AndreaBozzo/ceres-open-data-index huggingface dataset:
MODIS/Terra+Aqua Photosynthetically Active Radiation Daily/3-Hour L3 Global 5km SIN Grid V006

MCD18A2 Version 6 was decommissioned on October 28, 2022. Users are encouraged to use the [MCD18A2 Version 6.2 data product](https://doi.org/10.5067/MODIS/MCD18A2.062). The MCD18A2 Version 6 is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Photosynthetically Active Radiation (PAR) gridded Level 3 product produced daily at 5 kilometer pixel resolution with estimates of PAR every 3 hours. PAR is incident solar radiation in the visible spectrum (400-700 nanometers) and is an important variable in land-surface models that address a variety of scientific and application issues. The MCD18 products are based on a prototyping algorithm that uses multi-temporal signatures of MODIS data to derive surface reflectance and then calculate incident PAR using the look-up table (LUT) approach. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. Global PAR products are generated from MODIS and geostationary satellite data. Additional details regarding the methodology used to create the data are available in the Algorithm Theoretical Basis Document (ATBD). Provided in the MOD18A2 product are layers for instantaneous PAR array for each individual MODIS overpass and 3-hour PAR array along with a View Zenith Angle layer. Known Issues * For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=TerraAqua&as=6).

Tags: earth-science-surface-radiative-properties-land-surface-albedo, earth-science-surface-radiative-properties-land-surface-anisotropy, earth-science-surface-radiative-properties-land-surface-reflectance
Organization: National Aeronautics and Space Administration
NASA Shuttle Radar Topography Mission Global 3 arc second sub-sampled V003

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of NASA Making Earth System Data Records for Use in Research Environments ([MEaSUREs](https://earthdata.nasa.gov/about/competitive-programs/measures )) SRTM, which includes the global 3 arc second (~90 meter) sub-sampled product. The 3 arc second data was derived from the 1 arc second using sampling methods. (See Figure 3 in the User Guide) The NASA SRTM data sets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA - previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. This collaboration aims to generate a near-global digital elevation model (DEM) of Earth using radar interferometry. SRTM was the primary (and virtually only) payload on the STS-99 mission of the Space Shuttle Endeavour, which launched February 11, 2000 and flew for 11 days. The SRTMGL3 data were sub-sampled from [SRTM1GL](https://doi.org/10.5067/MEaSUREs/SRTM/SRTMGL1.003) data that fall within that tile. These elevation files use the extension ".HGT", meaning height (such as N37W105.SRTMGL3S.HGT). The primary goal of creating the Version 3 data was to eliminate gaps, or voids, that were present in earlier versions of SRTM data. In areas with limited data, existing topographical data were used to supplement the SRTM data to fill the voids. The source of each elevation pixel is identified in the corresponding [SRTMGL3N](https://doi.org/10.5067/MEaSUREs/SRTM/SRTMGL3N.003) product (such as N37W105.SRTMGL3N.NUM). The SRTM swaths extended from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km), creating swaths ~225 km wide, and consisted of all land between 60° N and 56° S latitude to account for 80% of Earth's total landmass. Known Issues * Known issues in the NASA SRTM are described in the following publication: * Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249 Improvements/Changes from Previous Version * Voids in the Version 3.0 products have been filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED).

Tags: earth-science-radar-spectral-engineering-radar-imagery, earth-science-topography-land-surface-terrain-elevation, earth-science-topography-land-surface-terrain-elevation-digital-elevation-terrain-model-dem
Organization: National Aeronautics and Space Administration
NASA Shuttle Radar Topography Mission Combined Image Data Set V003

