Detecting Ships in the New Zealand Exclusive Economic Zone: Requirements for a Dedicated SmallSat SAR Mission

The performance trade-offs of a SmallSat Synthetic Aperture Radar (SAR) system for maritime surveillance in thecoastal waters of New Zealand are investigated. The lower costs of SmallSat platforms allow for a constellation of SAR satellites thatcan be launched from New Zealand using an existing local launch service provider. The minimum SAR image quality necessary fora SmallSat system to achieve a desired detection performanceis determined using existing X-band satellite data. The imagequality is specified in terms of Noise-Equivalent Sigma Zero (NESZ) and resolution. It was found that for a resolution cell of 4 m^2 a system NESZ of −1.7 dB is sufficient to detect small fishing vessels with a probability of detection of 0.5, while maintaining the Probability of False Alarm below 10^−10. These requirements are translated into a preliminary SAR system design.