So over the years working with elevation and image rasters in various formats I always kind of ignore the value of No Data. I usually just let the software/vendor/someone else decide on the value for me. Lately I've been giving it some thought. Why am I using this arbitrary software assigned value of:
- -3.40282306074e+038 (I assume the lowest possible float number)
- 255,255,255 (white)
- 0,0,0 (black)
Now I'm in a large process of organising and optimising our raster datasets. These datasets are elevation, analysis and aerial photography. And I am finding now is a good time to set a consistent No Data value. Personally I am thinking of using the following:
- Elevation: -1
- Air Photography: -1, -1, -1
- Analysis: -1 (when possible, does not work for all datasets)
Concerning Elevation and Air Photo raster, will setting -1 really mess up analysis done on the dataset, will it display properly and does No Data really even matter?
I've done a few tests and everything seems to work out, but are there any long term implications that I need to worry about?