NASA/ISRO (Indian Space Research Organization) Synthetic Aperture Radar

Observations from the joint NASA/ISRO (Indian Space Research Organization) Synthetic Aperture Radar (NISAR) satellite mission provides new opportunities for monitoring changes occurring in Earth’s ecosystems, cryosphere, vegetation, sea level, groundwater, and natural hazards.

Learn more about NISAR

Type

Earth Observation Satellite

Data Center

ASF DAAC

Launch

July 30, 2025

Objective

Observe and measure changes on Earth's surface

The NISAR Science Users’ Handbook was first published in 2019 and provided an introduction to many of the mission science and applications objectives. The second edition of the handbook was released in October 2025. It reflects the evolution of all aspects of the mission leading up to the successful launch of the satellite in July 2025, and provides new information and expanded descriptions of the many science and applications enabled by NISAR.

Access the NISAR Science Users’ Handbook

NASA and the Indian Space Research Organization (ISRO) each provide SAR instruments, at two different radar frequencies, to measure changes on Earth's surface in unprecedented detail.

Learn more about NASA's partnership with ISRO

The NISAR Science Data System (SDS) team will generate the L-Band Level 0, Level 1, and Level 2 products; the NISAR Project Science and Science Teams will generate the Level 3 products.

Product	Product Description
RRSD (Radar Raw Signal Data)	Level 0 unfocused raw SAR data
RSLC (Range-Doppler Single Look Complex)	Level 1 Focused SAR image in range-doppler coordinates (zero-doppler steered)
RIFG (Range-Doppler Wrapped Interferogram)	Level 1 phase-wrappted interferogram in range-doppler coordinates (zero-doppler steered)
RUNW (Range-Doppler Interferogram)	Level 1 phase-unwrapped interferogram in range-doppler coordinates (zero-doppler steered)
ROFF (Range-Doppler Pixel Offsets)	Level 1 pixel offsets in range-doppler coordinates (zero-doppler steered)
GSLC (Geocoded Single Look Complex)	Level 2 Focused SAR image in geocoded coordinates
GUNW (Geocoded Interferogram)	Level 2 phase-unwrapped interferogram in geocoded coordinates
GOFF (Geocoded Pixel Offsets)	Level 2 pixel offsets in geocoded coordinates
GCOV (Geocoded Polarimetric Covariance)	Level 2 SAR covariance product in geocoded coordinates
SM (Soil Moisture EASE-Grid 2.0)	Level 3 Global Soil Moisture Product
ECMWF SMST (Ancillary Data)	Subset of ECMWF products used for the creation of NISAR products
ECMWF TROPO (Ancillary Data)	Subset of ECMWF products used for the creation of NISAR products

ASF DAAC provides access to sample NISAR datasets, allowing the community to explore data formats, test workflows, and prepare tools ahead of the mission’s full release. Sample products are available to give users the opportunity to become familiar with NISAR data and integrate it into their applications.

Chart showing anticipated NISAR products with L0 on left and L3-4 on right

NISAR data product levels. Products through Level 2 will be produced for the entire mission dataset. Products at higher levels will be produced by the science team for calibration and validation purposes. Credit: NISAR Mission Science Users' Handbook, August 2019, Version 1.

Composite Release ID Table (CRID)

A Composite Release ID (CRID) is a unique identifier to provide provenance of the aggregate software and static input file versions used in the generation of a product granule.

