovery

Support

Acknowledgments & Credits

OsTrax License Agreement

Entire contents copyright 2026 by Avinstar, LLC.

OsTrax and its accompanying programs and files are protected by copyright 2026 Avinstar, LLC. No portion of these programs or files may be sold, given away, reproduced, or otherwise distributed without written permission from Avinstar, LLC. Licensees have the non-exclusive right to use these programs and files but you do not own them; title to the programs and files is retained by Avinstar, LLC.

Avinstar, LLC License Agreement

OsTrax (the SOFTWARE, including images and data included into or with the program) is owned by Avinstar, LLC and is protected by United States copyright laws and international treaty provisions. Therefore, you must treat the SOFTWARE like any other copyrighted material (e.g. a book or musical recording) . Any other reproduction or distribution of this program without written permission from Avinstar, LLC is prohibited.

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No Other Warranties

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The SOFTWARE and documentation are provided with RESTRICTED RIGHTS. Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subparagraph (c)(ii) of the Rights in Technical Data and Computer Software clause at DFARS

252.227-7013 or subparagraphs (c)(1) and (2) of the Commercial Computer Software-Restricted Rights at 48 CFR 52.227-19, as applicable. Manufacturer Avinstar, LLC, Birmingham, Alabama.

If you acquired this product in the United States, this Agreement is governed by the State of Alabama.