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  • CYGNSS L3 Ocean Microplastic Concentration V1.0

    https://cmr.earthdata.nasa.gov/search/concepts/C2142677420-POCLOUD.xml
    Description:

    This dataset contains the version 1.0 CYGNSS level 3 ocean microplastic concentration data record, which provides 18 netCDF files, each containing one month of daily gridded maps of microplastic number density (#/km^2). Microplastic concentration number density is indirectly estimated by an empirical relationship between ocean surface roughness and wind speed (Evans and Ruf, 2021). User caution is advised in regions containing independent, non-correlative factors affecting ocean surface roughness, such as anomalous atmospheric conditions within the Intertropical Convergence Zone, biogenic surfactants (such as algal blooms), oil spills, etc. This product reports microplastic concentration on a daily temporal and 0.25-degree latitude/longitude spatial grid with 30-day, 1 degree latitude/longitude feature resolution, as constrained by the binning and spatiotemporal averaging of the Mean Square Slope (MSS) anomaly (i.e., difference between measured and predicted ocean surface roughness for a given wind speed).

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -37.125 -180 37.125 180

    POCLOUD Short Name: CYGNSS_L3_MICROPLASTIC_V1.0 Version ID: 1.0 Unique ID: C2142677420-POCLOUD

  • CYGNSS Level 1 Calibrated Raw IF Version 1.0

    https://cmr.earthdata.nasa.gov/search/concepts/C2927929087-POCLOUD.xml
    Description:

    The CYGNSS Level 1 Calibrated Raw IF Version 1.0 dataset is produced by the CYGNSS Science Team of the University of Michigan, and it contains the first release, Version 1.0, of the CYGNSS Calibrated Raw Intermediate Frequency (IF) based L1 Product. CYGNSS was launched on 15 December 2016, it is a NASA Earth System Science Pathfinder Mission that was launched with the purpose of collecting the first frequent space‐based measurements of surface wind speeds in the inner core of tropical cyclones. Originally made up of a constellation of eight micro-satellites, the observatories provide nearly gap-free Earth coverage using an orbital inclination of approximately 35° from the equator, with a mean (i.e., average) revisit time of seven hours and a median revisit time of three hours. This product includes several established signal coherence detectors, including the power-ratio P<sub>ratio</sub>, complex zero-Doppler delay waveform and full entropy E<sub>full</sub>, and a novel fast entropy detector E<sub>fast</sub>. Both entropy detectors are provided with two temporal resolutions: 2 ms and 50 ms. Several scattered signal strength products are included: Signal-to-Noise Ratio SNR, reflected power P<sub>g</sub>, reflectivity Γ, and Normalized Bistatic Radar Cross-Section NBRCS. Each of these products is derived using a coherent integration time of T<sub>c </sub>= 1 ms and incoherent integration times of N<sub>inc</sub> = 1000, 500, 250, 100, 50, and 2 ms. Signal strength time series at the shorter (2 and 50 ms) times provides excellent detection of land-water transitions in heterogeneous scenes. Delay Doppler Maps (DDMs) are also generated with high delay (∆τ = 1/16 chip) and Doppler (∆f= 50 Hz) resolution. This suite of coherence detection methods can be used to detect the presence of small inland water bodies.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -38.15 -180 38.15 180

    POCLOUD Short Name: CYGNSS_L1_CAL_RAW_IF_V1.0 Version ID: 1.0 Unique ID: C2927929087-POCLOUD

  • CYGNSS Level 1 Climate Data Record Version 1.0

    https://cmr.earthdata.nasa.gov/search/concepts/C1996881862-POCLOUD.xml
    Description:

