Version 1
  • Abstract
    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 m2 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.

Data Identification Fields:

Toggle Data Identification Fields
    Data Dates
    Last Revision
    Processing Level


    Collection Progress

    Not Provided

Related URLs
    Science Keywords
    • Earth Science
    • Spectral/Engineering
    • Radar
    • Radar Cross-section
    • Bistatic Radar Cross-Section
    • Earth Science
    • Spectral/Engineering
    • Radar
    • Radar Reflectivity
    • Zenith Signal Power

Acquisition Information Fields:

Toggle Acquisition Information Fields
    • DDMI

Temporal Information Fields:

Toggle Temporal Information Fields

Spatial Information Fields:

Toggle Spatial Information Fields
    Coverage Type Zone Identifier Geometry Granule Representation
Location Keywords
    • GLOBAL

Data Centers

Toggle Data Centers

    This data center does not have any addresses listed.

    This data center does not have any contact mechanisms listed.


    This data center does not have any addresses listed.

    This data center does not have any contact mechanisms listed.

  • Cyclone Global Navigation Satellite System

    This data center does not have any addresses listed.

Data Contacts

Toggle Data Contacts
  • Tim Butler
    Technical Contact
    Tim Butler

    Cyclone Global Navigation Satellite System

    This contact does not have any addresses listed.

    This contact does not have any contact mechanisms listed.

Collection Citations Fields:

Toggle Collection Citations Fields

Archive And Distribution Information Fields:

Toggle Archive And Distribution Information Fields
    File Distribution Information
    • NETCDF

      Format Type: Native