Another weather satellite pass…

December 30, 2007 | Amateur Radio, Amateur Science, My Projects | By: Mark VandeWettering

Well, during a road trip with my wife to San Diego and back, I managed to begin to type up my notes for an upcoming tutorial article (cross fingers) on reception and decoding of weather satellite imagery. I basically reimplemented what I had, stripping it down to its barest essence, and trying to make it easy to understand, yet still capable of creating good imagery. Oddly enough though, in the process, I inadvertently seemed to introduce some aliasing artifacts which I must admit, are puzzling me mightily. Oh well.

This morning I decided to try to record a low 25 degree maximum pass of NOAA17 that occurred to the east. It starts out fairly noisy because I have a pretty high horizon to the northeast. The first is my “advanced” decoder, which is about six times longer than the simpler decoder I wrote.

My “advanced” decode…

The second is the same data file, processed with my “simple”, easy-to-follow decoder. The only serious feature it is lacking is the sync detection and rectification, which as soon as I can figure the simplest way to add, I’ll try to get in. The simple version is two pages of code, not including the data for the filter tables.

My “simple” decode