    This Level 1 (L1) dataset contains the Version 1.0 Climate Data Record (CDR) of the geo-located Delay Doppler Maps (DDMs) calibrated into Power Received (Watts) and Bistatic Radar Cross Section (BRCS) expressed in units of m2 from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. Other useful scientific and engineering measurement parameters include the DDM of Normalized Bistatic Radar Cross Section (NBRCS), the Delay Doppler Map Average (DDMA) of the NBRCS near the specular reflection point, and the Leading Edge Slope (LES) of the integrated delay waveform. The L1 dataset contains a number of other engineering and science measurement parameters, including sets of quality flags/indicators, error estimates, and bias estimates as well as a variety of orbital, spacecraft/sensor health, timekeeping, and geolocation parameters. At most, 8 netCDF data files (each file corresponding to a unique spacecraft in the CYGNSS constellation) are provided each day; under nominal conditions, there are typically 6-8 spacecraft retrieving data each day, but this can be maximized to 8 spacecraft under special circumstances in which higher than normal retrieval frequency is needed (i.e., during tropical storms and or hurricanes). Latency is approximately 2 months, depending on the availability of the MERRA wind speed reanalysis. The Version 1.0 CDR represents the first climate-quality release and is a collection of reanalysis products derived from the v2.1 Level 1 data. Calibration accuracy and long term stability are improved relative to the SDR v2.1 using a new trackwise correction algorithm which constrains the average value of the L1 data using MERRA-2 reanalysis wind speeds. Details of the algorithm are provide in the Trackwise Corrected CDR Algorithm Theoretical Basis Document. The CDR exhibits improved calibration accuracy and stability over v2.1. Trackwise correction is applied to the two primary CYGNSS L1 science data products the normalized bistatic radar cross section (NBRCS) and the leading edge slope of the Doppler-integrated delay waveform (LES). The correction compensates for variations in the transmit power level of the GPS signals measured by the CYGNSS bistatic radar receivers. By comparison, the v2.1 SDR L1 algorithm assumes a constant GPS transmit power, and variations in it can be misinterpreted as variations in the L1 data and in subsequent L2 science data products derived from them. The GPS constellation consists of several different satellite models (a.k.a. block types) and the level of transmit power variation differs between them. The more recent Block IIF models (which account for ~37% of the GPS constellation) have significantly larger variations than the older models and, for this reason, they have been screened out and not used to produce v2.1 L2 or L3 science data products. Trackwise correction eliminates the need for this screening so CDR L2 and L3 data products now include Block IIF samples. It should be noted that the trackwise correction algorithm cannot be successfully applied to all v2.1 SDR L1 data, so there is also some loss of samples that were present in v2.1. Overall, there is a significant increase in sampling and improvement in spatial coverage with the CDR products.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -40 -180 40 180

    POCLOUD Short Name: CYGNSS_L1_CDR_V1.0 Version ID: 1.0 Unique ID: C1996881862-POCLOUD

  • CYGNSS Level 1 Climate Data Record Version 1.1

    https://cmr.earthdata.nasa.gov/search/concepts/C2205121449-POCLOUD.xml
    Description:

    This Level 1 (L1) dataset contains the Version 1.1 Climate Data Record (CDR) of the geo-located Delay Doppler Maps (DDMs) calibrated into Power Received (Watts) and Bistatic Radar Cross Section (BRCS) expressed in units of m2 from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. Other useful scientific and engineering measurement parameters include the DDM of Normalized Bistatic Radar Cross Section (NBRCS), the Delay Doppler Map Average (DDMA) of the NBRCS near the specular reflection point, and the Leading Edge Slope (LES) of the integrated delay waveform. The L1 dataset contains a number of other engineering and science measurement parameters, including sets of quality flags/indicators, error estimates, and bias estimates as well as a variety of orbital, spacecraft/sensor health, timekeeping, and geolocation parameters. At most, 8 netCDF data files (each file corresponding to a unique spacecraft in the CYGNSS constellation) are provided each day; under nominal conditions, there are typically 6-8 spacecraft retrieving data each day, but this can be maximized to 8 spacecraft under special circumstances in which higher than normal retrieval frequency is needed (i.e., during tropical storms and or hurricanes). Latency is approximately 1 month, depending on the availability of the MERRA wind speed reanalysis. The Version 1.1 CDR is a collection of reanalysis products derived from the SDR v3.0 Level 1 data (https://doi.org/10.5067/CYGNS-L1X30 ). Calibration accuracy and long term stability are improved relative to SDR v3.0 using the same trackwise correction algorithm as was used by CDR v1.0 (https://doi.org/10.5067/CYGNS-L1C10 ), which was derived from SDR v2.1 Level 1 data (https://doi.org/10.5067/CYGNS-L1X21 ). Details of the algorithm are provided in the Trackwise Corrected CDR Algorithm Theoretical Basis Document. Trackwise correction is applied to the two primary CYGNSS L1 science data products, the normalized bistatic radar cross section (NBRCS) and the LES. The correction compensates for small errors in the Level 1 calibration, due e.g. to uncertainties in the GPS transmitting antenna gain patterns and the CYGNSS receiving antenna gain patterns. It should be noted that the trackwise correction algorithm cannot be successfully applied to all v3.0 SDR L1 data, so there is also some loss of samples that were present in v3.0.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -40 -180 40 180

