MOD11A2 v006

MODIS/Terra Land Surface Temperature/Emissivity 8-Day L3 Global 1 km SIN Grid


PI: Zhengming Wan

The MOD11A2 Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the MOD11A2 Version 6.1 data product.

Description

The MOD11A2 Version 6 product provides an average 8-day per-pixel Land Surface Temperature and Emissivity (LST&E) with a 1 kilometer (km) spatial resolution in a 1,200 by 1,200 km grid. Each pixel value in the MOD11A2 is a simple average of all the corresponding MOD11A1 LST pixels collected within that 8-day period. The 8-day compositing period was chosen because twice that period is the exact ground track repeat period of the Terra and Aqua platforms. Provided along with the daytime and nighttime surface temperature bands are associated quality control assessments, observation times, view zenith angles, and clear-sky coverages along with bands 31 and 32 emissivities from land cover types.

read more

Characteristics

Improvements/Changes from Previous Versions

  • Removed cloud-contaminated LSTs from Level 2 and Level 3 LST products.
  • Updated the coefficient look-up table (LUT) for the split-window algorithm with comprehensive regression analysis of Moderate Resolution Imaging Spectroradiometer (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. Increased the overlap between various sub-ranges to reduce the sensitivity of the algorithm to uncertainties in the input data (i.e., column water vapor and air surface temperature from MOD07).
  • Made minor adjustments in the classification-based surface emissivity values, especially for bare soil and rocks land cover types.
  • Tuned the day/night algorithm by adjusting weights to improve performance in desert regions where the incorporated split-window algorithm may not work well.
  • Generated new gridded LST&E products with a 6 km spatial resolution for 8-day (MOD11B2) and monthly (MOD11B3) intervals in response to user community requests.

Product Maturity

Validation at stage 2 has been achieved for all MODIS Land Surface Temperature and Emissivity products. Further details regarding MODIS land product validation for the MOD11 data products are available from the MODIS Land Team Validation site.

Collection and Granule

Collection

Characteristic Description
CollectionTerra MODIS
DOI10.5067/MODIS/MOD11A2.006
File Size~3.86 MB
Temporal ResolutionMulti-Day
Temporal Extent2000-02-18 to 2022-11-16
Spatial ExtentGlobal
Coordinate SystemSinusoidal
DatumN/A
File FormatHDF-EOS
Geographic Dimensions1200 km x 1200 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers12
Columns/Rows1200 x 1200
Pixel Size1000 m

Layers / Variables

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor Offset
LST_Day_1km Daytime Land Surface Temperature Kelvin 16-bit unsigned integer 0 N/A 7500 to 65535 0.02 N/A
QC_Day Daytime LST Quality Indicators Bit Field 8-bit unsigned integer N/A N/A 0 to 255 N/A N/A
Day_view_time Local time of day observation Hours 8-bit unsigned integer 255 N/A 0 to 240 0.1 N/A
Day_view_angl View zenith angle of day observation Degree 8-bit unsigned integer 255 N/A 0 to 130 N/A -65
LST_Night_1km Nighttime Land Surface Temperature Kelvin 16-bit unsigned integer 0 N/A 7500 to 65535 0.02 N/A
QC_Night Nighttime LST Quality indicators Bit Field 8-bit unsigned integer N/A N/A 0 to 255 N/A N/A
Night_view_time Local time of night observation Hours 8-bit unsigned integer 255 N/A 0 to 240 0.1 N/A
Night_view_angl View zenith angle of night observation Degree 8-bit unsigned integer 255 N/A 0 to 130 N/A -65
Emis_31 Band 31 emissivity N/A 8-bit unsigned integer 0 N/A 1 to 255 0.002 0.49
Emis_32 Band 32 emissivity N/A 8-bit unsigned integer 0 N/A 1 to 255 0.002 0.49
Clear_sky_days Day clear-sky coverage Bit Field 8-bit unsigned integer 0 N/A 1 to 255 N/A N/A
Clear_sky_nights Night clear-sky coverage Bit Field 8-bit unsigned integer 0 N/A 1 to 255 N/A N/A

Product Quality

The Quality Control (QC) layers are 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 layers.

The QA bit flags for the QC layers are provided in the User Guide in Table 13.

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).

Quality assurance information should be considered when determining the usability of data for a particular science application. The ArcGIS MODIS-VIIRS Python Toolbox contains tools capable of decoding quality data layers while producing thematic quality raster files for each quality attribute.

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

Known Issues

Production of V6 Terra MODIS Land Surface Temperature and Emissivity (LST&E) data products was discontinued on November 16, 2022, due to significant loss of data retrieval following the Constellation Exit Maneuvers.

For complete information about the MOD11A2 known issues please refer to the MODIS Land Quality Assessment website.


About the image

Terra MODIS land surface temperature data from the MOD11A2 product over Tibet, July 4 - 11, 2018.

View full-size image

Documentation

User Guide
Algorithm Theoretical Basis Document (ATBD)
File Specification

Using the Data

Access Data

Citation

DOI: 10.5067/MODIS/MOD11A2.006