In this paper, the Cramer-Rao bound for target parameters from a space based radar platform is derived. In particular, the bounds for target Doppler and power are derived under a variety of conditions - target in white noise, target in clutter and noise case. In the later case, the performance is analyzed with range foldover and in the presence/absence of earth's rotation. When both these phenomena are present, the bound is shown to be inferior compared to other situations where only either effect is present. In the general case, methods such as waveform diversity should be considered for superior target detection.