    POCLOUD Short Name: CYGNSS_L1_CDR_V1.1 Version ID: 1.1 Unique ID: C2205121449-POCLOUD

  • CYGNSS Level 1 Climate Data Record Version 1.2

    https://cmr.earthdata.nasa.gov/search/concepts/C2274919541-POCLOUD.xml
    Description:

    This Level 1 (L1) dataset contains the Version 1.2 Climate Data Record (CDR) of the geo-located Delay Doppler Maps (DDMs) calibrated into Power Received (Watts) and Bistatic Radar Cross Section (BRCS) expressed in units of m2 from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. Other useful scientific and engineering measurement parameters include the DDM of Normalized Bistatic Radar Cross Section (NBRCS), the Delay Doppler Map Average (DDMA) of the NBRCS near the specular reflection point, and the Leading Edge Slope (LES) of the integrated delay waveform. The L1 dataset contains a number of other engineering and science measurement parameters, including sets of quality flags/indicators, error estimates, and bias estimates as well as a variety of orbital, spacecraft/sensor health, timekeeping, and geolocation parameters. At most, 8 netCDF data files (each file corresponding to a unique spacecraft in the CYGNSS constellation) are provided each day; under nominal conditions, there are typically 6-8 spacecraft retrieving data each day, but this can be maximized to 8 spacecraft under special circumstances in which higher than normal retrieval frequency is needed (i.e., during tropical storms and or hurricanes). Latency is approximately 1 week. The Version 1.2 CDR is a collection of reanalysis products derived from the SDR v3.1 Level 1 data (https://doi.org/10.5067/CYGNS-L1X31 ). Calibration accuracy and long term stability are improved relative to SDR v3.0 using the same trackwise correction algorithm as was used by CDR v1.1 (https://doi.org/10.5067/CYGNS-L1C11 ), which was derived from SDR v2.1 Level 1 data (https://doi.org/10.5067/CYGNS-L1X21 ). Details of the algorithm are provided in the Trackwise Corrected CDR Algorithm Theoretical Basis Document. Trackwise correction is applied to the two primary CYGNSS L1 science data products, the normalized bistatic radar cross section (NBRCS) and the LES. The correction compensates for small errors in the Level 1 calibration, due e.g. to uncertainties in the GPS transmitting antenna gain patterns and the CYGNSS receiving antenna gain patterns. It should be noted that the trackwise correction algorithm cannot be successfully applied to all v3.1 SDR L1 data, so there is also some loss of samples that were present in v3.1.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -40 -180 40 180

    POCLOUD Short Name: CYGNSS_L1_CDR_V1.2 Version ID: 1.2 Unique ID: C2274919541-POCLOUD

  • CYGNSS Level 1 Full Delay Doppler Map Data Record

    https://cmr.earthdata.nasa.gov/search/concepts/C2036882030-POCLOUD.xml
    Description:

    This Level 1 (L1) dataset contains the Full Delay Doppler Map (DDM) sensor data from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. The primary CYGNSS instrument, also known as the Delay-Doppler Mapping Instrument (DDMI), measures the incoming radio frequency (RF) streams from three input antenna channels (2 nadir oriented science antennas and one zenith oriented navigation antenna) and processes them in real time into DDMs, which are two-dimensional maps of the signal scattered from the Earth surface as a function of propagation time delay and Doppler frequency shift. DDMs are normally sampled over a restricted range of delay and Doppler values centered on the values at the specular point of reflection. The bit resolution of scattered signal strength is also truncated by a lossy data compression algorithm. Full DDMs are sampled over a wider range of delay and Doppler values and retain their full (lossless) bit resolution. Full DDM data records are typically 10-15 min in duration and are initiated by ground commands to coincide with an overpass by one of the spacecraft of a target area of interest.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -40 -180 40 180

