Aperture synthesis imaging of colored GEO objects
Interferometry provides the only practicable way to image satellites in Geosynchronous Earth Orbit (GEO) with sub-meter resolution. The Magdalena Ridge Observatory Interferometer (MROI) is being funded by the US Air Force Research Laboratory to deploy the central three unit telescopes in order to demonstrate the sensitivity and baseline-bootstrapping capability needed to observe GEO targets. In parallel, we are investigating the resolution and imaging fidelity that is achievable with larger numbers of telescopes. We present imaging simulations with 7- and 10- telescope deployments of the MROI, and characterize the impact of realistic spectral variations compared with a “gray” satellite.
Abstract Many human operations have created a large population of small orbital debris in near Earth environment. The threat they represent for satellites is a major factor for the preparation of future space missions. Several experiments devoted to the study of this environment, as well as various materials exposed to space, have been retrieved in the past few years. The analysis of the results shows some differences with previous modeling. Comparison with data from LDEF and from EURECA give some insight in the long term evolution of particle size distribution. Chemical identification of particle remnants inside craters is difficult but provides valuable information on the origin of the impactors. Permanent monitoring of environment is obviously needed, especially for the type of orbits where data are presently scarce ie. heliosynchronous and geostationary orbits.