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MODIS/Aqua Near Real Time (NRT) Aerosol 5-Min L2 Swath 10km

The MODIS level-2 atmospheric aerosol product (MYD04_L2) continues to provide full global coverage of aerosol properties from the Dark Target (DT) and Deep Blue (DB) algorithms. The DT algorithm is applied over ocean and dark land (e.g., vegetation), while the DB algorithm now covers the entire land areas including both dark and bright surfaces. Both results are provided on a 10x10 pixel scale (10 km at nadir). Each MYD04_L2 product file covers a five-minute time interval. The output grid is 135 pixels in width by 203 pixels in length. Every tenth file has an output grid size of 135 by 204 pixels. MYD04_L2 product files are stored in Hierarchical Data Format (HDF-EOS).Based on C5 validation studies, a number of Science Data Sets (SDSs) have been deleted from the DT product (Angstrom_Exponent_Land, Optical_Depth_Small_Land, etc.) while a number of SDSs have been renamed or added. A number of algorithm changes have lead to significant changes in regional aerosol product statistics (see link above). For C6, the DT algorithm team now provides a new 3 km spatial resolution product intended for the air quality community; this is provided in a separate file (M*D04_3K).In C5, the DB algorithm was limited to only bright targets. With C6, the DB team has expanded coverage to include both bright targets and vegetated regions, using NDVI information in addition to a precalculated surface reflectance database. New DB products for C6 include an estimate on the aerosol retrieval uncertainty to assist with error analyses as well as a best estimate SDS containing the aerosol optical thickness data with quality assurance flags already applied (SDS names Deep_Blue_Aerosol_Optical_Depth_550_Land_Estimated_Uncertainty and Deep_Blue_Aerosol_Optical_Depth_550_Land_Best_Estimate respectively). In addition to separate DT and DB retrievals, the C6 product now provides a merged (SDS) that combines both types of retrievals (SDS name AOD_550_Dark_Target_Deep_Blue_Combined). This SDS uses a combination of scene NDVI and retrieval Quality Assessment (QA) assignments to select one of the retrievals (if any) or an average of the two retrievals. Ocean retrievals from the DT algorithm are also provided if they have a sufficiently high retrieval QA value.The file consists of following pixel level gridded aerosol parameters. These pixel level gridded aerosol parameters are stored as Scientific Data Sets(SDS) within the file:MODIS Data Category & ParametersSpatial & Temporal Resolution:Longitude, Latitude, Scan_Start_TimeSolar and Sensor Viewing Geometry:Solar_Zenith, Solar_Azimuth, Sensor_Zenith, Sensor_AzimuthAerosol Parameters for Land & Ocean (Combined):Scattering_Angle, Land_sea_Flag, Aerosol_Cldmask_Land_Ocean, Cloud_Pixel_Distance_Land_Ocean, Land_Ocean_Quality_Flag, Optical_Depth_Land_And_Ocean, Image_Optical_Depth_Land_And_Ocean, Average_Cloud_Pixel_Distance_Land_OceanAerosol Parameters from Land Retrieval Algorithm:Aerosol_Type_Land, Fitting_Error_Land, Surface_Reflectance_Land, Corrected_Optical_Depth_Land, Corrected_Optical_Depth_Land_wav2p1, Optical_Depth_Ratio_Small_Land, Number_Pixels_Used_Land, Mean_Reflectance_Land, STD_Reflectance_Land, Mass_Concentration_Land, Aerosol_Cloud_Fraction_Land, Quality_Assurance_Land, Topographic_Altitude_LandAerosol Parameters from Ocean Retrieval Algorithm:Solution_Index_Ocean_Small, Solution_Index_Ocean_Large, Effective_Optical_Depth_Best_Ocean, Effective_Optical_Depth_Average_Ocean, Optical_Depth_Small_Best_Ocean, Optical_Depth_Small_Average_Ocean, Optical_Depth_Large_Best_Ocean, Optical_Depth_Large_Average_Ocean, Mass_Concentration_Ocean, Aerosol_Cloud_Fraction_Ocean, Effective_Radius_Ocean, Effective_Optical_Depth_0p55um_Ocean, PSML003_Ocean, Asymmetry_Factor_Best_Ocean, Asymmetry_Factor_Average_Ocean, Backscattering_Ratio_Best_Ocean, Backscattering_Ratio_Average_Ocean, Angstrom_Exponent_1_Ocean, Angstrom_Exponent_2_Ocean, Least_Squares_Error_Ocean, Optical_Depth_Ratio_Small_Ocean_0.55micron, Optical_Depth_by_models_ocean, Number_Pixels_Used_Ocean, Mean_Reflectance_Ocean;, STD_Reflectance_Ocean, byte Quality_Assurance_Ocean, Glint_Angle, Wind_Speed_Ncep_OceanAerosol Parameters from Deep Blue Retrieval Algorithm:Deep_Blue_Aerosol_Optical_Depth_550_Land, Deep_Blue_Spectral_Aerosol_Optical_Depth_Land, Deep_Blue_Angstrom_Exponent_Land, Deep_Blue_Spectral_Single_Scattering_Albedo_Land, Deep_Blue_Spectral_Surface_Reflectance_Land, Deep_Blue_Spectral_TOA_Reflectance_Land, Deep_Blue_Number_Pixels_Used_550_Land, Deep_Blue_Aerosol_Optical_Depth_550_Land_STD, Deep_Blue_Cloud_Fraction_Land, Deep_Blue_Aerosol_Optical_Depth_550_Land_QA_Flag, Deep_Blue_Algorithm_Flag_Land, Deep_Blue_Aerosol_Optical_Depth_550_Land_Best_Estimate, Deep_Blue_Aerosol_Optical_Depth_550_Land_Estimated_UncertaintyAerosol Parameters from Dark Target/Deep Blue Combine Algorithm:AOD_550_Dark_Target_Deep_Blue_Combined, AOD_550_Dark_Target_Deep_Blue_Combined_QA_Flag, AOD_550_Dark_Target_Deep_Blue_Combined_Algorithm_FlagThese aerosol par

