Measuring Space Debris with Phase Coded Aperiodic Transmission Sequences

We describe a radar transmission scheme with long phase coded pulses and non-uniform inter-pulse periods (IPPs) that gives a full range coverage while maintaining high radar duty cycle. In this scheme, the range ambiguity is mitigated using a combination of phase coding and nonuniform inter-pulse periods. To demonstrate the concept, we show initial results from a recent 21-hour EISCAT UHF measurement conducted soon after the Iridium- Kosmos collision. We also discuss the possibility of using the tri-static EISCAT UHF system for measuring the orbital elements of debris.