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MOD07_L2 (Atmosphere Profile Product)
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Format and Content
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QA Information
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Format and Content

File Format Basics

MOD07_L2 product files are stored in Hierarchical Data Format (HDF). HDF is a multi-object file format for sharing scientific data in multi-platform distributed environments. Each of the gridded parameters listed below is stored as a Scientific Data Set (SDS) within the HDF file.

The values stored in the SDS (other then the geolocation arrays) are short integer values in order to save storage space. To calculate the real data value, the scale_factor and the add_offset are needed to apply to the stored value. These are local attributes attached to each SDS. The following equation should be used to get to the real value:

value = scale_factor * (stored_value - add_offset)

Regarding to the quality assurance of the MOD07 products (derived from 5 x 5 pixels), there are either have sufficient data (e.g. at least 5 out of 25 pixels defined as confident clear) and the "Best Quality Data" retrievals are produced or the retrievals are flagged missing. The MOD07 retrievals are thus considered to be best quality.

All SDS's are stored at 5-kilometer pixel resolution. The Cloud Mask SDS, derived from the 1-km MOD35_L2 Cloud Mask parameter, is remapped to 5-km resolution, by using only the center 1-km pixel in the 5x5 pixel retreival array.




MOD07_L2 Dimension List

  1. Cell_Along_Swath = 406 (typical)
  2. Cell_Across_Swath = 270 (typical)
  3. Band_Number = 15
  4. Pressure_Level = 20
  5. Output_Parameter = 10
  6. Water_Vapor_QA_Bytes = 5



MOD07_L2 Scientific Data Set (SDS) List

    Geolocation and Time Parameters

  1. Latitude
      Description: Geodetic Latitude
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: -90 to +90 degrees north
  2. Longitude
      Description: Geodetic Longitude
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: -180 to +180 degrees east
  3. Scan_Start_Time
      Description: International Atomic Time at Start of Scan replicated across the Swath
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0.0 to 3.1558E+9 seconds since 1 January 1993 00:00:00

    Solar and Viewing Geometry Parameters

  4. Solar_Zenith
      Description: Solar Zenith Angle, Cell to Sun
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to +180 degrees
  5. Solar_Azimuth
      Description: Solar Azimuth Angle, Cell to Sun
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: -180 to +180 degrees
  6. Sensor_Zenith
      Description: Sensor Zenith Angle, Cell to Sensor
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to 180 degrees
  7. Sensor_Azimuth
      Description: Sensor Azimuth Angle, Cell to Sensor
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: -180 to 180 degrees

    Science Parameters

  8. Brightness_Temperature
      Description: Brightness Temperature
      Dimensions: (Band_Number, Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 150 to 350 K

  9. Skin_Temperature
      Description: Surface_Temperature
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 150 to 350 K

  10. Surface_Pressure
      Description: Surface_Pressure
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 800 to 1100 hPa

  11. Surface_Elevation
      Description: Surface_Elevation
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: -400 to 8840 meters

  12. Processing_Flag
      Description: Processing_Flag
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: byte array

  13. Tropopause_Height
      Description: Tropopause_Height
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 1 to 1100 hPa

  14. Guess_Temperature_Profile
      Description: Guess_Temperature_Profile
      Dimensions: (Pressure_Level, Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 150 to 350 K

  15. Guess_Moisture_Profile
      Description: Guess Dew Point Temperature Profile
      Dimensions: (Pressure_Level, Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 150 to 350 K

  16. Retrieved_Temperature_Profile
      Description: Retrieved Temperature Profile
      Dimensions: (Pressure_Level, Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 150 to 350 K

  17. Retrieved_Moisture_Profile
      Description: Retrieved Dew Point Temperature Profile
      Dimensions: (Pressure_Level, Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 150 to 350 K

  18. Retrieved_Height_Profile
      Description: Retrieved Geopotential Height Profile
      Dimensions: (Pressure_Level, Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to 65000 meters

  19. Total_Ozone
      Description: Total Ozone Burden
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to 500 Dobson units