restrictednotspecifiedAug 2025View details →

Ground-Based GNSS-based Upper Atmospheric Realtime Disaster Information and Alert Network (GUARDIAN) GLONASS daily accumulated real-time Precise Orbit Determination (POD) Clock Corrections (60-second sampling, 24-hour files) from NASA CDDIS

This product contains a high-rate time series of clock biases for healthy satellites in the GLONASS constellation that are accumulated every minute throughout the day. In addition, formal 1-sigma uncertainties for the corrections are provided. The product is generated at JPL's Global Differential GPS Operations Centers in real-time. The data in this product can be concatenated with other daily products to provide larger coverage in time.

MODIS/Aqua Near Real Time (NRT) Coarse Sea Ice Extent 5-Min L2 Swath 5km

MODIS/Aqua Near Real Time (NRT) Coarse Sea Ice Extent 5-Min L2 Swath 5km (MYD29L2C) data set contains fields for sea ice by reflectance, sea ice by reflectance pixel Quality Assessment (QA), Ice Surface Temperature (IST), IST pixel QA, latitudes, and longitudes in Hierarchical Data Format-Earth Observing System (HDF-EOS) format, along with corresponding metadata. Latitude and longitude geolocation fields are at 5 km resolution, while all other fields are at 1 km resolution. The sea ice algorithm uses a Normalized Difference Snow Index (NDSI) modified for sea ice to distinguish sea ice from open ocean based on reflective and thermal characteristics. Data are stored in HDF-EOS format, and are available from 24 February 2000 to present via FTP. Data can also be obtained in GeoTIFF format by ordering the data through the Data Pool.

Ground-Based Global Navigation Satellite System (GNSS) Data (1-second sampling, real-time streams) from NASA CDDIS

Global Navigation Satellite System (GNSS) real-time 1 to multi-second sampled data available from the Crustal Dynamics Data Information System (CDDIS). Global Navigation Satellite System (GNSS) provide autonomous geo-spatial positioning with global coverage. GNSS real-time data sets from ground receivers at the CDDIS consist primarily of the data from the U.S. Global Positioning System (GPS) and the Russian GLObal NAvigation Satellite System (GLONASS). Other GNSS (Europe’s Galileo, China’s Beidou, Japan’s Quasi-Zenith Satellite System/QZSS, the Indian Regional Navigation Satellite System/IRNSS, and worldwide Satellite Based Augmentation Systems/SBASs) are similar to the U.S. GPS in terms of the satellite constellation, orbits, and signal structure; CDDIS began streaming real-time data from these systems in 2015. The real-time observation data from a global permanent network of ground-based receivers are transmitted from the CDDIS in 1 to multi-second intervals in raw receiver or RTCM (Radio Technical Commission for Maritime Services) format.