CRID	Release Date	Manifest (.csv)	Notes
P05000	Oct 16, 2025 13:06:00 UTC	Download NISAR_LSAR_CRID_P05000.csv	Updated TFdb (TrackFrame Database) Update L0A_TE to exit gracefully if all L0A data is corrupt Update RSLC to address large number of RSLC failures Update RSLC NESZ explicit receive only Angeline index Update GSLC to accept corner reflector Update GCOV for bug fixes and improve GCOV products in Quad-pol modes Update INSAR to add radar coordinates into products and improve ionosphere estimation Update INSAR metadata Update SME2 for bug fix of VWC input order, antimeradian crossing, private variable bug Update SME2 to compute Local Incidence angle on the fly at coarser posting than input GCOV product Update SME2 with TSR algorithm update with solver function for better solution space control, SMAP climatology data disaggregation using soil texture information, changed the condition for masking, and etc. to improve the output image quality. Update SME2 with DSG algorithm update with a static ancillary file input to read in the algorithm parameter (Beta) values instead of using a look up table. Note: The Beta values in the LUT is not optimal and will need to be updated in the future. Update SME2 to use the full name of the processing Type metadata in the product NISAR L1/L2 QA fixes
P00410	Sept 9, 2025 10:39:00 UTC	Download NISAR_LSAR_CRID_P004010.csv	Update L0B PGE code to remove .h5 from granuleId under identification group Update L0B to correctly set listOfRxPolarizations for partial Quasi QuadCorrect look direction case-sensitivity and platformName value Update L0B look direction algorithm to set the epoch for both the orbit and attitude Update L0B to not use SP because Header-only values are not correct for SP Update L0B to for DM1/DM2 to remove RL_START dependency for slant_range and padding, also handle change in DM2 number of samples Update L0B to address Frequency B alignment issues Added padding parameters for the gap positions in L0B runconfig Add filter delay and receive_only parameters as optional parameters in L0B runconfig Update L0B productSpecificationVersion to match PIX XML version Update L0B to create multipolygon in met for non self intersecting polygons over international data line (IDL) to allow DAAC to interpret granule location correctly over IDL
P00408	Aug 16, 2025 00:00:00 UTC	Download NISAR_LSAR_CRID_P00408.csv	Hi-Res Range-Doppler Single-Look Complex (RSLC) update for phase jumps L0B update for phase jump and 4th gaps DC_RADAR updates to support variable taps in DBF along the range line and to update antenna parser to allow finer Elevation/Azimuth (EL/AZ) angular spacing when their cuts over all channels are requested
P00407	July 30, 2025 00:00:00 UTC	Download NISAR_LSAR_CRID_P00407.csv	Launch release

Glossary of Terms - Click on the arrow to open a table describing terminology used

Item Name	Item Type	Item Description
CRID	Composite Release ID	Composite Release ID (CRID) is a unique identifier to provide provenance of the aggregate software and static input file versions listed in generation of a product granule
SDS	SDS release	Science Data System (SDS) version used to generate given product.
PCM	PCM SW	Processing Control & Data Management Subsystem (PCM) used to orchestrate product generation within a given SDS
L0A_L_PGE	PGE SW	Product Generation Executable (PGE) version of L0A_L_PGE
L0A_CC	PGE SW	Product Generation Executable (PGE) version of L0A_CC
L0A_TE	PGE SW	Product Generation Executable (PGE) version of L0A_TE
L0A_CC_TE	PGE SW	Product Generation Executable (PGE) version of L0A_CC_TE
LSAR_Time_Extractor	PGE SW	Product Generation Executable (PGE) version of LSAR_Time_Extractor
L0B_L_PGE	PGE SW	Product Generation Executable (PGE) version of L0B_L_PGE
RSLC_L_PGE (l1_l2)	PGE SW	Product Generation Executable (PGE) version of RSLC_L_PGE
GSLC_L_PGE (l1_l2)	PGE SW	Product Generation Executable (PGE) version of GSLC_L_PGE
L2_L_GCOV (l1_l2)	PGE SW	Product Generation Executable (PGE) version of L2_LGCOV
InSAR_L_PGE (l1_l2)	PGE SW	Product Generation Executable (PGE) version of L2_InSAR_L_PGE
L3_L_SME2_PGE	PGE SW	Product Generation Executable (PGE) version of L3_L_SME2_PGE
DC_RADAR_PGE	PGE SW	Product Generation Executable (PGE) version of DC_RADAR_PGE
ISCE3 (l0b)	ISCE3 SW	Algorithm version in l0b pge
ISCE3 (l1_l2)	ISCE3 SW	Algorithm version in l1_l2 pges
ISCE3 (SME2)	ISCE3 SW	Algorithm version in SME2_pge
ISCE3 (DC_RADAR)	ISCE3 SW	Algorithm version in DC_RADAR_pge
L0A_L_RRST	Product Version	Product version of generated L0A_L_RRST product
L0B_L_RRSD	Product Version	Product version of generated L0B_L_RRSD product
L1_L_RSLC	Product Version	Product version of generated L1_L_RSLC product
L2_L_GSLC	Product Version	Product version of generated L2_L_GSLC product
L2_L_GCOV	Product Version	Product version of generarted L2_L_GCOV product
L1_L_RIFG	Product Version	Product version of generated L1_L_RIFG product
L1_L_RUNW	Product Version	Product version of generated L1_L_RUNW product
L1_L_ROFF	Product Version	Product version of generated L1_L_ROFF product
L2_L_GOFF	Product Version	Product version of generated L2_L_GOFF product
L2_L_GUNW	Product Version	Product version of generated L2_L_GUNW product
DC_RADAR	Product Version	Product version of generated DC_RADAR product
L3_L_SME2	Product Version	Product version of generated L3_L_SME2 product
PRODUCT_VERSION	Static File	PRODUCT_VERSION file used by SDS to lookup Product Version for a given CRID and PGE, which is then populated in metadata of the product
LSAR Parameter Set	Static File	LSAR Parameter Set used by SDS to help populate runconfigs at runtime for a given product by specifying processing parameters for a PGE
DEM	Static File	Digital Elevation Model (DEM) file set is digital representation of terrain elevation for the NASA-ISRO NISAR mission used by RSLC_L_PGE, GSLC_LPGE, L2_L_GCOV, InSAR_L_PGE, and DC_RADAR_PGE. - EPSG 4326 is based on the Copernicus DEM 30-m (2023_1). - EPSG 3413 is based on the Copernicus DEM 30-m (2023_1), referenced to the WGS84 ellipsoid and projected over the NSIDC Sea Ice Polar Stereographic North coordinate system. - EPSG 3031 is based on the Copernicus DEM 30-m (2023_1), referenced to the WGS84 ellipsoid and projected over the Antarctic Polar Stereographic coordinate system.
LIA	Static File	Local Incidence Angle (LIA) version set used by the SDS to generate SME2 products. A copy of this LIA data is embedded in the L2_L_STATIC set for convenience for users to find all static layers in one location.
Water Mask	Static File	Water Mask version set used by the SDS to generate RUNW/GUNW products. A copy of this water mask data is embedded in the L2_L_STATIC set for convenience for users to find all static layers in one location.
VWC	Static File	Vegetation Water Content (VWC) version set used by the SDS to generate SME2 products.
L2_L_STATIC	Static File	L2_L_STATIC version used to provide static layer content matching the geographical area of a product in a single convenient .h5 file for the user. Static layer content includes: - digitalElevationModel - layoverShadowMask - localIncidenceAngle - losUnitVectorX - losUnitVectorY - projection - rtcGammaToBetaFactor - rtcGammaToSigmaFactor - waterMask
TFDB	Static File	TFDB version used by the SDS to generate RSLC products. The TFDB specifies the collection modes of the observations around over the globe, which is delineated by track and frame number in the database.
RADAR_MODE_LUT	Static File	RADAR_MODE_LUT version used by PCM to map RCID to Radar Mode short text populated in filename of RSLC product
Flight Table Waveform	Static File	Flight Table Waveform version used by L0B_L_PGE
Flight Table Parameters	Static File	Flight Table Parameters version used by L0B_L_PGE
ANTPAT	Static File	ANTPAT file used by the SDS to generate RSLC_L_PGE and DC_RADAR_PGE products.
BFPQ	Static File	ANTPAT file used by the SDS to generate L0B_L_PGE
L_CHAN_DATA	Static File	ANTPAT file used by the SDS to generate L0B_L_PGE
LSAR_EXT_CAL	Static File	LSAR_EXT_CAL version used by RSLC_L_PGE
LSAR_INT_CAL	Static File	LSAR_INT_CAL version used by RSLC_L_PGE
TSR_STATIC	Static File	TSR_STATIC used by L3_L_SME2
PMI_STATIC	Static File	PMI_STATIC used by L3_L_SME2
SM_STATIC	Static File	SM_STATIC used by L3_L_SME2

