ECOSTRESS Overview


Introduction

The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) is aboard the International Space Station (ISS) and measures the temperature of plants to better understand how much water plants need and how they respond to stress. ECOSTRESS was launched to the ISS on June 29, 2018. It has a viewing swath width of around 384 km and views the surface of the Earth from 53.6° N latitude to 53.6° S latitude with variable revisit times, dependent on the orbit of the ISS. Images are acquired over the conterminous U.S. (CONUS), over key biomes around the world, and in European and South Asian agricultural zones and selected FLUXNET validation sites. ECOSTRESS uses a multispectral thermal infrared radiometer to capture radiance of the Earth’s surface in five spectral bands with one shortwave infrared band, and it acquires data at ~70 m spatial resolution. On May 15, 2019, following mass storage unit anomalies, a new data acquisition strategy was implemented for acquiring three of the spectral bands. Learn more on the ECOSTRESS website.

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ECOSTRESS Naming Conventions

ECOSTRESS Filenames

ECOSTRESS filenames (i.e., the local granule ID) follow a naming convention which gives useful information regarding the specific product.

In this example of a grid product, the filename ECOv002_L2G_LSTE_24423_017_20221026T195702_0710_01.h5 indicates:

  • ECO – Sensor
  • v002 – Product Version
  • L2G – Processing Level and Type (Blank for Swath or G = Grid)
  • LSTE – Geophysical Parameter
  • 24423 – Orbit Number
  • 017 – Scene ID
  • 20221026 – Date of Acquisition (YYYYMMDD)
  • T195702 – Time of Acquisition (HHMMSS) (in UTC)
  • 0710 – Build ID of software that generated product, Major+Minor (2+2 digits)
  • 01 – Product Iteration Number
  • .h5 – Data Format for Grid or Swath

In this example of a tile product, the filename ECOv002_L2T_LSTE_24498_003_10TGN_20221031T150810_0710_01_LST.tif indicates:

  • ECO – Sensor
  • v002 – Product Version
  • L2T – Processing Level and Type (T = Tile)
  • LSTE – Geophysical Parameter
  • 24498 – Orbit Number
  • 003 – Scene ID
  • 10TGN – Military Grid Reference System (MGRS) Tile ID
  • 20221031 – Date of Acquisition (YYYYMMDD)
  • T150810 – Time of Acquisition (HHMMSS) (in UTC)
  • 0710 – Build ID of software that generated product, Major+Minor (2+2 digits)
  • 01 – Product Iteration Number
  • LST – Layer/band Name (each layer is a separate file)
  • .tif – Data Format for Tile

ECOSTRESS Product Long Name

The ECOSTRESS Product Long Name (i.e., Collection-Level) convention provides useful information regarding all ECOSTRESS products.

Below is an example for an ECOSTRESS Level-2 product, although all ECOSTRESS Product Long Names follow the same structure.

The ECOSTRESS Tiled Land Surface Temperature and Emissivity Instantaneous L2 Global 70 m V002 collection has the following characteristics:

  • ECOSTRESS – Instrument
  • Tiled – Product Type (Swath, Gridded, or Tiled)
  • Land Surface Temperature and Emissivity – Geophysical Parameter
  • Instantaneous – Temporal Resolution
  • L2 – Processing Level
  • Global – Spatial Extent
  • 70 m – Spatial Resolution
  • V002 - Version
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ECOSTRESS Temporal and Spatial Resolution

ECOSTRESS Temporal Resolution

All ECOSTRESS products distributed from the LP DAAC are produced nominally at a daily temporal resolution. The true revisit period for a given location is variable based on the instrument’s orbital cycle aboard the ISS.

ECOSTRESS Spatial Resolution

All ECOSTRESS products are produced at 70 m resolution.

ECOSTRESS Coordinate Reference System

Swath
ECOSTRESS Level-1 (L1) and Level-2 (L2) products are produced, archived, and distributed as swath products. The ECOSTRESS Swath Geolocation Instantaneous L1B Global 70 m data product is required to georeference the corresponding swath products. Below are resources for resampling ECOSTRESS swath products into geolocated, gridded outputs.

Grid
ECOSTRESS Level-1C (L1C), Level-2 (L2), Level-3 (L3), and Level-4 (L4) products are distributed as grid products using the letter G in their level identifiers: L1CG/L2G/L3G/L4G. ECOSTRESS L1C/L2G/L3G/L4G gridded data products incorporate the latitude and longitude arrays from the ECOSTRESS Swath Geolocation Instantaneous L1B Global 70 m product to resample the swath data to a 0.0006° grid in WGS84 latitude and longitude.