Sentinel-5P TROPOMI Near-Real-Time (NRT) Tropospheric NO2 1-Orbit L2 5.5km x 3.5km V2 (S5P_L2NO2__HiR_NRT) at GES DISC

The Sentinel-5P TROPOMI Near Real Time (NRT) Tropospheric NO2 1-Orbit L2 5.5km x 3.5km V2 (S5P_L2__NO2____HiR_NRT) at GES DISC is the near real time version of the offline S5P_L2__NO2____HiR data product. These data are typically available within three hours of measurement as required by the Land Atmosphere NRT Capability Earth Observing System (LANCE). These data are intended for a rapid turnaround assessment and are only archived for up to ten days. Users who require a longer data record, or wish to conduct rigorous analysis should use the offline version of this product S5P_L2__NO2____HiR. The Copernicus Sentinel-5 Precursor (Sentinel-5P or S5P) satellite mission is one of the European Space Agency's (ESA) new mission family - Sentinels, and it is a joint initiative between the Kingdom of the Netherlands and the ESA. The sole payload on Sentinel-5P is the TROPOspheric Monitoring Instrument (TROPOMI), which is a nadir-viewing 108 degree Field-of-View push-broom grating hyperspectral spectrometer, covering the wavelength of ultraviolet-visible (UV-VIS, 270nm to 495nm), near infrared (NIR, 675nm to 775nm), and shortwave infrared (SWIR, 2305nm-2385nm). Sentinel-5P is the first of the Atmospheric Composition Sentinels and is expected to provide measurements of ozone, NO2, SO2, CH4, CO, formaldehyde, aerosols and cloud at high spatial, temporal and spectral resolutions. The TROPOMI retrieval of total and tropospheric NO2, is based on the DOMINO approach, a DOAS retrieval, a pre-calculated air-mass factor (AMF) look-up table, and a data assimilation/chemistry transport model for the separation of the stratospheric and tropospheric contributions to the NO2 column. It also include many retrieval developments of the European Quality Assurance for Essential Climate Variables (QA4ECV) project. Data are stored in individual files, or granules, that contain one orbit of information. The data are stored in netCDF4 data format and files and complete files are ~60 MB.

restrictednotspecifiedApr 2025View details →

GHRSST Level 3U Global Global Near-Real Subskin Sea Surface Temperature version 8.2 (v8.2) from the Advanced Microwave Scanning Radiometer 2 (AMSR2) on the GCOM-W satellite by REMSS

This product contains a near-real-time (NRT) Level-3U Sea Surface Temperature (SST) (identified by "_rt_" within the file name) for the Group for High Resolution Sea Surface Temperature (GHRSST) Project, which is derived from the Advanced Microwave Scanning Radiometer 2 (AMSR2) by Remote Sensing Systems (RSS, or REMSS). AMSR2 was launched on 18 May 2012, onboard the Global Change Observation Mission - Water (GCOM-W) satellite developed by the Japan Aerospace Exploration Agency (JAXA). The GCOM-W mission aims to establish the global and long-term observation system to collect data, which is needed to understand mechanisms of climate and water cycle variations, and demonstrate its utilization. AMSR2 onboard the first generation of the GCOM-W satellite will continue Aqua/AMSR-E observations of water vapor, cloud liquid water, precipitation, SST, sea surface wind speed, sea ice concentration, snow depth, and soil moisture. AMSR2 is a remote sensing instrument for measuring weak microwave emission from the surface and the atmosphere of the Earth. The antenna of AMSR2 rotates once per 1.5 seconds and obtains data over a 1450 km swath. This conical scan mechanism enables AMSR2 to acquire a set of daytime and nighttime data with more than 99% coverage of the Earth every 2 days. The NRT SST is made as available as soon as possible, generally within 3 hours latency. The v8.2 supersedes the previous v8a dataset which can be found at https://www.doi.org/10.5067/GHAM2-3TR8A.