  20. Total_Totals
      Description: Total Totals
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to 80 K

  21. Lifted_Index
      Description: Lifted Index
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: -20 to 40 K

  22. K_Index
      Description: K Index
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 268 to 340 K

  23. Water_Vapor
      Description: Total Column Precipitable Water Vapor - IR Retrieval
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to 20 cm

  24. Water_Vapor_Direct
      Description: Total Column Precipitable Water Vapor - Direct IR Retrieval
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to 20 cm

  25. Water_Vapor_Low
      Description: Precipitable Water Vapor Low - IR Retrieval
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to 20 cm

  26. Water_Vapor_High
      Description: Precipitable Water Vapor High - IR Retrieval
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: 0 to 20 cm

    Quality Assurance

  27. Quality_Assurance
      Description: Quality Assurance Parameters
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath, Output_Parameter)
      Valid Range: bit field

  28. Quality_Assurance_Infrared
      Description: Runtime Quality Assurance Flags for Water_Vapor_Infrared
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath, Water_Vapor_QA_Bytes)
      Valid Range: bit field

    Cloud Mask

  29. Cloud_Mask
      Description: MODIS Cloud Mask , First Byte
      Dimensions: (Cell_Along_Swath, Cell_Across_Swath)
      Valid Range: bit field




MOD07_L2 VData (Tables) List

  1. Band_Number
      Description: MODIS Band Number
      Dimensions: (Band_Number)
      Data Values: 20, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36

  2. Pressure_Level
      Description: Pressure Levels of Profiles
      Dimensions: (Band_Number)
      Data Values: 05., 10., 20., 30., 50., 70., 100., 150., 200., 250., 300., 400., 500., 620., 700., 780., 850., 920., 950., 1000.
      Units: hPa



Cloud_Mask Bit-Field Interpretation

The Cloud_Mask SDS is copied from a portion of the complete MODIS Cloud Mask SDS in the MOD35_L2 Product. The 1-km cloud mask is remapped to the 5-km grid by using only the center 1km pixel in the 5x5 pixel retreival array. Individual bits or groups of bits in the mask are set to denote various cloud conditions and characteristics for that pixel.

All bit and byte numbering, in the table below, will start with 0.

Cloud_Mask Bit-Field Interpretation
Byte #0
(Cloud Mask & Processing Path Flags)
Bits Field Description Bit Interpretation Key
0 Cloud Mask Flag 0 = Not Determined
1 = Determined
1-2 Unobstructed FOV Quality Flag 0 = Confident Cloudy
1 = Probably Cloudy
2 = Probably Clear
3 = Confident Clear
3 Day/Night Flag 0 = Night
1 = Day
4 Sunglint Flag 0 = Yes
1 = No
5 Snow/Ice Background Flag 0 = Yes
1 = No
6-7 Land/Water Background Flag 0=Water
1=Coastal
2=Desert
3=Land



Quality_Assurance Bit-Field Interpretation

Each pixel in the Quality_Assurance SDS is assigned a 10 byte (80 bit) array. Individual bits or groups of bits are set to denote various quality run-time characteristics for that pixel.

All bit and byte numbering, in the table below, will start with 0.

