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MYD11A1 V006

10.5067/MODIS/MYD11A1.006
MODIS/Aqua Land Surface Temperature/Emissivity Daily L3 Global 1 km SIN Grid
MYD11A1

The MYD11A1 Version 6 product provides daily, per-pixel land surface temperature (LST) in a 1200 x 1200 kilometer grid. The pixel temperature value is derived from the MYD11_L2 swath product. Above 30 degrees latitude, some pixels may have multiple observations where the criteria for clear-sky are met. When this occurs, the pixel value is a result of the average of all qualifying observations. Provided along with both the day-time and night-time surface temperature bands and their quality indicator layers, are MODIS bands 31 and 32 and six observation layers. Validation at stage 2 has been achieved for all MODIS LST/Emissivity products.

Improvements/Changes from Previous Versions

  • Removed cloud-contaminated LSTs not only from level 3 LST products but also from level 2 LST products, which includes MOD11_L2.
  • Updated the coefficient look-up table (LUT) for the split-window algorithm with comprehensive regression analysis of MODIS simulation data in bands 31 and 32 over wide ranges of surface and atmospheric conditions, especially extending the upper boundary for (LST – Ts-air) in arid and semi-arid regions and increasing the overlapping between various sub-ranges in order to reduce the sensitivity of the algorithm to the uncertainties in the input data (i.e., column water vapor and air surface temperature from MxD07).
  • Made minor adjustments in the classification-based surface emissivity values, especially for bare soil and rocksland cover types.
  • Tuned the day/night algorithm by adjusting weights to improve its performance in desert regions where the incorporated split-window algorithm may not work well.
  • Generated new LST products for 8-day and monthly at 6 kilometer grids, in response to user community requests.

Collection

Characteristic Description
Temporal Granularity Daily
Temporal Extent July 2002 - Present
Spatial Extent Global
File Size ~2 MB
Coordinate System Sinusoidal
Datum N/A
File Format HDF-EOS
Geographic Dimensions 1200 km x 1200 km

 

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers 12
Columns/Rows 1200 x 1200
Pixel Size 1000 m

 

Data Layer Characteristics

SDS Name Description Units Data Type Fill Value Valid Range Scale Factor
LST_Day_1km

Day Land Surface Temperature

Kelvin 16-bit unsigned integer

0

7500 to 65535

0.02
QC_Day

Daytime LST Quality Indicators

Bit field 8-bit unsigned integer

N/A

0 to 255

N/A
Day_view_time

Local time of day observation

Hours 8-bit unsigned integer

255

0 to 240

0.1
Day_view_angl

View zenith angle of day observation

Degree 8-bit unsigned integer

255

0 to 130

N/A
LST_Night_1km

Night Land Surface Temperature

Kelvin 16-bit unsigned integer

0

7500 to 65535

0.02
QC_Night

Nighttime LST Quality indicators

Bit field 8-bit unsigned integer

N/A

0 to 255

N/A
Night_view_time

Local time of night observation

Hours 8-bit unsigned integer

255

0 to 240

0.1
Night_view_angl

View zenith angle of night observation

Degree 8-bit unsigned integer

255

0 to 130

N/A
Emis_31

Band 31 emissivity

N/A 8-bit unsigned integer

0

1 to 255

0.002
Emis_32

Band 32 emissivity

N/A 8-bit unsigned integer

0

1 to 255

0.002
Clear_day_cov

Day clear-sky coverage

N/A 16-bit unsigned integer

0

1 to 65535

0.0005
Clear_night_cov

Night clear-sky coverage

N/A 16-bit unsigned integer

0

1 to 65535

0.0005

 

 

Product Quality

The QC layer is stored in an efficient bit-encoded manner. The unpack_sds_bits executable from the LDOPE Tools is available to the user community to help parse and interpret the QC layer.

In addition to data access and transformation processes, AppEEARS also has the capability to unpack and interpret the QC layer.

The QA bit flags for the QC layer are given in the User Guide in Table 13 on page 21.

Please note that whenever the Mandatory QA flags (bits 0-1) have a value of 2 (decoded to 10) or 3 (decoded to 11), LST is not produced due to cloud effects or other reasons. Under these conditions, all remaining QA bits and SDS Layers are undefined (although bit flags display as 00).

 

Known Issues

For complete information about the MYD11A1 known issues please refer to the MODIS Land Quality Assessment website.

MYD11A1 V006 image

MYD11A1. Acquired June 21, 2003. Tile H17V05. Strait of Gibraltor.

PI Name: 
Zhengming Wan
Other Tools: 
Decommissioned: 
False