ECO1BRAD v001

ECOSTRESS At-sensor Calibrated Radiance Daily L1B Global 70 m


PI: Simon Hook

Description

The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) mission measures the temperature of plants to better understand how much water plants need and how they respond to stress. ECOSTRESS is attached to the International Space Station (ISS) and collects data over the conterminous United States (CONUS) as well as key biomes and agricultural zones around the world and selected FLUXNET validation sites. A map of the acquisition coverage can be found on the ECOSTRESS website.

The ECO1BRAD Version 1 data product provides at-sensor calibrated radiance values retrieved for five thermal infrared (TIR) bands operating between 8 and 12.5 µm. Additionally, the digital numbers (DN) for the shortwave infrared (SWIR) band are provided. The TIR bands are spatially co-registered to produce a variable spatial resolution between 70 meters (m) to 90 m at the edge of the swath. The ECO1BRAD data product is provided as swath data and does not contain geolocation information. The corresponding ECO1BGEO data product is required to georeference the ECO1BRAD data product. The geographic coverage of acquisitions for the ECO1BRAD Version 1 data product extends to areas outside of those indicated on the coverage map. However, corresponding higher-level products over these areas are not available at this time.

The ECO1BRAD Version 1 data product contains layers of radiance values for the five TIR bands, DN values for the SWIR band, associated data quality indicators, and ancillary data. For acquisitions after May 15, 2019, data products contain data values for the 8.785 μm, 10.522 μm, and 12.001 μm (TIR) bands only. The 1.6 μm (SWIR), 8.285 μm (TIR), and 9.060 μm (TIR) bands contain fill values to accommodate direct streaming of data from the ISS as mentioned in the Known Issues section.

Characteristics

Collection and Granule

Collection

Characteristic Description
CollectionECOSTRESS
DOI10.5067/ECOSTRESS/ECO1BRAD.001
File Size~800 MB
Temporal ResolutionVaries
Temporal Extent2018-07-09 to Present
Spatial ExtentCONUS, key biomes/agricultural zones, selected FLUXNET sites
Coordinate SystemNone (Swath)
DatumN/A
File FormatHDF5
Geographic Dimensions400 km x 400 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers13
Columns/Rows5400 x 5632
Pixel Size70 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
radiance_1 TIR 8.285 microns W/m²/sr/μm 32-bit floating point -9999 to -9997 N/A N/A N/A
radiance_2 TIR 8.785 microns W/m²/sr/μm 32-bit floating point -9999 to -9997 N/A N/A N/A
radiance_3 TIR 9.060 microns W/m²/sr/μm 32-bit floating point -9999 to -9997 N/A N/A N/A
radiance_4 TIR 10.522 microns W/m²/sr/μm 32-bit floating point -9999 to -9997 N/A N/A N/A
radiance_5 TIR 12.001 microns W/m²/sr/μm 32-bit floating point -9999 to -9997 N/A N/A N/A
data_quality_1 Data Quality Indicators for radiance_1 N/A 8-bit signed integer N/A N/A 0 to 4 N/A
data_quality_2 Data Quality Indicators for radiance_2 N/A 8-bit signed integer N/A N/A 0 to 4 N/A
data_quality_3 Data Quality Indicators for radiance_3 N/A 8-bit signed integer N/A N/A 0 to 4 N/A
data_quality_4 Data Quality Indicators for radiance_4 N/A 8-bit signed integer N/A N/A 0 to 4 N/A
data_quality_5 Data Quality Indicators for radiance_5 N/A 8-bit signed integer N/A N/A 0 to 4 N/A
swir_dn Uncalibrated SWIR data with Dark Current subtracted N/A 16-bit signed integer -9999 to -9997 N/A N/A N/A
EncoderValue Mirror encoder value of each focal plane in each scan N/A 32-bit unsigned integer 0xffffffff N/A 0 to 1749247 N/A
line_start_time_j2000 J2000 time of first pixel in line Seconds 64-bit floating point N/A N/A N/A N/A

Fill Value Classes

Value Description
-9997 Pixel not seen
-9998 Missing data due to striping (not filled in)
-9999 Missing/bad data

Data Quality Classes

Value Description
0 Good
1 Missing stripe data, filled in
2 Missing stripe data, not filled in
3 Missing/bad data
4 Not seen

Product Quality

Quality information for the ECO1BRAD Version 1 data product is provided in section 3.3 of the User Guide.

Known Issues

  • Cannot perform spatial query on ECO1BRAD in NASA Earthdata Search: ECO1BRAD does not contain spatial attributes, so granules cannot be searched by geographic location. Users should search for ECO1BRAD data products by orbit number instead.

  • Data acquisition gaps: ECOSTRESS was launched on June 29, 2018 and moved to autonomous science operations on August 20, 2018 following a successful in-orbit checkout period. On September 29, 2018, ECOSTRESS experienced an anomaly with its primary mass storage unit (MSU). ECOSTRESS has a primary and secondary MSU (A and B). On December 5, 2018, the instrument was switched to the secondary MSU and science operations resumed. On March 14, 2019, the secondary MSU experienced a similar anomaly temporarily halting science acquisitions. On May 15, 2019, a new data acquisition approach was implemented and science acquisitions resumed. To optimize the new acquisition approach TIR bands 2, 4 and 5 are being downloaded. The data products are as previously, except the bands not downloaded contain fill values (L1 radiance and L2 emissivity).

  • Missing scan data/striping features: During testing, an instrument artifact was encountered in ECOSTRESS bands 1 and 5, resulting in missing values. A machine learning algorithm has been applied to interpolate missing values. For more information on the missing scan filling techniques and outcomes, see section 3.3.2 of the User Guide.

  • Scan overlap: An overlap between ECOSTRESS scans results in a clear line overlap and repeating data. Additional information is available in section 3.2 of the User Guide.

  • Scan flipping: Improvements to the visualization of the data to compensate for instrument orientation are discussed in section 3.4 of the User Guide.

  • Cold bias: ECOSTRESS Level-1 Radiance data shows high correlation with in-situ ground measurements (R2 = 0.99 in all bands). Currently, ECOSTRESS has a cold bias of approximately 0.7 Kelvin (K), which will be corrected through calibration in future data releases.

Documentation

Using the Data

E-Learning

ECOSTRESS: NASA's Next-Generation Mission to Measure Evapotranspiration from the ISS

Tools

Citation

DOI: 10.5067/ECOSTRESS/ECO1BRAD.001

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