This page displays images of echo statistics created using a program package by Donaldson and Patterson. The "raw program" runs on a machine running URP gathers up all META files in 5 day periods of each month, e.g. March 1-4, March 5-9, etc. for a particular URP product, typically PPIs of DBZ and DBT, and builds distributions of observed reflectivities at every pixel. The analysis program gathers up 5 day statistics periods in a particular year/month and makes multiple statistics: mean reflectivity median reflectivity mean rainfall rate (MP) percent of NULL observations percentage of observations above a threshold etc.

Here are frequency distributions of reported echo strengths as a function of range. "Frequency" is loose, because the number of observation is normalized by number of files processed. The echo strengths are in terms of engineering units from data files (N values).

2020 - Added "filtered" version. This attempts to build statistics using pixels that are not badly clutter contaminated. It rejects pixles where the percentage of "zero" (0/NULL) is very low (data always present) or too high (always rejected). This is far from perfect, particularly at long range where the percentage of "zero" is always high-ish. At long ranges the algorithm is more forgiving of high percentages. Another issue is that in some cases essentially no pixels pass the test at close range and no distribution is calculated.