With the rise of commercial constellation implementation in low earth orbit (LEO), the near-Earth space environment is becoming increasingly challenging to monitor and protect. As well as carefully considered policy frameworks, new observational techniques and instrumentation are needed to ensure that safe operations can be maintained by all space users. The Pervasive Sensing group at the University of Birmingham is exploring in-orbit conditional monitoring of satellites using inverse synthetic aperture radar (ISAR) as a technique for dedicated observation of high-value space-based assets. Our previous concept and design results for fixed-beam dual freqency ISAR observations in circular orbits have been extended to a variety of scenarios. I will discuss some of our recent results from both experiments and simulation.