Earthdata Forum

Hi,
I did L2 to L3 processing (using l3mapgen) but I noticed that the pixel coordinates interval step is not the same/exact (well, they are up to four or five decimal points). For example:
Latitudes           Step size          Longitudes  Step size
-10.005208  -0.01041700  142.005203  0.0104220
-10.015625  -0.01041600  142.015625  0.0104060
-10.026041  -0.01041700  142.026031  0.0104220
-10.036458  -0.01041700  142.036453  0.0104220
-10.046875  -0.01041600  142.046875  0.0104060
-10.057291  -0.01041700  142.057281  0.0104220
-10.067708  -0.01041700  142.067703  0.0104220

I used the command below with smi projection:
    p4 = subprocess.Popen(['l3mapgen',
                           'ifile=' + l3bfile,
                           'ofile=' + l3mfile,
                           'oformat=' + 'netcdf4',
                           'oformat2=' + 'png',
                           'product=' + l3bprod,
                           'resolution=' + '1km',
                           'projection=' + 'smi',
                           'interp=' + 'nearest',
                           'west=' + '142.0',
                           'east=' + '156.0',
                           'north=' + '-10.0',
                           'south=' + '-26.0',
                           'apply_pal=' + 'yes',
                           'palfile=' + 'universal_bluered',
                           'scale_type=' + 'log',
                           'datamin=' + '0.01',
                           'datamax=' + '20.0'])
What projection should I use in l3mapgen so that I get equal distant pixels? This is important such that when I do some spatial analysis on my dataset that requires me to specify pixel interval, I will be able to specify one value for each along Latitude and Longitude and not lose a pixel in each direction because of the inconsistent pixel interval. Thank you in advance for your time and patience.

Cheers,
Tess

The differences in step size you see are a consequence of the floating point arithmetic used in digital computers.