    POCLOUD Short Name: CYGNSS_L1_FULL_DDM Version ID: 1.0 Unique ID: C2036882030-POCLOUD

  • CYGNSS Level 1 Full Delay Doppler Map Data Record Version 3.0

    https://cmr.earthdata.nasa.gov/search/concepts/C2205121474-POCLOUD.xml
    Description:

    This Level 1 (L1) dataset contains the Version 3.0 (v3.0) Full Delay Doppler Map (DDM) sensor data from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. The primary CYGNSS instrument, also known as the Delay-Doppler Mapping Instrument (DDMI), measures the incoming radio frequency (RF) streams from three input antenna channels (2 nadir oriented science antennas and one zenith oriented navigation antenna) and processes them in real time into DDMs, which are two-dimensional maps of the signal scattered from the Earth surface as a function of propagation time delay and Doppler frequency shift. DDMs are normally sampled over a restricted range of delay and Doppler values centered on the values at the specular point of reflection. The bit resolution of scattered signal strength is also truncated by a lossy data compression algorithm. Full DDMs are sampled over a wider range of delay and Doppler values and retain their full (lossless) bit resolution. Full DDM data records are typically 10-15 min in duration and are initiated by ground commands to coincide with an overpass by one of the spacecraft of a target area of interest. This version supersedes the Full DDM Version 1.0 (https://doi.org/10.5067/CYGNS-L1FDD) for data retrieved during or after August 2018. For data retrieved prior to August 2018, users will need to continue using the Full DDM Version 1.0. This version links the Full DDMs to the CYGNSS v3.0 L1 files (https://doi.org/10.5067/CYGNS-L1X30) whereas the version 1.0 Full DDM linked the Full DDMs to the CYGNSS v2.1 L1 files (https://doi.org/10.5067/CYGNS-L1X21). The calibration of the Full DDMs has not been modified for this release.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -40 -180 40 180

    POCLOUD Short Name: CYGNSS_L1_FULL_DDM_V3.0 Version ID: 3.0 Unique ID: C2205121474-POCLOUD

  • CYGNSS Level 1 Raw Intermediate Frequency Data Record

    https://cmr.earthdata.nasa.gov/search/concepts/C2036882037-POCLOUD.xml
    Description:

    This Level 1 (L1) dataset contains the Raw Intermediate Frequency (IF) sensor data from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. The primary CYGNSS instrument, also known as the Delay-Doppler Mapping Instrument (DDMI), digitizes the incoming radio frequency (RF) streams from three input antenna channels (2 nadir oriented science antennas and one zenith oriented navigation antenna). The Raw IF data included in this data record are the raw sensor counts, retrieved prior to any digital signal processing, thus providing the highest possible resolution in delay and doppler space allowing for the construction of high resolution Delay Doppler Map (DDM) data. Raw IF data records are 30-90 sec in duration, with 60 sec being typical, and are initiated by ground commands to coincide with an overpass by one of the spacecraft of a target area of interest.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -40 -180 40 180

    POCLOUD Short Name: CYGNSS_L1_RAW_IF Version ID: 1.0 Unique ID: C2036882037-POCLOUD

  • CYGNSS Level 1 Science Data Record Version 2.1

    https://cmr.earthdata.nasa.gov/search/concepts/C2251464384-POCLOUD.xml
    Description:

