GeoNEX ONLINE DATAPOOL ----------------------------- Datapool readme file, last updated 2020-07-24. DATA STATUS & RELEASE CADENCE ----------------------------- All product are considered provisional and subject to change. Products are intended to facilitate data exploration and process studies that do not require rigorous validation. These data may be partially validated and improvements are continuing; quality may not be optimal since validation and quality assurance are ongoing. See disclaimer below. GeoNEX gridded products are currently be updated on a semiannual or best effort basis. The release cadence is expected to increase with future product and process improvements. All data is available in the internal datapools (/nex/datapool/) for NEX/NAS users. The data exported on the dataportal is often significantly behind the internal sources, the export or refresh rate will improve with time. Input data from providers are provided only as an convenience for exploration, users should consider the official sources first. DATA DIRECTORIES ----------------------------- * GOES16/GEONEX-L1G/ Top-of-Atmosphere (TOA) reflectance GOES-16 ABI. This product includes the Bidirectional Reflectance Factor (BRF) for Bands 1-6 and Brightness Temperature for Bands 7-16 at the top of the atmosphere measured by the satellite sensor. BRF is defined as the ratio of the radiance reflected from the target surface (e.g., top of atmosphere) in a particular direction to the expected radiance reflected from a perfectly white Lambertian surface in the same direction under the same conditions of illumination and reflection. The phrase "bidirectional" emphasizes that the variable is a function of both solar incident and satellite-viewing angles. Brightness temperature is the temperature of a blackbody that would emit the same amount of radiation as the targeted body in a specified spectral band. It is different from the true surface temperature because (1) the surface is not a perfect blackbody; and (2) it is influenced by atmospheric conditions. For more information on the steps used to create this product see https://www.nasa.gov/geonex. * GOES16/GEONEX-L2/ GOES16 surface reflectance (Surface BRF) estimated through the process of atmospheric correction for Bands 1-6.SR is calculated by removing the atmospheric influence (absorption and scattering by molecules and aerosols) from the TOA reflectance. The data are also filtered for unfavorable conditions (e.g., clouds and shadows) under which the retrieval of SR is not feasible or reliable. Intermediate products include cloud masks, atmospheric aerosol optical thickness (AOT), surface BRDF parameters, and so on. The current surface reflectance dataset is produced with an early version of MAIAC. The accuracy of cloud detection and aerosol retrievals is not yet sufficient for science publications. We are still working on issues with the BRDF model fit and atmospheric correction. The next improved version of MAIAC is in a stage of completion, and the updated results of processing will be available the in near future. * GOES16/NOAA-L1B/ GeoNEX GOES16 INPUTS, provided only as an convenience for exploration. * GOES17/GEONEX-L1G/ Top-of-Atmosphere (TOA) reflectance GOES-17 ABI. Refer to GOES16/GEONEX-L1G/ directory write-up, or the website, for more information. * GOES17/GEONEX-L2/ GOES17 surface reflectance (Surface BRF) estimates. Refer to GOES16/GEONEX-L2/ directory write-up, or the website, for more information. * GOES17/NOAA-L1B/ GeoNEX GOES17 INPUTS, provided only as an convenience for exploration. * HIMAWARI8/GEONEX-L1G/ Top-of-Atmosphere (TOA) reflectance HIMAWARI8. Refer to GOES16/GEONEX-L1G/ directory write-up, or the website, for more information. * HIMAWARI8/GEONEX-L2/ HIMAWARI8 surface reflectance (Surface BRF) estimates. Refer to GOES16/GEONEX-L2/ directory write-up, or the website, for more information. * HIMAWARI8/JMA-L1/ GeoNEX HIMAWARI8 INPUTS, provided only as an convenience for exploration.. See https://www.data.jma.go.jp/mscweb/en/himawari89/space_segment/spsg_sample.html (link valid 2019) for more information. * GK2A/AMI/ GeoNEX GEO-KOMPSAT-2A INPUTS, provided only as an convenience for exploration. See https://nmsc.kma.go.kr/enhome/html/base/cmm/selectPage.do?page=satellite.gk2a.intro (link valid 2020) The data set is available to internal hecc users (limited exports). * MOTA/MCD12Q1.006/ This is a convenience data set which is a GeoNEX tiled MCD12Q1 product. MCD12Q1 is a Terra and Aqua combined Moderate Resolution Imaging Spectroradiometer (MODIS) Land Cover Type (MCD12Q1) data product which provides global land cover types. * META/ This directory contains some convenience files and information on spatial information, rudimentary indexing, etc... * NEX-GDM/ This directory contains the auxiliary data set NEX-Gridded Daily Meteorology (NEX-GDM) land surface climate data. The data set is available from 1979 to forward, over the conterminous US and is updated on a best effort basis. NEX-GDM is a 1-km daily climate data, including precipitation, minimum temperature, maximum temperature, dew point temperature, wind speed, and solar radiation. * ML/ This directory contains optical flow model weights. FILE NAMING CONVENTIONS FOR L1G DATA ----------------------------- For all GeoNEX products, the following naming convention is used: ___GLBG_hv_.hdf : HM08_AHI for Himawari 8 AHI, and GO16_ABI or GO17_ABI for GOES ABI, GK2A_AMI for GEO-KOMPSAT-2A AMI. : A two-digit number assigned to each GeoNEX product. Currently, only the Product ID of "05" is available, indicating "Top-of-Atmosphere Reflectance" : Year-Month-Day, e.g., 20180501 : Hour-Minute (UTC time), e.g., 2030 , : Horizontal or Vertical Tile ID : Product version code; currently "02" Note, the input and convenience products may differ from the above naming convention. REFERENCES ----------------------------- Wang, W.; Li, S.; Hashimoto, H.; Takenaka, H.; Higuchi, A.; Kalluri, S.; Nemani, R. An Introduction to the Geostationary-NASA Earth Exchange (GeoNEX) Products: 1. Top-of-Atmosphere Reflectance and Brightness Temperature. Remote Sens. 2020, 12, 1267. https://doi.org/10.3390/rs12081267 COMMUNITY AND SUPPORT ----------------------------- For specific support questions and issues with the data products email support@nas.nasa.gov and include "GeoNEX" in the subject line. DISCLAIMER ----------------------------- The data are considered provisional and subject to change. The data are provided as is without any warranty of any kind, either express or implied, arising by law or otherwise, including but not limited to warranties of completeness, non-infringement, accuracy, merchantability, or fitness for a particular purpose. The user assumes all risk associated with the use of, or inability to use, the data.