MODIS/Aqua Near Real Time (NRT) Total Precipitable Water Vapor 5-Min L2 Swath 1km and 5km

The MODIS level-2 atmospheric precipitable water product consists of total atmospheric column water vapor amounts (and ancillary parameters) over clear land areas of the globe, over extended clear oceanic areas with the Sun glint, and above clouds over both land and ocean. The shortname for this level-2 MODIS total precipitable water vapor product is MYD05_L2. In Collection 6, MODIS column water vapor (MYD05) datasets continue to be separately available from infrared and near-infrared methods.The estimates based on a near-infrared algorithm uses only daytime measurements with solar zenith angle less than 72 degrees. The retrieval algorithm relies on observations of water vapor attenuation of near-infrared solar radiation reflected by surfaces and clouds. The product is produced only over areas that have reflective surfaces in the near-infrared. The near-infrared algorithm refinement for this product is no longer being supported by NASA and as such there has been no update to this algorithm for C6.The clear-sky infrared-derived precipitable water vapor generated for both daytime and nighttime conditions is derived from the previously reprocessed Atmospheric Profile (MOD07) C6 product that included a new layer scheme for total precipitable water.MYD05_L2 product files are stored in Hierarchical Data Format (HDF-EOS). The file contains 13 gridded parameters. Each of these gridded MYD05 parameters is stored as a Scientific Data Set (SDS) within the HDF-EOS file. The Water Vapor and Quality Assurance SDS's are stored at 1 kilometer (near-infrared) and 5 kilometer (for infrared) pixel resolution. All other SDS's (those relating to time, geolocation, and viewing geometry) are stored at 5 kilometer pixel resolution. The Cloud Mask SDS, copied from the MOD35_L2 Product is stored at 1 kilometer resolution. Each file is roughly 3.5 MB in size, and the total data volume is approximately 1 GB/day.MODIS Data Category and ParametersSpatial and Temporal Resolution:latitude,longitudescan start timeSolar and Sensor Viewing Geometry:solar zenith angle, solar azimuth angle, sensor zenith angle, sensor azimuth angleWater Vapor Parameters:near-infrared estimated water vapor(1km), water vapor correction factors(1km), infrared estimated water vapor(5km)Quality Assurance & Statistical Parameters:QA flags for near-infrared retrieval(1km), QA flags for infrared retrieval(5km), cloud mask(1km)The near-infrared water vapor estimates are very sensitive to boundary layer water vapor since they are derived from atmospheric attenuation of surface reflected radiances. This product is essential to the understanding of hydrological cycle, aerosol properties, aerosol-cloud interactions, energy budget, and climate.For more information about the MYD05_L2 product, visit the MODIS-Atmosphere site at:http://modis-atmos.gsfc.nasa.gov/MOD05_L2/orVisit the MODIS Science Team homepage:http://modis.gsfc.nasa.gov/data/dataprod/