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of NASA Making Earth System Data Records for Use in Research Environments ([MEaSUREs](https://earthdata.nasa.gov/about/competitive-programs/measures )) SRTM, which includes the global 1 arc second (~30 meter) combined (merged) image data product. (See User Guide Section 2.2.2) The combined image data set contains mosaicked one degree by one degree images/tiles of uncalibrated radar brightness values at 1 arc second. To create a smooth mosaic image, each pixel in an output is an average of all the image pixels for a location. Pixels with a value of zero (voids) were not counted. Because SRTM imaged a given location with two like-polarization channels (VV = vertical transmit and vertical receive, and HH = horizontal transmit and horizontal receive) and at a variety of look and azimuth angles, the quantitative scattering information was lost in the pursuit of a smoother image product unlike the SRTM swath image product [SRTMIMGR](https://doi.org/10.5067/MEaSUREs/SRTM/SRTMIMGR.003), which preserved the quantitative scattering information. The NASA SRTM data sets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA - previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. This collaboration aims to generate a near-global digital elevation model (DEM) of Earth using radar interferometry. SRTM was the primary (and virtually only) payload on the STS-99 mission of the Space Shuttle Endeavour, which launched February 11, 2000 and flew for 11 days. The SRTM swaths extended from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km), creating swaths ~225 km wide, and consisted of all land between 60° N and 56° S latitude to account for 80% of Earth's total landmass. Known Issues * Known issues in the NASA SRTM are described in the following publication: * Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249 Improvements/Changes from Previous Version * Version 3.0 products are filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED).

Tags: earth-science-radar-spectral-engineering-radar-imagery, earth-science-topography-land-surface-terrain-elevation, earth-science-topography-land-surface-terrain-elevation-topographical-relief-maps
Organization: National Aeronautics and Space Administration
NASA Shuttle Radar Topography Mission Swath Image Data V003

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of NASA Making Earth System Data Records for Use in Research Environments ([MEaSUREs](https://earthdata.nasa.gov/about/competitive-programs/measures )) SRTM, which includes the global 1 arc second (~30 meter) swath (raw) image data product. (See User Guide Section 2.2.1) The SRTM swath image data set consists of radar image files containing brightness values, as well as quality assurance (incidence angle) files for each of four overlapping sub-swaths that passes through a 1 degree by 1 degree tile. Data from each sub-swath is included as a separate file. Some files may contain only partial data; however, every image pixel acquired by SRTM is included in this data set. The NASA SRTM data sets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA - previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. This collaboration aims to generate a near-global digital elevation model (DEM) of Earth using radar interferometry. SRTM was the primary (and virtually only) payload on the STS-99 mission of the Space Shuttle Endeavour, which launched February 11, 2000 and flew for 11 days. The SRTM swaths extended from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km), creating swaths ~225 km wide, and consisted of all land between 60° N and 56° S latitude to account for 80% of Earth's total landmass. Known Issues * Known issues in the NASA SRTM are described in the following publication: * Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249 Improvements/Changes from Previous Version * Version 3.0 products are filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED).

Tags: earth-science-radar-spectral-engineering-radar-imagery, earth-science-topography-land-surface-terrain-elevation, earth-science-topography-land-surface-terrain-elevation-topographical-relief-maps
Organization: National Aeronautics and Space Administration
NASA Shuttle Radar Topography Mission Global 3 arc second number V003

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of NASA Making Earth System Data Records for Use in Research Environments ([MEaSUREs](https://earthdata.nasa.gov/about/competitive-programs/measures )) SRTM, which includes the global 3 arc second (~90 meter) number product. The NASA SRTM data sets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA - previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. This collaboration aims to generate a near-global digital elevation model (DEM) of Earth using radar interferometry. SRTM was the primary (and virtually only) payload on the STS-99 mission of the Space Shuttle Endeavour, which launched February 11, 2000 and flew for 11 days. The SRTM swaths extended from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km), creating swaths ~225 km wide, and consisted of all land between 60° N and 56° S latitude to account for 80% of Earth's total landmass. Ancillary one-byte (0 to 255) "NUM" (number) files were produced for NASA SRTM Version 3. These files have names corresponding to the elevation files, except with the extension ".NUM" (such as N37W105.NUM). The elevation files use the extension ".HGT", meaning height (such as N37W105.HGT). The separate NUM file indicates the source of each DEM pixel; the number of ASTER scenes used (up to 100), if ASTER; and the number of SRTM data takes (up to 24), if SRTM. The NUM file for both 3 arc second products (whether sampled or averaged) references the 3 x 3 center pixel. Note that NUMs less than 6 are water and those greater than 10 are land. The 3 arc second data was derived from the 1 arc second using sampling and averaging methods. (See Figure 3 in the User Guide) The global 3 arc second number product is also available in NetCDF4 format as the SRTMGL3_NUMNC dataset and can be used with the corresponding SRTMGL3_NC elevation product. Known Issues * Known issues in the NASA SRTM are described in the following publication: * Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249 Improvements/Changes from Previous Version * Voids in the Version 3.0 products have been filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED).

