But what are all those monthly files? DON'T KNOW, UNDOCUMENTED. Wherever I look, there are data files, no info about what they are other than their names. And that's useless.

The IDL gridding program calculates whether or not a station contributes to a cell, using.. graphics. Yes, it plots the station sphere of influence then checks for the colour white in the output. So there is no guarantee that the station number files, which are produced *independently* by anomdtb, will reflect what actually happened!!

The problem is, really, the huge numbers of cells potentially involved in one station, particularly at high latitudes.... out of malicious interest, I dumped the first station's coverage to a text file and counted up how many cells it 'influenced'. The station was at 10.6E, 61.0N. The total number of cells covered was a staggering 476!

Back to the gridding. I am seriously worried that our flagship gridded data product is produced by Delaunay triangulation - apparently linear as well. As far as I can see, this renders the station counts totally meaningless. It also means that we cannot say exactly how the gridded data is arrived at from a statistical perspective...

Why this wasn't coded up in Fortran I don't know - time pressures perhaps? Was too much effort expended on homogenisation, that there wasn't enough time to write a gridding procedure? Of course, it's too late for me to fix it too.

...and just when I thought it was done I'm hitting yet another problem that's based on the hopeless state of our databases. There is no uniform data integrity, it's just a catalogue of issues that continues to grow as they're found.

Source: Harry_Read_Me Files - The Devil's Kitchen, N-23-09