L-Band: 1.25 GHz; 24 cm wavelength; polarimetric SAR

SP: HH or VV
DP: HH/HV or VV/VH
CP: RH/RV
QP (Quad Pol): HH/HV/VH/VV

S-Band: 3.20 GHz; 12 cm wavelength; polarimetric SAR

SP (Single Pol): HH or VV
DP (Dual Pol): HH/HV or VV/VH
CP (Compact Pol): RH/RV
QQP (Quasi-Quad Pol):HH/HV and VH/VV

Parameters	S-Band	L-Band
Orbit	747 km with 98° inclination
Repeat Cycle	12 days
Time of Nodal Crossing	6 a.m./6 p.m.
Frequency	3.2 GHz ± 37.5 MHz	1.257 GHz ± 40 MHz
Available Polarmetric Modes	Single Pol (SP): H or VV Dual Pol (DP: HH/HV or VV/VH Compact Pol (CP): RH/RV Quasi-Quad Pol (QQP): HH/HV and VH/VV	SP: HH or VV DP: HH/HV or VV/VH CP: RH/RV Quad Pol (QP): HH/HV/VH/VV
Available Range Bandwidths	10 MHz, 25 MHz, 37.5 MHz, 75 MHz	5 MHz, 20 MHz, 40 MHz, 80 MHz (additional 5 MHz iono band for 20 and 40 MHz modes at other end of pass-band)
Swath Width	>240 Km (except for QQP mode)	>240 Km (except for 80 MHz BW)
Spatial Resolution	7 m (Az); 3 m - 24 m (Slant-Ra)	7 m (Az); 3 m - 48 m (Slant-Ra)
Incidence Angle Range	37-47 deg	37-47 deg
Noise Equivalent	-25 dB (baseline) -20 dB (threshold)	-25 dB (for required full-swath modes)
Ambiguities	<-20 dB for all modes except QQP	<-23 dB swath average in SP or DP modes <-17 dB swath average in QP modes
Data Product Access	Free and Open

