Evaluation of the WSR-88D Network for Tracking Satellite and Space Debris: Initial Observations and Implications

The WSR-88D radar network, primarily designed for weather surveillance, has demonstrated potential utility in tracking high-altitude targets, including satellites and space debris. This study presents initial observations from the WSR-88D radar located at Norman, Oklahoma (KOUN), and discusses the implications of these findings for future space situational awareness applications.

On January 6, 2023, the WSR-88D at KOUN was configured to observe targets at high altitudes. The radar was set to scan from 45° to 59° in elevation at a fixed azimuth of 0° (north). The pulse repetition frequency (PRF) was 300 Hz, giving an unambiguous range of 500 km. The radar utilized 32 pulses per calculation with a long pulse, resulting in a radial resolution of 0.501 km. A Doppler notch filter was applied to exclude targets with radial velocities within ±1 m/s. Observations were analyzed for signal-to-noise ratio (SNR) and correlation coefficient between horizontally and vertically polarized waves.
The radar successfully detected a high-altitude target over a 1.49-second period. The target's SNR peaked at 20.5 dB at an estimated range of 645.79 km, likely placing it within the second unambiguous range interval. The correlation coefficient between polarized waves (Rhv) was observed to be high (0.97), indicating a consistent signal reflective of a space object. The radar's current PRF settings and susceptibility to interference were noted as limitations. The findings suggest that the WSR-88D network could be adapted for tracking space debris and satellites by optimizing the radar's PRF and mitigating interference. Reducing the PRF to 200 Hz could extend the unambiguous range to 750 km, improving the radar's capability to monitor distant space objects. Additionally, the high correlation coefficient indicates that polarization data could be critical in distinguishing space targets from other clutter.

This initial study demonstrates the WSR-88D's potential for space debris and satellite tracking, suggesting that with further refinement, this existing radar network could contribute to space situational awareness. Future work should focus on testing lower PRFs, interference removal techniques, a space VCP and exploring solid-state radar transmitters to enhance performance.