Single Satellite Geolocation
IFT’s SSG solution includes a single satellite running a doppler-based constrained unscented Kalman filter (cUKF) and several portable ground-based reference emitters. Blind Doppler estimation and online ionosphere compensation are enabled to obtain the meter-level passive geolocation of Electromagnetic interference (EMI) sources on the ground.
The core part of the SSG is the cUKF based on the Doppler information, which is be blindly estimated from the received electromagnetic interference (EMI) signals. Serval Software-defined radio (SDR) based portable reference emitters are designed to mimic Electro Magnetic Interference (EMI) sources for training purpose of the cUKF based SSG. The reference emitters are also used to mitigate the ionospheric effects.
SSG Technical Overview:
– 3-D geolocation accuracy 18 meters
– Dual working modes of the reference emitters: on-call and online
– Stand deviation (std) of Doppler estimation: less than 60 Hz for C band frequencies and SNR levels greater than 0 dB
– 3dB improvements due to the online Ionosphere mitigation
METHOD: cUKF, blind estimation, Electro Magnetic Interference sources mimicking, cUKF-based SSG training, ionospheric effects mitigation
KEYWORDS: Blind estimation of Doppler, Cross-correlation, Ionosphere Estimation and Compensation, constrained unscented Kalman filter (cUKF), multi-mode.
TECHNICAL SPECS: 3-D geolocation, dual working modes, Stand deviation of Doppler estimation, 3dB improvements