MODIS/Terra Near Real Time (NRT) Aerosol 5-Min L2 Swath 3km

The MODIS level-2 atmospheric aerosol product provides retrieved ambient aerosol optical properties (e.g., optical thickness and size distribution), mass concentration, look-up table derived reflected and transmitted fluxes, as well as quality assurance and other ancillary parameters, globally over ocean and near globally over land.In Collection 5, and earlier collections, there was only one aerosol product (MOD04_L2) at 10km at nadir spatial resolution. For C6, the Dark Target (DT) Aerosol algorithm team now provides a new 3 km spatial resolution product intended for the air quality community. The short name for this product is MOD04_3k. The MOD04_3K product is based on the same algorithm and using the same Look Up Tables as the standard Dark Target aerosol product. Because of finer resolution, subtle differences are made in selecting pixels for retrieval and in determining QA. The only differences between the existing 10km algorithm and the new 3km algorithm are: 1) the size of the pixel-arrays defining each retrieval box (used 6x6 retrieval boxes of 36 pixels at 0.5km resolution for 3km algorithm as oppose to 20x20 retrieval boxes of 400 pixels at 0.5km resolution used for 10km product); 2) the minimum percentage of ???good??? pixels required for a retrieval (required a minimum of 5 pixels over ocean and 6 pixels over land instead of a minimum of 10 pixels over ocean or 12 pixels over land for (more for high quality) 10km product retrieval); 3) the 10km algorithm attempts a ???poor quality??? retrieval while 3km algorithm does not. Everything else is the same in two products.Recommendations:Global studies should continue to make use of the more robust and well-studied 10 km product. The 3 km product???s use should be restricted to obvious situations that require finer resolution.Only the AOD at 550 nm has been studied in depth at this point. Difference in AOD at wavelengths, and differences in the size parameters over ocean are possible. More validation will be forthcoming.Aerosol-cloud studies with the 3 km product should proceed cautiously. At this time, we do not specifically know how the 3 km product is affected in the proximity of clouds.While the air quality community will be eager to apply the 3 km product across an urban landscape, this must proceed cautiously because of known artifacts in the product over urban surfaces.The power of the 3 km product is on local, not global, scales.List of SDSs available at 3 km Spatial & Temporal Resolution:Longitude, Latitude, Scan_Start_TimeSolar and Sensor Viewing Geometry:Solar_Zenith, Solar_Azimuth, Sensor_Zenith, Sensor_AzimuthAerosol Parameters for Land & Ocean (Combined):Scattering_Angle, Land_sea_Flag,Optical_Depth_Land_And_Ocean, Image_Optical_Depth_Land_And_Ocean, Land_Ocean_Quality_FlagAerosol Parameters from Land Retrieval Algorithm: Aerosol_Type_Land, Fitting_Error_Land, Surface_Reflectance_Land, Corrected_Optical_Depth_Land, Corrected_Optical_Depth_Land_wav2p1, Optical_Depth_Ratio_Small_Land, Number_Pixels_Used_Land, Mean_Reflectance_Land, STD_Reflectance_Land, floatMass_Concentration_Land, Aerosol_Cloud_Fraction_Land, byteQuality_Assurance_Land, Topographic_Altitude_LandAerosol Parameters from Ocean Retrieval Algorithm:Glint_Angle, Wind_Speed_Ncep_Ocean, Solution_Index_Ocean_Small, Solution_Index_Ocean_Large, Effective_Optical_Depth_Best_Ocean, Effective_Optical_Depth_Average_Ocean, Optical_Depth_Small_Best_Ocean, Optical_Depth_Small_Average_Ocean, Optical_Depth_Large_Best_Ocean, Optical_Depth_Large_Average_Ocean, floatMass_Concentration_Ocean, Aerosol_Cloud_Fraction_Ocean, Effective_Radius_Ocean, Cloud_Condensation_Nuclei_Ocean, Asymmetry_Factor_Best_Ocean, Asymmetry_Factor_Average_Ocean, Backscattering_Ratio_Best_Ocean, Backscattering_Ratio_Average_Ocean, Angstrom_Exponent_1_Ocean, Angstrom_Exponent_2_Ocean, Least_Squares_Error_Ocean, Optical_Depth_Ratio_Small_Ocean_0.55micron, Optical_Depth_by_models_ocean, Number_Pixels_Used_Ocean, Mean_Reflectance_Ocean, STD_Reflectance_Ocean, byteQuality_Assurance_Ocean See the MODIS Science Team homepage for more data set information: http://modis-atmos.gsfc.nasa.gov/Webinar2014/MODIS_Atmos_Webinar-2_Munchak_3kmaerosol.pdf or visit the MODIS Atmosphere Team homepage for 10km product information:http://modis-atmos.gsfc.nasa.gov/MOD04_L2/

MODIS/Terra Near Real Time (NRT) Vegetation Indices Daily Rolling-8-Day L3 Global 250m SIN Grid

The MODIS Near Real Time (NRT) level-3 Vegetation Indices Daily Rolling8Day data, MOD13Q4N, are provided everyday at 250-meter spatial resolution as a gridded leve-3 product in the Sinusoidal projection. Vegetation indices are used for global monitoring of vegetation conditions and are used in products displaying land cover and land cover changes. These data may be used as input for modeling global biogeochemical and hydrologic processes and global and regional climate. These data also may be used for characterizing land surface biophysical properties and processes including primary production and land cover conversion.Note: This is a near real-time product only. Standard historical data and imagery for MOD13Q4N (250m) and MOD13A4N (500m) are not available. Users can either use the NDVI standard products from LAADS web (https://ladsweb.modaps.eosdis.nasa.gov/search/) or access the science quality MxD09[A1/Q1] data and create the NDVI product of their own.

restrictednotspecifiedAug 2025View details →

Ground-Based GNSS-based Upper Atmospheric Realtime Disaster Information and Alert Network (GUARDIAN) GLONASS daily accumulated real-time Precise Orbit Determination (POD) orbits (60-second sampling, 24-hour files) from NASA CDDIS

This product contains a time series of position and velocity components for healthy satellites in the GLONASS constellation that are accumulated every minute throughout the day. In addition, formal 1-sigma uncertainties for the positions and velocities are provided. The product is generated at JPL's Global Differential GPS Operations Centers in real-time. The data in this product can be concatenated with other daily products to provide larger coverage in time.

