ECO_L1B_RAD v002

ECOSTRESS Swath Top of Atmosphere Calibrated Radiance Instantaneous L1B Global 70 m


PI: Simon Hook, Mike Smyth, Tom Logan, William Johnson

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 globally between 52° N and 52° S latitudes. A map of the acquisition coverage can be found in figure 2 on the ECOSTRESS website.

The ECOSTRESS Swath Top of Atmosphere Calibrated Radiance Instantaneous L1B Global 70 m (ECO_L1B_RAD) Version 2 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) and 90 m at the edge of the swath. The ECO_L1B_RAD data product is provided as swath data and does not contain geolocation information. The corresponding ECO_L1B_GEO data product is required to georeference the ECO_L1B_RAD data product. The geographic coverage of acquisitions for the ECO_L1B_RAD Version 2 data product extends to areas outside of those indicated on the coverage map.

The ECO_L1B_RAD Version 2 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 distributed in HDF5 format.

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Characteristics

Improvements/Changes from Previous Versions

A radiance calibration has been applied to correct the ~1K cold bias that has been observed in previous studies. These values are described in Section 3 of the User Guide.

Collection and Granule

Collection

Characteristic Description
CollectionECOSTRESS
DOI10.5067/ECOSTRESS/ECO_L1B_RAD.002
File Size~300 MB
Temporal ResolutionVaries
Temporal Extent2018-07-09 to Present
Spatial ExtentGlobal (+/- 52 degrees latitude)
Coordinate SystemN/A
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 / Variables

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
radiance_1 TIR 8.285 microns¹ 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 microns¹ 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 Deprecated Counts Correction¹ 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 4294967295 N/A 0 to 1749247 N/A
line_start_time_j2000 J2000² time of first pixel in line Seconds 64-bit floating point N/A N/A N/A N/A

¹For data acquired after May 15, 2019, this is fill data only.

²See the Product Specification Document (PSD) Section 2.4.1 for more information on J2000.

Radiance 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 ECO_L1B_RAD Version 2 data product is provided in Section 3.3 of the User Guide.

Known Issues

  • Cannot perform spatial query on ECO_L1B_RAD in NASA Earthdata Search: ECO_L1B_RAD does not contain spatial attributes, so granules cannot be searched by geographic location. Users should search for ECO_L1B_RAD data products by orbit number instead.

  • Data acquisition gap: 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). This approach was implemented from May 15, 2019, through April 28, 2023.

  • Data acquisition gap: From February 8 to February 16, 2020, an ECOSTRESS instrument issue resulted in a data anomaly that created striping in band 4 (10.5 micron). These data products have been reprocessed and are available for download. No ECOSTRESS data were acquired on February 17, 2020, due to the instrument being in SAFEHOLD. Data acquired following the anomaly have not been affected.

  • 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.

  • Data acquisition: ECOSTRESS has now successfully returned to 5-band mode after being in 3-band mode since 2019. This feature was successfully enabled following a Data Processing Unit firmware update (version 4.1) to the payload on April 28, 2023. To better balance contiguous science data scene variables, 3-band collection is currently being interleaved with 5-band acquisitions over the orbital day/night periods.


About the image

ECOSTRESS Top of Atmosphere Calibrated Radiance bands 2-4-5 data from the ECO_L1B_RAD product over California, United States, acquired on November 29, 2022.

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Documentation

User Guide
Calibration Algorithm Theoretical Basis Document (ATBD)
Geolocation Algorithm Theoretical Basis Document (ATBD)
Product Specification Document (PSD)
Radiance Algorithm Specification Document (ASD)
Geolocation Algorithm Specification Document (ASD)
Earthdata Search Quick Guide

Using the Data

Access Data

Citation

DOI: 10.5067/ECOSTRESS/ECO_L1B_RAD.002