GOES-11 Brief Science Check - June 2004

GOES-11 Imager and Sounder data were ingested, served, and archived by the SSEC Data Center.

GOES-11 was taken out of storage on June 3 and went through various testing, such as communciations testing. From June 21-30 the imaging schedule was to mirror that of GOES-12. Researchers at CIMSS tested the scientific integrity of the GVAR data. This cursory review of the data did not reveal any problems with GOES-11 and all appears to be operating within expected parameters.

• Full Disk Imager
  This Java loop shows full disk images from the GOES-11 Imager on 21 June 2004 at 8:45UTC.
• 19-panel Sounder to Sounder comparison
  This Java loop shows approximately a full day's worth of GOES-11 sounder data compared to GOES-12. It runs from nominal 23UTC (22:46) on 20 June to nominal 1 UTC (00:46) on 22 June 2004. Data from both satellites are are shown in common mercator projection at an effective resolution of 27km. For some hours, some of the GOES-11 data are missing some bands; one can toggle off those hours while running the animation. GOES-11 matches reasonably well with GOES-12. The solar angle difference between satellites at 96W (GOES-11) and 75W (GOES-12) is evident in the shorter wavelength window bands where the reflected solar contribution can be seen.
• Cloud Top Pressure
  This comparison of GOES-11 to GOES-12 Sounder Cloud Top Pressure is for the nominal 15z (14:46UTC) time period on 21 June 2004 (2004173). The GOES-11 image was remapped into the GOES-12 projection. There are slight differences between the two images around cloud edges and for some high cirrus, but overall they compare very well.
  
• 3.9µm Hot Spot Detection
  This is a comparison of the GOES-10, GOES-11, and GOES-12 imager 3.9 µm (shortwave IR) and visible channels, showing large wildfires that were burning in Alaska and the Yukon Territory between 23:15 UTC / 19 June and 07:15 UTC / 20 June 2004 (4:15 PM to midnight local time).
• Imager to Imager Comparisons
  Comparisons were made between GOES-11 and GOES-12 Imager bands over the central US on 22 June 2004, 11:45UTC. Differences were calculated in McIdas on a straight line at approximately the midpoint between the two satellites (see the comparison domain). Difference images between GOES-11 and GOES-12 were created for the visible, 3.9µm, 6.7/6.5µm, and 11µm bands.

  Additionally, another Imager to Imager comparison was done between GOES-11 and GOES-12 at 8:45 UTC on 21 June 2004 at the approximate midpoint betwen the two satellites. This comparison was done on unaltered images for a 31x31 FOV area centered at 85.5W on the equator. An example for the 11µm window channel shows the comparison area highlighted in yellow. Average radiances (mW/m²/ster/cm^-1) were measured for this area and then converted to brightness temperature (K) using the Planck function. The differences between GOES-11 and GOES-12 are as expected. The results are shown below.

  SAT   BAND   CENTRAL   MEAN     MEAN
   NO    NO     WL(um)   RAD      TBB
   11    2      3.9      0.611    289.8
   12    2      3.9      0.607    289.9
   11    3      6.7      6.821    246.4
   12    3      6.5      6.621    250.1
   11    4      11.0    93.444    288.6
   12    4      11.0    93.481    288.8 
     

  McIdas code used to calculate these differences can be seen here.

GOES-11 Planck Function Constants...

 GOES-11 PLANCK-FUNCTION CONSTANTS
 (1-19=sounder,20=spare,21-25=imager)

 CHANNEL    CENT-WN      FK1          FK2        BC1      BC2

      1    681.2400   .37656E+04   .98016E+03   .00955   .99996
      2    694.6743   .39928E+04   .99949E+03   .01206   .99994
      3    712.2640   .43039E+04   .10248E+04   .01230   .99994
      4    732.4712   .46806E+04   .10539E+04   .01189   .99995
      5    746.5780   .49563E+04   .10742E+04   .01317   .99994
      6    789.3919   .58589E+04   .11358E+04   .04492   .99982
      7    832.2855   .68668E+04   .11975E+04   .12990   .99951
      8    908.7804   .89395E+04   .13075E+04   .11800   .99959
      9   1030.3114   .13027E+05   .14824E+04   .03855   .99988
     10   1339.2693   .28611E+05   .19269E+04   .15092   .99962
     11   1425.8530   .34527E+05   .20515E+04   .27383   .99934
     12   1536.8776   .43237E+05   .22112E+04   .13448   .99969
     13   2189.3298   .12499E+06   .31500E+04   .01900   .99997
     14   2211.6252   .12885E+06   .31821E+04   .01939   .99997
     15   2243.4470   .13449E+06   .32278E+04   .02005   .99997
     16   2423.3372   .16950E+06   .34867E+04   .04879   .99993
     17   2511.6924   .18873E+06   .36138E+04   .05423   .99992
     18   2666.2615   .22576E+06   .38362E+04   .29165   .99960
     19  15384.6104   .43370E+08   .22135E+05   .00000  1.00000
     20      0.0000   .00000E+00   .00000E+00   .00000  0.00000                 
     21  15384.6104   .43370E+08   .22135E+05   .00000  1.00000
     22   2561.4983   .20018E+06   .36854E+04   .62864   .99911
     23   1482.2567   .38789E+05   .21327E+04   .59339   .99861
     24    932.3574   .96534E+04   .13415E+04   .38284   .99869
     25    832.7332   .68778E+04   .11981E+04   .20258   .99923

GOES-11 Compared To Other GOES Shortwave Sounder Channels 13 & 15...

The GOES-8/9/10/10n/11 Channel 13 spectral response functions with and without the calculated HIS brightness temperature spectrum. Note that GOES-10n represents the updated spectral response function for GOES-10. The GOES-8/9/10/10n/11 Channel 15 spectral response functions with and without the calculated HIS brightness temperature spectrum.

GOES-11 visible data...

The GOES-/8/9/10/11 imager spectral response functions for channel 1 (visible). Note that GOES-11 continues the trend that has the spectral response moving toward higher wavelengths.

The forward model sensitivity to spectral response (SR) functions....

The calculated brightness temperatures for the 18 sounder channels (1-18) and 4 imager channels (22-25) on GOES-8, GOES-9, GOES-10, and GOES-11 using sounder spectral response functions (PLOD forward model) appear in this table.

Sounder Brightness Temperature Difference Plot. Note the large change in channels 13 and 15.
Imager Brightness Temperature Difference Plot.

The Sounder spectral response (SR) functions....

The Imager spectral response (SR) functions...

Weighting Functions...