NTU EEE Final Year Project - Feasibility Study of a Satellite-Based Passive Radar
Radars come in all shapes and sizes. Some radars are overt, and some radars are covert. This project delves into the world of covert radars. Unlike active (overt) radars, passive (covert) radars do not transmit a signal to track a target. Instead, they exploit the signals transmitted by other sources.
- Historical Context: Passive radar has been used since WWII (e.g., German exploitation of British radars).
- Modern Relevance: Silent, covert operations; Useful for detecting stealth aircraft
- Antenna: Log-Periodic Dipole Array (LPDA) simulated and deployed.
- Setup: Separate reference and surveillance antennas, 5m apart, deployed near Changi Airport.
- Signal Processing Chain: Removing Direct Path Interference of Reference in Surveillance, Matched Filtering
- Implementation: GNU Radio for real-time processing and MATLAB for post-processing.
- DVB-T2 Field Tests: Aircraft approaching Changi Airport were detected using DVB-T2 signals at 538 MHz.
- Results: Range-Doppler maps showed moving targets (aircraft).
Challenges included:
- Bulky equipment
- Insufficient antenna height (trees blocking LOS to transmitter)
- Time synchronization issues (Linux scheduling, phase drift)
- Multipath from sea reflections reducing SNR
Here are some pictures of the test setup and field experiments:
- A DVB-T2-based passive radar works has been proven to "barely" work in Singapore despite urban clutter and short transmitter–receiver baselines.
Future improvements to this project will focus on improving synchronization, clutter suppression, and satellite-based IO experiments.