Satellite-to-satellite tracking with POPSAT and an ERS-class satellite. Mission and system assessment study. Volume 1: Executive summary

Orbit determination error analyses were carried for satellite-to-satellite tracking (SST) alternatives, on global and local scales. It is shown that radial orbit determination accuracies in the range of interest for radar altimetry applications can be achieved. Error analyses show that imperfect knowledge of the Earth gravity field introduces the dominant error contribution. Tracking concepts for precise low Earth orbit determination must be judged by their capability to provide accurately tailored gravity field models. Although the ultimate accuracy limits of gravity field determination are not established, deterministic simulations demonstrate that SST from POPSAT is the superior method for setting up dedicated gravity field models for LEO satellites and that improvements by a factor of six compared to SEASAT appear achievable. The selected SST concept was functionally defined. The performance of the S-band intersatellite link was analyzed and error budgets were set up.