Tags: earth-science-radar-spectral-engineering-radar-imagery, earth-science-topography-land-surface-terrain-elevation, earth-science-topography-land-surface-terrain-elevation-topographical-relief-maps
Organization: National Aeronautics and Space Administration
Nimbus-7 SMMR Antenna Temperatures, Version 1

The SMMR Antenna Temperatures (Nimbus-7) data set consists of antenna temperatures from passive microwave radiometers aboard NOAA's Nimbus-7 satellite. The instrument is the Scanning Multichannel Microwave Radiometer (SMMR). Each file consists of one days worth of data in swath format, i.e. the portion of the Earth's surface viewed by the scanning radiometer. Antenna temperature data are available from NSIDC from October 1978 to August 1987. SMMR was a ten channel passive microwave instrument using six conventional Dicke-type radiometers. It delivered orthogonally polarized antenna temperature data at five frequencies: 6.6, 10.69, 18.0 21.0 and 37.0 GHz. The two 37.0 GHz radiometers operated continuously for each polarization. The other radiometers alternated polarizations on alternate scans. The size of each daily file is 35 MBytes. The data are distributed on FTP. The scanner operated only on alternate days, due to spacecraft power limitations. There are typically at least 14 days of coverage per month, although major data gaps occur in August: in August, 1982, the 4th, 8th, and 16th are missing for both polar regions; in August, 1984, the 13th through the 23rd are missing for both polar regions.

Tags: earth-science-microwave-spectral-engineering-antenna-temperature
Organization: National Aeronautics and Space Administration
NASA Shuttle Radar Topography Mission Global 1 arc second Number NetCDF V003

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of the NASA Making Earth System Data Records for Use in Research Environments ([MEaSUREs](https://earthdata.nasa.gov/about/competitive-programs/measures )) version SRTM, which includes the global 1 arc second (~30 meter) product. NASA Shuttle Radar Topography Mission (SRTM) datasets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA - previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. The purpose of SRTM was to generate a near-global digital elevation model (DEM) of the Earth using radar interferometry. SRTM was a primary component of the payload on the Space Shuttle Endeavour during its STS-99 mission. Endeavour launched February 11, 2000 and flew for 11 days. SRTM collected data in swaths, which extend from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km). These swaths are ~225 km wide, and consisted of all land between 60° N and 56° S latitude. This accounts for about 80% of Earth's total landmass. Each SRTMGL1 data tile contains a mosaic and blending of elevations generated by averaging all "data takes" that fall within that tile. These elevation files use the extension ".HGT", meaning height (such as N37W105.SRTMGL1.HGT). The primary goal of creating the Version 3 data was to eliminate voids that were present in earlier versions of SRTM data. In areas with limited data, existing topographical data were used to supplement the SRTM data to fill the voids. The source of each elevation pixel is identified in the corresponding [SRTMGL1N](https://doi.org/10.5067/MEaSUREs/SRTM/SRTMGL1N.003) product (such as N37W105.SRTMGL1N.NUM). The global 1 arc second SRTM product is also available in NetCDF4 format as the SRTMGL1_NC dataset with the source of each elevation pixel in the corresponding SRTMGL1_NUMNC product. Known Issues * Known issues in the NASA SRTM are described in the following publication: * Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249 Improvements/Changes from Previous Version * Voids in the Version 3.0 products have been filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED).

