TABLE OF CONTENTS Richard Simpson
As the space age moved into full swing in the 1960s, bistatic radar became one of several tools for exploring remote planetary surfaces. Wavelengths ( ?) commonly used for space telecommunications and research were in the meter and centimeter ranges. These interact with surface structure having similar scales; with proper interpretation the results of radar scattering observations can provide unique information on root-mean-square (rms) slopes ( ?) and near-surface dielectric constant ( ?) and density ( ?) that are important in selecting sites for planetary landers and rovers. In addition, the unique microwave properties of clean-water ice make bistatic radar potentially one of the most important tools in locating sites for future habitation.
Monostatic radar has been employed for studying the moon since shortly after World War II [1, 2]; Mars [3] and Venus [4] had also been detected using Earth-based systems. But the huge cost of overcoming the R 4 factor in the denominator of the monostatic radar equation, where R is the radar-to-target range, made the bistatic geometry attractive if a spacecraft could be used on the shorter of the two legs of the path (see Section 5.2).
Originally envisioned as an uplink experiment with high-powered transmitters on Earth providing illumination, planetary bistatic radar needed a spacecraft receiver either in orbit or flying nearby to sample and record echo signals reflected from the target. The radio data could then be returned in the spacecraft science telemetry stream...
