Aquarius Radio Frequency Interference (RFI) Ancillary Dataset V1.0
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DescriptionAquarius ancillary Radio Frequency Interference (RFI) product used in ADPS mission processing contains monthly-averaged Radio Frequency Interference (RFI) data for ascending/descending passes as detected by the Aquarius radiometers and scatterometer. The data is available for ascending (northward) and descending (southward) passes of the satellite only and ascending/descending passes combined. The values stored in this product are the percentage of radiometer and scatterometer measurements identified as corrupted by interference by the RFI detection algorithms [1,2] within each data point, averaged over one month. An additional RFI flag [3] is used to identify locations where the measured brightness temperature over land exceeds the expected limits of surface emissivity. This flag is not used to remove samples from further processing, but, in generating the radiometer RFI data, 100% RFI is assigned to points where this flag is raised. This product can be used to reproduce the RFI maps available on the Aquarius website at University of Maine ( for the radiometer, and for the scatterometer), by plotting the variables Rad_RFI_percent_AscDes_AllBeams and Scat_RFI_percent_AscDes_AllBeams on the latitude/longitude grid. Additionally, the user can generate maps by using only a particular beam or only ascending passes, for example. All combinations of beams and ascending/descending passes are possible. This product contains information about RFI, but it is also relevant for the retrieved Sea Surface Salinity (SSS). Over the ocean, the RFI percentage in this product corresponds to the amount of raw measurements discarded due to RFI contamination before SSS retrieval. Therefore, maps of the RFI percentage can give the user an indication of where RFI is more likely to have affected the quality of SSS retrievals, for a particular month, or for a series of months.
Dataset TypeOPEN
Processing Level3
CoverageRegion: Global
Northernmost Latitude: 90 degrees
Southernmost Latitude: -90 degrees
Westernmost Longitude: -180 degrees
Easternmost Longitude: 180 degrees
Time Span: 2011-Sep-01 to 2015-Jun-01
Granule Time Span: 2011-Sep-01 to 2015-Jun-01
ResolutionSpatial Resolution: 1 degrees (Latitude) x 1 degrees (Longitude)
Temporal Resolution: 1 Month
ProjectionType: Gridded
Ellipsoid: WGS 84
Latency720 hours
Name: Aquarius SAC-D (Aquarius_SAC-D)
Orbit Period: 98 minutes
Inclination Angle: 98 degrees
Ascending Node: 1970-Jan-01 00:00:00
Name: Aquarius Radiometer (AQUARIUS_RADIOMETER)
Swath Width: 390 km
Description: Launched in 2011 the 3 Aquarius radiometers meet very exacting requirements for low noise and calibration stability. This makes them about an order of magnitude more accurate than any radiometer ever used before for remote sensing of the earth. Aquarius measures in the microwave range at 1.413 GHz (+/- 25MHz).

Name: Aquarius SAC-D (Aquarius_SAC-D)
Orbit Period: 98 minutes
Inclination Angle: 98 degrees
Ascending Node: 1970-Jan-01 00:00:00
Name: Aquarius Scatterometer (AQUARIUS_SCATTEROMETER)
Swath Width: 390 km
Description: The Aquarius scatterometer is a total-power L-band (1.26 GHz)radar system for estimating ocean surface roughness. Itsmeasurements will enable the removal of wind effects from theAquarius radiometer ocean-surface brightness temperaturemeasurements being used to retrieve ocean salinity. TheAquarius scatterometer is a relatively simple, low-spatialresolution power-detecting radar, without ranging capability.But to meet its science requirement, it must be very stable, withrepeatability on the order of 0.1 dB over several days, andcalibrated accuracy to this level over several months. Datafrom this instrument over land as well as ocean areas will beavailable for a variety of geophysical applications.

Data ProviderCreator: Yan Soldo, Paolo De Matthaeis, David Levine
Release Place: Goddard Space Flight Center, 8800 Greenbelt Rd.; Greeenbelt, Md., 20771
Release Date: 2018-Jan-30
Keyword(s)Aquarius, polar, sun-synchronous, RFI, Radio Frequency Interference, CONAE, argentina
Persistent IDPODAAC-AQR00-RFI01
Questions related to this dataset? Contact
User's Guide
User's Guide
Aquarius RFI Product User's Guide
Additional Sites
Aquarius/SAC-D Mission Website
NASA Aquarius/SAC-D mission website
Citation Yan Soldo, Paolo De Matthaeis, David Levine. 2018. Aquarius Radio Frequency Interference (RFI) Ancillary Dataset V1.0. Ver. 1. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at

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