Tags: earth-science-radar-spectral-engineering-radar-imagery, earth-science-topography-land-surface-terrain-elevation, earth-science-topography-land-surface-terrain-elevation-topographical-relief-maps
Organization: National Aeronautics and Space Administration
NASA Shuttle Radar Topography Mission United States 1 arc second

The SRTMUS1 collection was retired on November 20, 2014, when global SRTM data became available at a resolution of 1 arc second. The data for the United States are included in the [SRTMGL1](https://doi.org/10.5067/MEaSUREs/SRTM/SRTMGL1.003) dataset. The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of the NASA Making Earth System Data Records for Use in Research Environments ([MEaSUREs](https://earthdata.nasa.gov/about/competitive-programs/measures)) version SRTM, which includes the United States 1 arc second (~30 meter) product. NASA Shuttle Radar Topography Mission (SRTM) datasets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA - previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. The purpose of SRTM was to generate a near-global digital elevation model (DEM) of the Earth using radar interferometry. SRTM was a primary component of the payload on the Space Shuttle Endeavour during its STS-99 mission. Endeavour launched February 11, 2000, and ﬂew for 11 days. Each SRTMUS1 data tile contains a mosaic and blending of elevations generated by averaging all "data takes" that fall within that tile. These elevation files use the extension “.HGT”, meaning height (such as N37W105.SRTMUS1.HGT). The primary goal of creating the Version 3 data was to eliminate voids that were present in earlier versions of SRTM data. In areas with limited data, existing topographical data were used to supplement the SRTM data to fill the voids. The source of each elevation pixel is identified in the corresponding [SRTMUS1N](http://doi.org/10.5067/MEaSUREs/SRTM/SRTMUS1N.003) product (such as N37W105.SRTMUS1N.NUM). SRTM collected data in swaths, which extend from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km). These swaths are ~225 km wide and consisted of all land between 60 degrees N and 56 degrees S latitude. This accounts for about 80% of Earth’s total landmass. Known Issues * Known issues in the NASA SRTM are described in the following publication: Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249 Improvements/Changes from Previous Version * Voids in the Version 3.0 products have been filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED).

Tags: earth-science-radar-spectral-engineering-radar-imagery, earth-science-topography-land-surface-terrain-elevation, earth-science-topography-land-surface-terrain-elevation-digital-elevation-terrain-model-dem, earth-science-topography-land-surface-terrain-elevation-topographical-relief-maps
Organization: National Aeronautics and Space Administration
NASA Shuttle Radar Topography Mission Global 1 arc second V003

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of the NASA Making Earth System Data Records for Use in Research Environments ([MEaSUREs](https://earthdata.nasa.gov/about/competitive-programs/measures )) version SRTM, which includes the global 1 arc second (~30 meter) product. NASA Shuttle Radar Topography Mission (SRTM) datasets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA - previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. The purpose of SRTM was to generate a near-global digital elevation model (DEM) of the Earth using radar interferometry. SRTM was a primary component of the payload on the Space Shuttle Endeavour during its STS-99 mission. Endeavour launched February 11, 2000 and flew for 11 days. SRTM collected data in swaths, which extend from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km). These swaths are ~225 km wide, and consisted of all land between 60° N and 56° S latitude. This accounts for about 80% of Earth's total landmass. Each SRTMGL1 data tile contains a mosaic and blending of elevations generated by averaging all "data takes" that fall within that tile. These elevation files use the extension ".HGT", meaning height (such as N37W105.SRTMGL1.HGT). The primary goal of creating the Version 3 data was to eliminate voids that were present in earlier versions of SRTM data. In areas with limited data, existing topographical data were used to supplement the SRTM data to fill the voids. The source of each elevation pixel is identified in the corresponding [SRTMGL1N](https://doi.org/10.5067/MEaSUREs/SRTM/SRTMGL1N.003) product (such as N37W105.SRTMGL1N.NUM). The global 1 arc second SRTM product is also available in NetCDF4 format as the SRTMGL1_NC dataset with the source of each elevation pixel in the corresponding SRTMGL1_NUMNC product. Known Issues * Known issues in the NASA SRTM are described in the following publication: * Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249 Improvements/Changes from Previous Version * Voids in the Version 3.0 products have been filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED).

Tags: earth-science-radar-spectral-engineering-radar-imagery, earth-science-topography-land-surface-terrain-elevation, earth-science-topography-land-surface-terrain-elevation-digital-elevation-terrain-model-dem, earth-science-topography-land-surface-terrain-elevation-topographical-relief-maps
Organization: National Aeronautics and Space Administration