MLS/Aura Near-Real-Time L2 Water Vapor (H2O) Mixing Ratio V005 (ML2H2O_NRT) at GES DISC

ML2H2O_NRT is the EOS Aura Microwave Limb Sounder (MLS) Near-Real-Time (NRT) product for water vapor (H2O). This product contains H2O profiles derived from the 190 GHz region. The NRT data are typically available within 3 hours of observation and are broken into files containing about 15 minutes of data. The most recent 7 days of data are available online. Spatial coverage is near-global (-82 degrees to +82 degrees latitude), with each profile spaced 1.5 degrees or ~165 km along the orbit track (roughly 15 orbits per day). The vertical coverage is from 147 to 1 hPa. The MLS NRT algorithm uses a simplified fast forward model to meet Near Real Time data latency requirements and are therefore not as accurate as the retrievals that constitute the standard MLS products. Nevertheless the results are scientifically useful in selected regions of the Earth's atmosphere provided that the data are screened according to the recommendations in the MLS NRT User Guide and the MLS L2 Data Quality Document for Standard Products.

MODIS/Aqua Near Real Time (NRT) Surface Reflectance Daily L2G Global 250m SIN Grid

The MODIS Near Real Time (NRT) Surface Reflectance products are an estimate of the surface spectral reflectance as it would be measured at ground level in the absence of atmospheric scattering or absorption. Low-level data are corrected for atmospheric gases and aerosols, yielding a level-2 basis for several higher-order gridded level-2 (L2G) and level-3 products.MYD09GQ provides Bands 1 and 2 at a 250-meter resolution in a daily gridded L2G product in the Sinusoidal projection. Science Data Sets provided for this product include reflectance for Bands 1 and 2 a quality rating observation coverage and observation number. This product is meant to be used in conjunction with MYD09GA where important quality and viewing geometry information is stored.Additional information at LPDAAC:https://lpdaac.usgs.gov/dataset_discovery/modis/modis_products_table

MODIS/Terra Near Real Time L3 Value-added Aerosol Optical Depth

MODIS was launched aboard the Terra satellite on December 18, 1999 (10:30 am equator crossing time) as part of NASA's Earth Observing System (EOS) mission. MODIS with its 2330 km viewing swath width provides almost daily global coverage. It acquires data in 36 high spectral resolution bands between 0.415 to 14.235 micron with spatial resolutions of 250m(2 bands), 500m(5 bands),and 1000m (29 bands). MODIS sensor counts, calibrated radiances, geolocation products and all derived geophysical atmospheric and ocean products are archived at various DAACs and has been made available to public since April 2000.The shortname for this level-3 MODIS aerosol product is MODAODHD. The Naval Research Laboratory and the University of North Dakota developed this value-added aerosol optical depth dataset based on MODIS Level 2 aerosol products. MODAODHD is a gridded product and is specifically designed for quantitative applications including data assimilation and model validation. It is available through LANCE-MODIS. It offers several enhancements over the MODIS Level 2 data on which it is based. These enhancements include stringent filtering to reduce outliers, eliminate cloud contamination, and exclude conditions where aerosol detection is likely to be inaccurate; reduction of systematic biases over land and ocean by empirical corrections; reduction of random variation in AOD values by spatial averaging; quantitative estimation of uncertainty for each AOD data point.The MxDAODHD granules are produced every six hours, and time-stamped 00:00, 06:00, 12:00, and 18:00 (all times UTC). Each granule includes MODIS observations from +/-3 hours from the timestamp (e.g. 12:00 product includes MODIS data from 09:00-15:00 UTC). Production is initiated as soon as the Level 2 inputs become available in the LANCE system.See the LANCE-MODIS page for more dataset information: https://earthdata.nasa.gov/earth-observation-data/near-real-time/download-nrt-data/modis-nrt