Quality_Assurance Bit-Field Interpretation
Byte #0
Bits Field Description Bit Interpretation Key
0 Retrieved Temperature Profile QA 0 = Not Useful
1 = Useful
1-2 Retrieved Temperature Profile Confidence QA 0 = Fill (Bad or Cloudy)
1 = Best Quality
2 = not currently used
3 = not currently used
3 (spare) n/a
4 Retrieved Moisture Profile QA 0 = Not Useful
1 = Useful
5-6 Retrieved Moisture Profile Confidence QA 0 = Fill (Bad or Cloudy)
1 = Best Quality
2 = not currently used
3 = not currently used
7 (spare) n/a
Byte #1
Bits Field Description Bit Interpretation Key
0 Total Ozone Burden QA 0 = Not Useful
1 = Useful
1-2 Total Ozone Burden Confidence QA 0 = Fill (Bad or Cloudy)
1 = Best Quality
2 = not currently used
3 = not currently used
3 (spare) n/a
4 Lifted Index Stability QA 0 = Not Useful
1 = Useful
5-6 Lifted Index Stability Confidence QA 0 = Fill (Bad or Cloudy)
1 = Best Quality
2 = not currently used
3 = not currently used
7 (spare) n/a
Byte #2
Bits Field Description Bit Interpretation Key
0 K Index Stability QA 0 = Not Useful
1 = Useful
1-2 K Index Stability Confidence QA 0 = Fill (Bad or Cloudy)
1 = Best Quality
2 = not currently used
3 = not currently used
3 (spare) n/a
4 Total Totals Stability QA 0 = Not Useful
1 = Useful
5-6 Total Totals Stability Confidence QA 0 = Fill (Bad or Cloudy)
1 = Best Quality
2 = not currently used
3 = not currently used
7 (spare) n/a
Byte #3
Bits Field Description Bit Interpretation Key
0-7 Number of Cloudy Pixels within 5x5 km box valid range: 0 to 25
Byte #4
Bits Field Description Bit Interpretation Key
0-7 Number of Clear Pixels within 5x5 km box valid range: 0 to 25
Byte #5
Bits Field Description Bit Interpretation Key
0-7 Number of Missing Pixels within 5x5 km box valid range: 0 to 25
Byte #6
Bits Field Description Bit Interpretation Key
0-1 Method of Profile Retrieval 0 = Statistical
1 = Physical
2 = Other
3 = No Retrieval
2-3 Method of Ozone Retrieval 0 = RTE Perturbation
1 = Upper and Lower Stratospheric Ozone Method
2 = Other
3 = No Retrieval
4-7 (spares) n/a
Byte #7
Bits Field Description Bit Interpretation Key
0-1 Guess Moisture Profile Source 0 = NCEP
1 = DAO
2 = AIRS/AMSU
3 = Not Used
2-3 Guess Temperature Profile Source 0 = NCEP
1 = DAO
2 = AIRS/AMSU
3 = Not Used
4-5 Surface Temperature over Land 0 = NCEP
1 = DAO
2 = Other
3 = Not Used
6-7 Surface Temperature over Ocean 0 = Reynolds blended
1 = DAO
2 = Other
Byte #8
Bits Field Description Bit Interpretation Key
0-1 Surface Pressure 0 = NCEP
1 = DAO
2 = Other
3 = Not Used
2-3 Ocean Profile First Guess 0 = TOMS
1 = TOVS
2 = DAO
3 = Other
4-7 (spares) n/a
Byte #9
Bits Field Description Bit Interpretation Key
0-7 (spares) n/a



Quality_Assurance_Infrared Bit-Field Interpretation

Each pixel in the Quality_Assurance_Infrared SDS is assigned a 5 byte (40 bit) array. Individual bits or groups of bits are set to denote various quality run-time characteristics for that pixel.

All bit and byte numbering, in the table below, will start with 0.

Quality_Assurance_Infrared Bit-Field Interpretation
Byte #0
Bits Field Description Bit Interpretation Key
0 IR Water Vapor QA 0 = Not Useful
1 = Useful
1-2 IR Water Vapor Confidence QA 0 = Fill (Bad or Cloudy)
1 = Best Quality
2 = not currently used
3 = not currently used
3-7 (spares) n/a
Byte #1
Bits Field Description Bit Interpretation Key
0-7 Number of Cloudy Pixels within 5x5 km box valid range: 0 to 25
Byte #2
Bits Field Description Bit Interpretation Key
0-7 Number of Clear Pixels within 5x5 km box valid range: 0 to 25
Byte #3
Bits Field Description Bit Interpretation Key
0-7 Number of Missing Pixels within 5x5 km box valid range: 0 to 25
Byte #4
Bits Field Description Bit Interpretation Key
0 IR Water Vapor Retrieval Method Used 0 = Split Window (11-12)
1 = Moisture Profile Integration
2 = Other
3 = No Retrieval
1-7 (spares) n/a



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