High-Accuracy Electronic Tracking of Space Vehicles

It is the purpose of this paper to show that optical accuracies can be reached with electronic tracking if the refractive index is known at the site of the radar, as well as at the site of the target. This is the case in tracking space vehicles with microwaves. The index can be measured at the tracking site and it is unity beyond the denser atmosphere. Ionospheric influences can be neglected in the higher kilomegacycle range. It is also shown that the uncertainty of the course of any particular profile between the surface of the earth and the target has only minute effects on range and angular errors. Accuracy limits are determined and presented numerically. The inherent high precision of modern electronic tracking systems can be fully utilized under these conditions; this is not the case in tracking vehicles flying in the atmosphere.