What are the practical differences between pulse and stepped frequency radars?
There are many papers in Microsoft or Google Scholar, which I have not looked but 8 steps of pulsed step frequency , either simulataneous (harder) or incremental, can gain as much as 15 dB SNR in ground clutter rejection, in the mid 400MHz range. 

I know a former colleague went on to succeed at surface coal mining exploration using very rigid phased array fixed antenna with multi hop synthetic aperture scanning over a large area in Saskatchewan (circa 90's) before becoming Eng Mgr at BNI which produced many state of the art wireless systems before being bought out by Nortel. Unfortunately they only bought the technology and nobody wanted to move from Winnipeg, so it was a billion dollar loss another one of their bad decisions to a once great company as good as Cisco.

A worthy project is to make low cost land mine detectors for those at risk.