These comparisons are made with HIRS level 1d data (HIRS, AMSU-A and AMSU-B/MHS on the HIRS grid). The level 1d files are generated using AAPP from the incoming level 1c regional data, and are compared with the corresponding level 1d files generated from global level 1b data from NOAA
Explanation of monitoring files:
- AMSU Channel 15 is a map of the brightness temperature difference between RARS and global data for AMSU-A channel 15 (89.0 GHz). For NOAA-17, AMSU-B channel 1 (also 89 GHz) is used instead of AMSU-A.
- Mapping contains a plot of the regional navigated HIRS fields of view superimposed upon the Global, providing a graphical display of the navigation error.
- All Channels shows the difference in brightness temperature for each instrument channel, plotted against the global brightness temperatures.
- Warnings are text files generated if differences between RARS and global data are above a defined tolerance. The navigation differences are recorded, together with the brightness temperature differences for each channel - standard deviation and bias. Navigation differences of a few km are to be expected for NOAA-16 and NOAA-17, because AAPP and NESDIS use different assumptions with regard to the nominal pointing of the HIRS instrument. Channels 1-20 are HIRS, channels 21-35 are AMSU-A and channels 35-40 are AMSU-B/MHS.
Station names are marked with the regional network to which they belong: [E]=EARS, [AP]=Asia-Pacific RARS, [SA]=South American RARS. The "Time of day" is not applicable to "Latest" data.