Tile
ECOSTRESS L1C, L2, L3, and L4 products, except for the L2 Cloud product, are distributed as tile products using the letter T in their level identifiers: L1CG/L2T/L3T/L4T. ECOSTRESS L2T/L3T/L4T tiled data products align with the Military Grid Reference System (MGRS), and its naming convention is derived from the Universal Transverse Mercator (UTM) system. The UTM system divides the Earth’s surface into 60 vertical zones. Each UTM zone has a vertical width of 6° of longitude and horizontal width of 8° of latitude. Each UTM zone is subdivided into MGRS 110 x 110 km zones. ECOSTRESS uses a 70 m cell size with 1568 rows by 1568 columns in each tile. This allows the end user to assume that each 70 m ECOSTRESS pixel will remain in the same location at each timestep observed in analysis.

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ECOSTRESS Data Processing

ECOSTRESS Processing Levels

The LP DAAC distributes ECOSTRESS data processed to Level-1 or higher:

  • Level-1: Attitude, geolocation, and radiance products
  • Level-2: Land surface temperature and emissivity data retrieved from the Level-1 radiance data, and cloud mask products
  • Level-3: Evapotranspiration products derived from Level-2 data
  • Level-4: Evaporative stress index and water use efficiency products derived from Level-3 data

ECOSTRESS Processing Description

The ECOSTRESS mission generates swath, gridded, and tiled distributable data products. The products represent four levels of data processing, with data granules defined as an image scene. Each swath and grid image scene consists of 44 scans of the instrument mirror, each scan taking approximately 1.181 seconds, and each image scene taking approximately 52 seconds. Each image scene starts at the beginning of the first target area encountered during each orbit. Each orbit is defined as the equatorial crossing of an ascending ISS orbit. The ECOSTRESS Science Data Systems (SDS) will acquire, ingest, and store the ECOSTRESS payload and instrument telemetry and ancillary files via its interfaces with the other ground network assets. These data will be both stored for the life-of-mission as well as used for science product generation through Level-4. The SDS will generate Level-0 through Level-2 data products, as well as Level-3 and Level-4 data products using the PT-JPL algorithm. Higher level products are also generated in tiled format aligned with the MGRS tiling scheme. The ECOSTRESS SDS will deliver Level-0 through Level-4 data products to the USGS EROS Center for archival and public distribution.

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ECOSTRESS Spectral Bands

Band Emitted Range (band center,
µm)
Band Notes
1 1.660
2 8.285 Unavailable for acquisitions after May
15, 2019
3 8.785
4 9.060 Unavailable for acquisitions after May
15, 2019
5 10.522
6 12.001
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ECOSTRESS Data Format and Metadata

Swath and Grid

All metadata that describe the full content of each granule of the swath or gridded ECOSTRESS data products are stored within the explicitly named “/Metadata” Group. The metadata contain valuable information including global attributes and dataset specific attributes pertaining to the granule. Metadata are handled using the same procedures as those that are used to handle data. The contents of each Attribute that store metadata conform to one of the ECOSTRESS Types. Most metadata elements are stored as scalars. A few metadata elements are stored as arrays. The metadata for swath and gridded data products appear in a set of HDF5 Groups under the “/Metadata” Group. These HDF5 Groups contain a set of HDF5 Attributes.

ECOSTRESS standards incorporate additional metadata that describe each HDF5 dataset within the HDF5 file. Each of these metadata elements appear in an HDF5 Attribute that is directly associated with the HDF5 dataset. Wherever possible, these HDF5 Attributes employ names that conform to the Climate and Forecast (CF) conventions. These attributes contain specific SDS information such as the data range and applicable scaling factors for the data. The LP DAAC data products page provides these details within a concise document for each of the products. Additionally, ECOSTRESS granules contain external ECS metadata. The ECS (generated by the EOSDIS Core System) .met file is the external metadata file in XML format, which is delivered to the user along with the ECOSTRESS product. It provides a subset of the HDF metadata.

Tile

The ECOSTRESS Version 2 tiled products are distributed using the Cloud-Optimized GeoTIFF (COG) format. Each dataset layer is distributed as a separate file. Tiled granules have two sources of metadata: the embedded COG metadata and the external ECS (generated by the EOSDIS Core System) metadata. The COG metadata contains valuable information, including global attributes and dataset specific attributes pertaining to the granule. The ECS .met file is the external metadata file in JSON format.

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ECOSTRESS Tools and Services

Data access options such as Data Pool, NASA Earthdata Search, AppEEARS, and USGS EarthExplorer can be found under Tools.

Swath and Grid

ECOSTRESS swath and gridded products are stored in the Hierarchical Data Format version 5 (HDF5). HDF5 is a general-purpose file format and programming library for storing scientific data.

Certain open-source tools and proprietary tools are available for use with ECOSTRESS HDF5 products:

Open-Source Tools

Proprietary Tools

Tile

ECOSTRESS tiled products are stored in Cloud-Optimized GeoTIFF (COG), which is aimed at being hosted on an HTTP file server, with an internal organization that enables more efficient workflows in the cloud.

The COG format also facilitates end-user analysis as a universally recognized and supported format, compatible with the following open-source and proprietary tools:

Open-Source Tools

Proprietary Tools

Additional Resources for working with ECOSTRESS data.

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