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Description

Aquarius 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 (https://aquarius.umaine.edu/cgi/gal_radiometer.htm for the radiometer, and https://aquarius.umaine.edu/cgi/gal_scatterometer.htm 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.

Product Summary

Platforms
SAC-D
Instruments
AQUARIUS_RADIOMETER
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2011-09-01 to 2015-06-01
Data Partner
AQUARIUS, Jet Propulsion Laboratory, NASA (NASA/JPL/AQUARIUS) ,
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C2617176765-POCLOUD
Data State
COMPLETE
Number of Files/Granules
45
Processing Level
3
Published
Updated
Science Keywords
Salinity

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

NASA/GSFC. (2018). Aquarius Radio Frequency Interference (RFI) Ancillary Dataset V1.0 [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/AQR00-RFI01 Date Accessed: 2025-12-13

Documents

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
/Radiometer/Rad_RFI_percent_Asc Percent of radiometer samples flagged as RFI (individual beams; ascending passes only) % float -9999 0 to 100 1
/Radiometer/Rad_RFI_percent_AscDes Percent of radiometer samples flagged as RFI (individual beams) % float -9999 0 to 100 1
/Radiometer/Rad_RFI_percent_AscDes_AllBeams Percent of radiometer samples flagged as RFI (individual beams) % float -9999 0 to 100 1
/Radiometer/Rad_RFI_percent_Asc_AllBeams Percent of radiometer samples flagged as RFI (all beams combined; ascending passes only) % float -9999 0 to 100 1
/Radiometer/Rad_RFI_percent_Des Percent of radiometer samples flagged as RFI (individual beams; descending passes only) % float -9999 0 to 100 1
/Radiometer/Rad_RFI_percent_Des_AllBeams Percent of radiometer samples flagged as RFI (all beams combined; descending passes only) % float -9999 0 to 100 1
/Scatterometer/Scat_RFI_percent_Asc Percent of scatterometer samples flagged as RFI (individual beams; ascending passes only) % float -9999 0 to 100 1
/Scatterometer/Scat_RFI_percent_AscDes Percent of scatterometer samples flagged as RFI (individual beams) % float -9999 0 to 100 1
/Scatterometer/Scat_RFI_percent_AscDes_AllBeams Percent of scatterometer samples flagged as RFI (all beams combined) % float -9999 0 to 100 1
/Scatterometer/Scat_RFI_percent_Asc_AllBeams Percent of scatterometer samples flagged as RFI (all beams combined; ascending passes only) % float -9999 0 to 100 1
/Scatterometer/Scat_RFI_percent_Des Percent of scatterometer samples flagged as RFI (individual beams; descending passes only) % float -9999 0 to 100 1
/Scatterometer/Scat_RFI_percent_Des_AllBeams Percent of scatterometer samples flagged as RFI (all beams combined; descending passes only) % float -9999 0 to 100 1
Latitude Latitude degrees_north float -9999 -90 to 90 1
Longitude Longitude degrees_east float -9999 -180 to 180 1
Time Time seconds since 2000-01-01T12:00:00.000Z double N/A 360936000 to 486993600 1
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