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Description

The Global River Radar Altimeter Time Series (GRRATS) 1km/daily interpolations are river heights from ERS-1, ERS-2, TOPEX/Poseidon OSTM/Jason-2 and Envisat that are interpolated and processed to create a continuous heights for the study over the temporal range of the altimeters used. The purpose of these heights are to provide satellite altimetric river height data in a form that is more recognizable to the observational community and as a way to get users use to using satellite data for river hydrology. These pre SWOT data are derived from satellites to provide hydrological measurements. The Surface Water and Ocean Topography (SWOT) mission will have hydrology as one of its objectives. This dataset does not have the same variables as SWOT, but does provide hydrological measurements with typical quality flagging typical of satellite data. Not only does it provide science information, it can also assist hydrological users new to satellite data with the satellite data formats and variables before SWOT launches.

Product Summary

Platforms
OSTM/JASON-2 ,
TOPEX/POSEIDON ,
ENVISAT ,
JASON-3 ,
JASON-1 ,
ERS-2
Instruments
POSEIDON-3 ,
ALT (TOPEX) ,
RA-2 ,
POSEIDON-3B ,
POSEIDON-2 ,
ALTIMETERS
Spatial Extent

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

Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
1992-04-06 to 2018-04-20
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C2036882359-POCLOUD
Data State
COMPLETE
Number of Files/Granules
26
Processing Level
2
Published
Updated
Science Keywords
Surface Water Features

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

Coss, S., Durand, M., Lettenmaier, D., Yi, Y., Jia, Y., Guo, Q., Shun, C. K., Allen, G. H., Calmant, S., & Pavelsky, T. (2019). Pre SWOT Hydrology GRRATS Daily River Heights and Storage Version 2 [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/PSGRA-DA2V2 Date Accessed: 2026-03-15

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
/Ice_Pass/height_ip A time flow distance grid of river water heights with respect to the EGM08 Geoid).-9999 fill values are for missing data, while -9995 fill values are for lakes and reservoirs.This version was processed with GRRATS data without ice dates flagged and removed. m double -9999 -3.4419319340904 to 77.713403774481 1 N/A
/Ice_Pass/IceFlag This is a flag for masking out times of Ice Cover. N/A double -9999 N/A 1 N/A
/Ice_Pass/storage_ip A time flow distance grid of river channel storage values. This version was processed with GRRATS river surface elevation data without ice dates flagged and removed. km3 double -9999 N/A 1 N/A
/Ice_Pass/Storage_uncertainty_ip A time flow distance grid of river channel storage uncertainty values. This version was processed with GRRATS river surface elevation data without ice dates flagged and removed. km3 double -9999 N/A 1 N/A
FD This is the distance along the river centerline from the river mouth to this VS. km double N/A N/A 1 N/A
height A time flow distance grid of river water heights with respect to the EGM08 Geoid).-9999 fill values are for missing data, while -9995 fill values are for lakes and reservoirs. m double -9999 -3.4419319340904 to 77.713403774481 1 N/A
IceFlag This is a flag for masking out times of Ice Cover. N/A double -9999 N/A 1 N/A
LakeFlag This is a flag for masking out setions that are lakes or reservoirs. N/A double -9999 N/A 1 N/A
lat latitude degrees_north double N/A N/A 1 N/A
lon longitude degrees_east double N/A N/A 1 N/A
storage A time flow distance grid of river channel storage values. km3 double -9999 N/A 1 N/A
Storage_uncertainty A time flow distance grid of river channel storage uncertainty values. km3 double -9999 N/A 1 N/A
time time days since 1901-01-01T00:00:00 double N/A N/A 1 N/A
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