Schematics

Schematic explanation of file naming convention for the NISAR RRST products: NISAR_IL_PROD_VCID_StartDateTime_EndDateTime_CRID_LOC_CTR.ext

Acronyms represent: Mission, Beam Mode, Processing Level, Product Identifier, Virtual Channel Identifier, Start date and time, End date and time, Composite Release Identifier, Location, Product Counter, and file extension.

Schematic explanation of file naming convention for the NISAR RRSD products: NISAR_IL_PT_PROD_CYL_REL_P_RMDE_StartDateTime_EndDateTime_CRID_A_LOC_CTR.ext

Naming schema for the NISAR RRSD product

Schematic explanation of file naming convention for the NISAR RSLC, GSLC, GCOV, and SME2 products: NISAR_IL_PT_PROD_CYL_REL_P_FRM_MODE_POLE_S_StartDateTime_EndDateTime_CRID_A_C_LOC_CTR.EXT

Mission, Beam Mode, Processing Level, Processing Type, Cycle, Relative Orbit, Direction, Frame Number, Mode, Polarization, Source of Data, Product Identifier, Virtual Channel Identifier, Start date and time, End date and time, Composite Release Identifier, Location, Product Counter, and file extension.

Schematic explanation of file naming convention for the NISAR RIFG, RUNW, GUNW, ROFF, GOFF products: NISAR_IL_PT_PROD_CYL_REL_P_FRM_SCY_MODE_PO_RefStartDateTime_RefEndDateTime_ SecStartDateTime_SecEndDateTime_CRID_A_C_LOC_CTR.EXT

Acronyms represent: Mission, Beam Mode, Processing Level, Processing Type, Cycle, Relative Orbit, Direction, Frame Number, Mode, Polarization, Source of Data, Product Identifier, Virtual Channel Identifier, Start date and time, End date and time, Composite Release Identifier, Location, Product Counter, and file extension.

Simulated NISAR Data Products

Simulated NISAR products are generated from Uninhabited Aerial Vehicle SAR (UAVSAR) data to emulate NISAR data characteristics in order to help users test their algorithms and get a sense of the quality of future NISAR products.

The simulated NISAR product names conform to the following naming convention: Sitename_LineID_FlightID_DT_Date_BandSquintPol_XtalkDither_NMode_Version.Ext
This adds the field NMode to the standard UAVSAR PolSAR naming convention.

Field Name	Characters	Field Description
Sitename	6	Abbreviated name for the target site
LineID	5	ID that describes a unique track, where the first 3 digit aircraft heading is followed by a 2 character incremental counter.
FlightID	5	Flight ID describing the unique flight the line is flown in, where the first two digits are the last two digits of the year, and the next three digits are the flight number counted sequentially from the first flight of the year.
DT	3	Data take counter indicating which acquisition during the flight this data was from, counted sequentially from the beginning of the flight and starting from zero.
Date	6	Acquisition date in YYMMDD format indicating the year, month, and day the data was collected in UTC time.
BandSquintPol	4	A single character indicating the frequency band, followed by the steering angle (three digits), sometimes followed by the polarization. If applicable, the polarization may be between 2 characters (first character is the transmit polarization, and second character is the receive polarization) and 4 characters (if the file represents a cross product)
Xtalk	1	Indicates whether cross talk has been calibrated or not: X - no crosstalk calibration, C - cross talk calibration has been applied.
Dither	1	Indicates whether the data has been dithered or not: X - not dithered, G - dithered with gaps, D - dithered with no gaps.
NMode	4	NISAR mode, where a 3-digit mode number associated a specific center frequency, bandwidth, and polarization, is followed by 1-digit character indicating the frequency (A or B).
Version	2	UAVSAR product version number. Increments with new product release of the same acquisition.
Ext	2-5	File extension

NISAR data will be fully and openly available to global data users in keeping with NASA's open data policies.

Instruments Aboard NISAR

Instrument Name	Operational Date(s)	Spectral Resolution	Type of Instrument
NISAR L-band Synthetic Aperture Radar (L-SAR)			Imaging Radar
NISAR S-band Synthetic Aperture Radar (S-SAR)			Imaging Radar

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NISAR

Type

Data Center

Launch