GPS Setup

Use this button to set the online options for the GPS Propagator.

Option	Description
Use all relevant elements	This option will use every available almanac in the interval of interest. This option is only available in Online mode.
Switching Method	Defines when to switch between almanacs. This option is only available in Online mode. Epoch - Switch between almanacs based on the epoch of the almanac. MidPoint - Switch between almanacs based on the mid-point between two almanac epochs. TCA - Switch between almanacs based on the time of closest approach. Calculated by propagating each almanac of a pair over the time period between their respective epochs, and then determining the point at which the two paths are nearest each other. This option provides the smoothest possible fit between two almanacs but may not represent the best estimate of the ephemeris.
Use first relevant element	This option will use only the first available almanac. This option is only available in Online mode.
Almanac File	This will allow you to select an external almanac file to be used with automatic update from file mode. This option is only available when you select Automatic - File.