    This Level 1 (L1) dataset contains the Version 2.1 geo-located Delay Doppler Maps (DDMs) calibrated into Power Received (Watts) and Bistatic Radar Cross Section (BRCS) expressed in units of meters squared from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. This version supersedes Version 2.0. Other useful scientific and engineering measurement parameters include the DDM of Normalized Bistatic Radar Cross Section (NBRCS), the Delay Doppler Map Average (DDMA) of the NBRCS near the specular reflection point, and the Leading Edge Slope (LES) of the integrated delay waveform. The L1 dataset contains a number of other engineering and science measurement parameters, including sets of quality flags/indicators, error estimates, and bias estimates as well as a variety of orbital, spacecraft/sensor health, timekeeping, and geolocation parameters. At most, 8 netCDF data files (each file corresponding to a unique spacecraft in the CYGNSS constellation) are provided each day; under nominal conditions, there are typically 6-8 spacecraft retrieving data each day, but this can be maximized to 8 spacecraft under special circumstances in which higher than normal retrieval frequency is needed (i.e., during tropical storms and or hurricanes). Latency is approximately 6 days (or better) from the last recorded measurement time. The Version 2.1 release represents the second science-quality release. Here is a summary of improvements that reflect the quality of the Version 2.1 data release: 1) data is now available when the CYGNSS satellites are rolled away from nadir during orbital high beta-angle periods, resulting in a significant amount of additional data; 2) correction to coordinate frames result in more accurate estimates of receiver antenna gain at the specular point; 3) improved calibration for analog-to-digital conversion results in better consistency between CYGNSS satellites measurements at nearly the same location and time; 4) improved GPS EIRP and transmit antenna pattern calibration results in significantly reduced PRN-dependence in the observables; 5) improved estimation of the location of the specular point within the DDM; 6) an altitude-dependent scattering area is used to normalize the scattering cross section (v2.0 used a simpler scattering area model that varied with incidence and azimuth angles but not altitude); 7) corrections added for noise floor-dependent biases in scattering cross section and leading edge slope of delay waveform observed in the v2.0 data. Users should also note that the receiver antenna pattern calibration is not applied per-DDM-bin in this v2.1 release.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -40 -180 40 180

    POCLOUD Short Name: CYGNSS_L1_V2.1 Version ID: 2.1 Unique ID: C2251464384-POCLOUD

  • CYGNSS Level 1 Science Data Record Version 3.0

    https://cmr.earthdata.nasa.gov/search/concepts/C2205618435-POCLOUD.xml
    Description:

    This Level 1 (L1) dataset contains the Version 3.0 geo-located Delay Doppler Maps (DDMs) calibrated into Power Received (Watts) and Bistatic Radar Cross Section (BRCS) expressed in units of m2 from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. This version supersedes Version 2.1; https://doi.org/10.5067/CYGNS-L1X21 . Other useful scientific and engineering measurement parameters include the DDM of Normalized Bistatic Radar Cross Section (NBRCS), the Delay Doppler Map Average (DDMA) of the NBRCS near the specular reflection point, and the Leading Edge Slope (LES) of the integrated delay waveform. The L1 dataset contains a number of other engineering and science measurement parameters, including sets of quality flags/indicators, error estimates, and bias estimates as well as a variety of orbital, spacecraft/sensor health, timekeeping, and geolocation parameters. At most, 8 netCDF data files (each file corresponding to a unique spacecraft in the CYGNSS constellation) are provided each day; under nominal conditions, there are typically 6-8 spacecraft retrieving data each day, but this can be maximized to 8 spacecraft under special circumstances in which higher than normal retrieval frequency is needed (i.e., during tropical storms and or hurricanes). Latency is approximately 6 days (or better) from the last recorded measurement time. Here is a summary of improvements the calibration and processing changes to the Version 3.0 data: 1) the transmitted GPS signal strength in the direction of the DDM scattering surface is determined in real time from measurements of the direct signal from the GPS satellite to the CYGNSS navigation receiver, allowing for the BRCS calibration to be corrected for variations in GPS transmit power; 2) the NBRCS has been validated using comparisons with a large population of modeled values derived from coincident ocean surface roughness spectra produced by the NOAA WAVEWATCH-3 oceanographic wave model; 3) L1 calibration parameters have been adjusted to produce a best fit to the model population.

    Links: Temporal Extent: Spatial Extent:
    Minimum Bounding Rectangle: -40 -180 40 180

    POCLOUD Short Name: CYGNSS_L1_V3.0 Version ID: 3.0 Unique ID: C2205618435-POCLOUD