This paper describes the results of an analysis of radar backscatter and attenuation data collected during field trials of the MMW Module of the XM56 Large Area Screening Generator. The trials were conducted by Edgewood Research Development and Engineering Center personnel at Dugway Proving Ground in 1989 and 1990, and at Eglin AFB in 1992. The purpose of this analysis was to use inversion techniques, similar to those developed for lidar systems, to translate the radar backscatter data from the XM56 smoke clouds into estimates of cloud concentration, and to compare the resulting concentration estimates with those produces by independent, point sampling nephelometers. Three dimensional cloud concentration profiles have been produced and were found to be consistent with the Pasquill stability category. In addition, the overall correlation between the radar-generated concentration data and those collected using the nephelometers was quite good. Examples of these results are presented for the 1989, long range trials, which allowed characterization of a large volume cloud, and the 1990 and 1992 trials, which were performed over a much shorter range, but provided more useful nephelometer data.