MODIS/Terra Near Real Time (NRT) Calibrated Radiances 5-Min L1B Swath 250m

The 250 meter MODIS Level 1B Near Real Time (NRT) data set contains calibrated and geolocated at-aperture radiances for 2 discrete bands located in the 0.62 to 0.88 micron region of the electromagnetic spectrum. These data are generated from the MODIS Level 1A scans of raw radiance and in the process converted to geophysical units of W / (m^2 um sr). In addition, the Earth Bi-directional Reflectance Distribution Function (BRDF) may be determined for these solar reflective bands through knowledge of the solar irradiance (e.g., determined from MODIS solar diffuser data, and from the target illumination geometry). Additional data are provided including quality flags, error estimates and calibration data. Channel locations for the MODIS 250 meter data are as follows: Band Center Wavelength (um) Primary Use ---- ---------------------- ----------- 1 0.620 - 0.670 Land/Cloud Boundaries 2 0.841 - 0.876 Land/Cloud Boundaries Separate L1B products are available for the five 500 m resolution channels (MOD02HKM) and the twenty-nine 1 km resolution channels (MOD021KM). For the 500 m product, there are actually seven channels available since the data from the two 250 m channels have been aggregated to 500 m resolution. Similarly, for the 1 km product, all 36 MODIS channels are available since the data from the two 250 m and five 500 m channels have been aggregated into equivalent 1 km pixel values. Spatial resolution for pixels at nadir is 250 m, degrading to 1.2 km in the along-scan direction and 0.5 km in the along-track direction for pixels located at the scan extremes. A 55 degree scanning pattern at the EOS orbit of 705 km results in a 2330 km orbital swath width and provides global coverage every one to two days. A single MODIS Level 1B 250 m granule will contain a scene built from 203 scans sampled 5416 times in the cross-track direction, corresponding to approximately 5 minutes worth of data; thus 288 granules will be produced per day. Since an individual MODIS scan will contain 40 along-track spatial elements for the 250 m channels, the scene will be composed of (5416 x 8120) pixels, resulting in a spatial coverage of (2330 km x 2040 km). Due to the MODIS scan geometry, there will be increasing scan overlap beyond about 17 degrees scan angle. To summarize, the MODIS L1B 250 m data product consists of: 1. Calibrated radiances and uncertainties for (2) 250 m reflected solar bands 2. Subsampled geolocation at every 4th 250 m pixel across and along track, i.e., a geolocation point every kilometer 3. Satellite and solar angles subsampled at the above frequency 4. Calibration data for all channels (scale and offset) 5. Comprehensive set of file-level metadata summarizing the spatial, temporal and parameter attributes of the data, as well as auxiliary information pertaining to instrument status and data quality characterization The MODIS L1B 250 m data are stored in the Earth Observing System Hierarchical Data Format (HDF-EOS) which is an extension of HDF as developed by the National Center for Supercomputer Applications (NCSA) at the University of Illinois. A typical file size will be approximately 170 MB. Environmental information derived from MODIS L1B measurements will offer a comprehensive and unprecedented look at terrestrial, atmospheric, and ocean phenomenology for a wide and diverse community of users throughout the world. The Shortname for this product is MOD02QKM

GPM Ground Validation Naval Research Laboratory (NRL) Near-Real Time Rain Rates IFloodS V1

The GPM Ground Validation Naval Research Laboratory (NRL) Near-Real Time Rain Rates IFloodS data product was created for the GPM Iowa Flood Studies (IFloodS) field campaign from April 23, 2013 through June 30, 2013. The IFloodS field campaign was a ground measurement campaign that took place in eastern Iowa. The goals of the campaign were to collect detailed measurements of precipitation at the Earth’s surface using ground instruments and advanced weather radars and to simultaneously collect data from satellites passing overhead. This NRL real time rain rates data product was produced using the Probability Matching Method with rain gauge, Defense Meteorological Satellite Program (DMSP) F15 Special Sensor Microwave - Imager (SSM/I), and DMSP F16 Special Sensor Microwave - Imager/Sounder (SSMIS) data. This data product includes rain rate estimates and files are available in netCDF-4 and binary formats, as well as corresponding browse imagery in JPG format.

Real-Time Structural Overload Control via Control Allocation Optimization Project

This control methodology utilizes real-time vehicle structural load and&nbsp;shape measurements to actively respond to and protect against vehicle&nbsp;damage due to structural overload. The innovation utilizes critical point&nbsp;load feedback within an optimal control allocation architecture that&nbsp;constrains the load at those critical points while still producing the&nbsp;control response commanded by a pilot. Specifically, the technology&nbsp;monitors the loads at critical control points and shifts the loading away&nbsp;from points at or near their limits.Work to date: Using NASA&rsquo;s Full-Scale Advanced Systems Testbed&nbsp;(FAST) aircraft, the Armstrong team targeted the aileron hinge connection&nbsp;as a critical control point. The experiment produced successful results in simulation and flight, preventing structural overload and yielding good handling&nbsp;characteristics for optimization metrics and load constraint types.Looking ahead:&nbsp;This effort led to being awarded an ARMD seedling fund phase one to further develop the technique and expand the work to other autonomy efforts.&nbsp;Future tests will&nbsp;employ more advanced and unique sensor technologies, such as fiber&nbsp;optic strain sensors. This technology could open the door to truly novel&nbsp;approaches to vehicle and control system design.Benefits<ul><li>Effective: Identifies the optimum control&nbsp;surface usage for a given maneuver for both&nbsp;performance and structural loading</li><li>Automated: Monitors and alleviates stress&nbsp;on critical load points in real time</li><li>Economical: Decreases the need for&nbsp;repairs and general maintenance</li></ul>Applications<ul><li>Jet aircraft</li><li>Rocket controls</li><li>Industrial robotics</li><li>Structural health monitoring and load alleviation</li></ul>

MODIS/Terra Near Real Time (NRT) Level 1B Subsampled Calibrated Radiance 5Km

This Near Real Time (NRT) data type (MOD02SSH) is a subsample from the MODIS Level 1B 1-km data. Every fifth pixel is taken from the MOD021KM product and written out to MOD02SSH. The subsampling starts at the third frame, and at the third line. Here, "frame" and "line" are naming conventions for pixels along and across the scan, respectively. Since MOD02SSH is a subsampled Level 1B , many things from the Level 1B documentation apply as well. That is, the MOD02SSH data productcontains calibrated and geolocated at-aperture radiances for 36 bands generated from MODIS Level 1A scans of raw radiance (MOD 01). The radiance units are in W/(m ^2 um sr). Additional data are provided including quality flags, error estimates and calibration data. Visible, shortwave infrared (SWIR), and Near Infrared (NIR) measurements are made during daytime only, while radiances for Thermal Infrared (TIR) are measured continuously.As it's parent, the MOD02SSH is in HDF-EOS format, and all metadata structures and names are preserved for better convenience. However, some relevant changes are made where appropriate. E.g. the dimension mappings are updated to reflect the new one-to-one correspondance between the data and geolocations. The latter is one of the most important differences: in the MOD02SSH, there is no offset between data and geolocation pixels. The spatial coverage is almost similar to that from MOD021KM (nominally it is 2330 by 2030 km, cross-track by along-track, respectively). The MOD02SSH is produced continuously, and thus the processing provides 2-day repeat observations of the Earth with a repeat orbitpattern every 16 days.The shortname for this product is MOD02SSH

MLS/Aura Near-Real-Time L2 Nitrous Oxide (N2O) Mixing Ratio V005 (ML2N2O_NRT) at GES DISC

ML2N2O_NRT is the EOS Aura Microwave Limb Sounder (MLS) Near-Real-Time (NRT) product for nitrous oxide (N2O). This product contains N2O profiles derived from the 190 GHz region. The NRT data are typically available within 3 hours of observation and are broken into files containing about 15 minutes of data. The most recent 7 days of data are available online. Spatial coverage is near-global (-82 degrees to +82 degrees latitude), with each profile spaced 1.5 degrees or ~165 km along the orbit track (roughly 15 orbits per day). The vertical coverage is from 100 to 1 hPa. The MLS NRT algorithm uses a simplified fast forward model to meet Near Real Time data latency requirements and are therefore not as accurate as the retrievals that constitute the standard MLS products. Nevertheless the results are scientifically useful in selected regions of the Earth's atmosphere provided that the data are screened according to the recommendations in the MLS NRT User Guide and the MLS L2 Data Quality Document for Standard Products.