L1B -- NOAA Polar Orbiter Level 1b Data Set (AVHRR)

GDAL supports NOAA Polar Orbiter Level 1b Data Set format for reading. Now it can read NOAA-9(F) --- NOAA-17(M) datasets. NOTE: only AVHRR instrument supported now, if you want read data from other instruments, write to me (Andrey Kiselev, dron@ak4719.spb.edu). AVHRR LAC/HRPT (1 km resolution) and GAC (4 km resolution) should be processed correctly.


Note, that GDAL simple affine georeference model completely unsuitable for the NOAA data. So you should not rely on it. It is recommended to use the thin plate spline warper (tps). Automatic image rectification can be done with ground control points (GCPs) from the input file. NOAA stores 51 GCPs per scanline both in the LAC and GAC datasets. In fact you may get less than 51 GCPs, especially at end of scanlines. Another approach to rectification is manual selection of the GCPs using external source of georeference information.
Precision of the GCPs determination depends from the satellite type. In the NOAA-9 -- NOAA-14 datasets geographic coordinates of the GCPs stored in integer values as a 128th of a degree. So we can't determine positions more precise than 1/128=0.0078125 of degree (~28"). In NOAA-15 -- NOAA-17 datasets we have much more precise positions, they are stored as 10000th of degree.
Image will be always returned with most northern scanline located at the top of image. If you want determine actual direction of the satellite moving you should look at LOCATION metadata record.


In case of NOAA-10 in channel 5 you will get repeated channel 4 data.
AVHRR/3 instrument (NOAA-15 -- NOAA-17) is a six channel radiometer, but only five channels are transmitted to the ground at any given time. Channels 3A and 3B cannot operate simultaneously. Look at channel description field reported by gdalinfo to determine what kind of channel contained in processed file.


Several parameters, obtained from the dataset stored as metadata records.

Metadata records:

See Also: