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

Abstract

The performance tradeoffs of a smallsat synthetic aperture radar (SAR) system for maritime surveillance in the coastal waters of New Zealand are investigated. The lower costs of smallsat platforms allow for a constellation of SAR satellites that can be launched from New Zealand using an existing local launch service provider. The minimum SAR image quality necessary for a smallsat system to achieve a desired detection performance is determined using existing $X$-band satellite data. The image quality 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.

Keywords

• Synthetic aperture radar
• radar remote sensing
• low earth orbit satellites
• satellite antennas
• detectors
• spaceborne radar