General Requirement

ABS/HES will be an infrared Michelson interferometer or grating Atmospheric Infrared Sounder (AIRS) like sounder. The figure shows the spectral coverage of the current GOES sounder bands, 3-waveband ABS/HES (ABS prime in the figure) and 2-waveband GIFTS spectra. ABS/HES radiance measurements, at varying spectral resolutions, can be converted into atmospheric temperature, moisture and ozone profiles. ABS/HES spectral resolution will resole individual carbon dioxide absorption lines and should provide the high vertical resolution soundings with the required accuracy.

ABS/HES will scan the region within 62 degrees local zenith angle within one hour (see Figure) although only scan half of the region of overlap between the eastern and western satellites, nominally at 105W. The scan area shall be selectable to offer flexible scan scenarios. This ranges from meso-scale areas (1000 by 1000 km) through the size of the full disk.

Sounder Comparison (GOES-Current to HES-req)
Current Requirement
Coverage Rate CONUS/hr Sounding Disk/hr
Horizontal Sampling Distance 10 km 10 km
Horizontal Individual Sounding 30 - 50 km 10 km
Vertical Resolution ~3 km 1 km
Temperature Accuracy 2 deg. K 1 deg. K
Relative Humidity Accuracy 20% 10%

HES Task - Disk Sounding (HES-DS)

  1. Provide vertical moisture and temperature information, and other environmental data that will be used by NOAA and other public and private agencies to produce routine meteorological analyses and forecasts
  2. Provide data that may be used to extend knowledge and understanding of the atmosphere and its processes in order to  improve short/long-term weather forecasts.
    • Spatial Resolution
      IR: Threshold=10 km, Goal=2 km. Vis: Threshold=1.0 km, Goal= 0.5 km
    • Coverage rate (Threshold)
      62 degree LZA / hour at 10 km resolution. Coverage area must be flexible and selectable.
      Expected scan times for the DS task sensor emissive bands (HES bands 1-3)
      Coverage Region Coverage Area (km2) GSR 
      (Hz)      		 GSD
      (km)      		 Within Frame Scan Efficiency Coverage Time
      Full Disk 1.00E+08 300 10 0.6 1 hr 32.6 min
      62-degree LZA 7.00E+07 300 10 0.65 0 hr 59.8 min
      CONUS 1.50E+07 300 10 0.9 0 hr 9.3 min
      Mesoscale 1.00E+06 300 10 0.8 0 hr 0.7 min
      Coastal Water 2.40E+06 300 10 0.95 0 hr 1.4 min
    • Spectral Coverage: Three specific examples of coverage have been defined.
      15 um CO2 band for temperature, clear windows from 13 um and extending past the ozone band at 9.6 um to 8.3 um and either side of the 6 um H2O band.
      More temperature: Coverage of 4.7 um to 4.4 um and goal coverage of 4.7 um to 3.7 um. and Visible: 0.52-0.7 um
      Sounding Sensor(s) Threshold Bands
      Band HES Band Number Spectral Range (cm-1) spectral Range (micron) Band Continuity
      LWIR 1 650 - 1200 15.38 - 8.33 Contiguous
      MWIR (option 1) 2 1650 - 2150 6.06 - 4.65 Contiguous
      MWIR (option 2) 2 1210 - 1740 8.26 - 5.74 Contiguous
      SWIR 3 2150 - 2250 4.65 - 4.44 Contiguous
      VIS 4 NA 0.52 - 0.70 Contiguous

      Note: As a goal, the sounding task sensor(s) SWIR contiguous spectral range (HES band 3) should be 2150 - 2720 cm -1(4.65 - 3.68 microns).

    • Spectral resolution
      • 15 um CO2 band: 0.6 cm-1,
      • Windows: 0.6 - 1.0 cm-1,
      • Ozone: 1 cm-1,
      • H2O: 1 - 2 cm-1,
      • near 4 um: 2.5 cm-1 and
      • Visible: 0.18 um
      Sounding Sensor(s) Spectral Resolution
      Band HES Band Number Spectral Resolution (cm-1) spectral Resolution (micron)
      LWIR 1 0.625 TBS
      MWIR (option 1) 2 1.25 TBS
      MWIR (option 2) 2 1.25 TBS
      SWIR 3 2.5 TBS
      VIS 4 NA 0.18
      Sounding Sensor(s) Goal Spectral Resolution
      Band HES Band Number Spectral Resolution (cm-1) spectral Resolution (micron)
      LWIR 1 0.625 TBS
      MWIR (option 1) 2 0.625 TBS
      MWIR (option 2) 2 0.625 TBS
      SWIR 3 0.625 TBS
    • radiometric resolution

HES Task - Severe Weather / Mesoscale (HES-SW/M)

  1. Provide environmental data that can be used to expand knowledge of mesoscale and synoptic scale storm development and provide data that may be used to help in forecasting severe weather events.
  2. Backup mode in the event of a GOES-R ABI failure (both).
    • Spatial Resolution
      IR: Threshold=4 km, Goal=2 km. Vis: Threshold=1.0 km, Goal= 0.5 km
    • Coverage rate
      1000 km x 1000 km (locations vary) in 4.4 minutes. Coverage area must be flexible and selectable.
      Expected scan times for the DS task sensor emissive bands (HES bands 1-3)
      Coverage Region Coverage Area (km2) GSR 
      (Hz)      		 GSD
      (km)      		 Within Frame Scan Efficiency Coverage Time
      Full Disk 1.00E+08 300 4 0.6 9 hr 38.7 min
      62-degree LZA 7.00E+07 300 4 0.65 6 hr 46.0 min
      CONUS 1.50E+07 300 4 0.9 0 hr 57.9 min
      Mesoscale 1.00E+06 300 4 0.8 0 hr  4.3 min
      Coastal Water 2.40E+06 300 4 0.95 0 hr 8.8 min
    • Spectral coverage
      Specific examples are cited in the MRD, same as HES-DS
    • Spectral resolution:
      • 15 um CO2 band: 0.6 cm-1,
      • Windows: 0.6-1.0 cm-1,
      • Ozone: 1 cm-1,
      • H2O: 1-2 cm-1,
      • near 4 um: 2.5 cm-1and
      • Visible: 0.18 um

HES balance of temporal (30 min). spectral (0.5 cm-1), spatial (2-10 km), and radiometric (0.1 K) capabilities will

  • depict water vapor as never before by identifying small scale features of moisture vertically and horizontally in the atmosphere
  • track atmospheric motions much better by discriminating more levels of motion and assigning heights more accurately
  • characterize life cycle of clouds (cradle to grave) and distinguish between ice and water cloud
  • measure surface temperatures (land and sea) by accounting for emissivity effects
  • distinguish atmospheric constituents with improved certainty; these include volcanic ash, ozone, and possibly other trace gases

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