Tracking Systems
icon in the Browser and in the ODTK toolbar, provides a convenient way of grouping one or more facilities and treating
them as a unit for File and Edit operations such as Save, Delete, Cut, Copy, and Paste.
You can also set tropospheric and ionospheric modeling options for the entire tracking system.
You can populate the tracking system with tracking stations manually as follows:
- Click the
icon once for each facility desired. - Define the properties of each facility.
Alternatively, you can select Import from the File menu and load one or more predefined tracking systems that include facilities (stored as an XML file) from the following location:
..\STKOD\AppData\Databases\TrackingSystem\
Tracking data is selected at the scenario level.
Importing facilities, places, and targets into a tracking system
To import one or more STK facility (.f), place (.plc), or target (.t) object files, highlight the Tracking System in the Object Browser and select Import->Import Object from the File menu. ODTK converts mported place and target objects to facility objects.
Troposphere and ionosphere delay settings
Some formats such as the GEOSC format include flags to indicate whether or not the data has been corrected (for processing purposes). In other words, if the people who generated the tracking data file already removed the effects of troposphere or ionosphere, they would set the flag indicating that they corrected the measurements.
The ODTK generic simulation format keeps track of these flags. From a simulation point of view, if you choose not to include troposphere or ionosphere for measurements, ODTK sets the flag to indicate the measurements have been corrected or that the measurements do not contain unmodeled biases. If you choose to include troposphere or ionosphere, then ODTK sets the flags indicating that the measurements do contain those effects.
When the filter processes measurements, if the tracking data flags are set to indicate that ionosphere or troposphere have already been corrected for, then ODTK ignores the user settings for modeling those effects. However, if the tracking data does contain unmodeled biases, you can choose whether or not to model those effects.
The exceptions to this discussion are the GPS CA, P1, and P2 pseudorange and phase measurements. The modeling of these effects is controlled entirely by user settings.
In the GEOSC format, a flag value of 0 means the data has been corrected and a value of 1 means the data contains the effects of troposphere/ionosphere.
If you want to simulate measurements and then be able to toggle on/off troposphere modeling and see the effects in the residuals, then simulate measurements with troposphere enabled, producing a flag of 1 in the tracking data file. Then when filtering, you can toggle the troposphere enabled flag and see the effects in the residuals.