Satellite Orbit and Ephemeris Determination using Inter Satellite Links

Inter Satellite LinksSimulations and Results6.2.5 Pure LEO Constellation6.2.5.1 Ground Tracking with Full NetworkIn this scenario, orbit determination for the LEO constellation has been done using groundmeasurements only, but with a large scale network of ground stations. Using the DORISnetwork provides a good tracking accuracy for LEO satellites. This is due to the large numberof tracking stations, distributed over the world. A radial accuracy of better than 30 cm can bereached most of the time. Although LEO satellites have a higher along track error due to theuncertainty in the high altitude air density, a LEO satellite tracked by a large ground networkcan be seen from more than 5 stations the whole time. Due to the low altitude, the trackinggeometry is also good.Radial Error [cm] 1998 07 02 05:24 - 1998 07 09 11:2450.025.0Radial Std. Dev. [cm] 1998 07 02 05:24 - 1998 07 09 11:2432.0016.0-25.0-50.0[h]41 82 123 1640[h]40 80 120 160Along Track Error [cm] 1998 07 02 05:24 - 1998 07 09 11:2498.049.0Along Track Std. Dev. [cm] 1998 07 02 05:24 - 1998 07 09 11:2444.0022.0-49.0-98.0[h]41 82 123 1640[h]40 80 120 160Cross T rack Error [cm] 1998 07 02 05:24 - 1998 07 09 11:2434.017.0Cross Track Std. Dev. [cm] 1998 07 02 05:24 - 1998 07 09 11:2416.008.0-17.0-34.0[h]41 82 123 1640[h]40 80 120 160Figure 6-30 Tracking Accuracy of LEO using DORIS Network onlyR. Wolf Page 125