Level 1 (L1) Product
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| Version | Date | Update | Release Note |
|---|---|---|---|
| vCa | 2025/1/14 | Start of data provision | |
| vCb | 2025/3/13 | ・A +1.6 dB calibration was applied to the received power based on external calibration results obtained using the Active Radar Calibrator (ARC). ・The value of rayHeaderRangeBinSize was corrected. ・The degradedQualityFlag was corrected. | |
| vCc | 2025/7/9 | The CPR observation mode was changed from 20km to 18km for latitudes between 60°S and 60°N. | |
| vCd | 2025/8/6 | ・The resolution of the noise floor was improved. ・The TxRxStatusFlag was corrected. ・The missingRayNumber was corrected. | |
| vDa | 2025/10/16 | ・The method for calculating binHeight was corrected. ・The selective use of the Doppler reference signal was disabled. ・The number of valid bins in the external calibration mode was fixed. |
| Name | Number of Pixels | Description |
|---|---|---|
| nray | - | Number of ray |
| nbin | 218 (Nominal observation mode) 544 (Contingency observation mode) |
Number of bin |
| Variable Name | Units | Description/Attributes | Dimention | Type |
|---|---|---|---|---|
| Data | ||||
| operationalMode | unitless | Observation Mode 4: Normal Observation 5: Sea-Surface Calibration 6: External Calibration 8: Contingency Observation
|
nray | H5T_STD_U16LE |
| subOperationalMode | unitless | Sub Observation Mode (operationalMode=4) 1: Low 2: Middle 3: High 5: MIX (Low) 6: MIX (Middle) 7: MIX (High) (operationalMode=8) 1: Contingency Obs 2: External Cal 3: Sea-Surface Cal (operationalMode=5,6) other 0
|
nray | H5T_STD_U16LE |
| rangeBinValidNumber | unitless | Number of Valid Range Bin with Observation mode
|
nray | H5T_STD_U16LE |
| rayStatusPrf | Hz | Pulse Repetition Frequency (PRF) at each ray
|
nray | H5T_IEEE_F32LE |
| integrationNumberEcho | unitless | Pulse Integration Number of the Echo for Each Ray
|
nray | H5T_STD_I16LE |
| integrationNumberDoppler | unitless | Integration Number of the Pulse-Pair for Each Ray
|
nray | H5T_STD_I16LE |
| rayHeaderCalVers | unitless | L1b version control file version
|
1 | H5T_STD_U32LE |
| rayHeaderLambda | m | Radar Wave Length (Fixed Value)
|
1 | H5T_IEEE_F64LE |
| radarCoefficient | 1/m3 | Radar Coefficient for Calculation of Reflectivity
|
nray | H5T_IEEE_F32LE |
| pulseWidth | us | Estimated Transmit Pulse Length
|
nray | H5T_IEEE_F32LE |
| transmitPower | W | Transmit Power of Each Ray
|
nray | H5T_IEEE_F32LE |
| transmitPowerAvg | W | Averaged Transmit Power for one Orbital Cycle
|
1 | H5T_IEEE_F32LE |
| pulseShapeWarnFlag | unitless | Quality Flag for Transmit Power Estimation
|
nray | H5T_STD_U16LE |
| receivedEchoPower | W | Received Echo Power before Subtraction of Noise Power
|
nray, nbin | H5T_IEEE_F32LE |
| noiseFloorPower | W | Received Noise Level
|
nray | H5T_IEEE_F32LE |
| radarReflectivityFactor | mm6/m3 | Radar Reflectivity Factor without Attenuation Correction
|
nray, nbin | H5T_IEEE_F32LE |
| dopplerVelocity | m/s | Radial Doppler Velocity (Corrected with satellite velocity contamination and Doppler reference signal)
|
nray, nbin | H5T_IEEE_F32LE |
| spectrumWidth | m/s | Doppler Spectral Width
|
nray, nbin | H5T_IEEE_F32LE |
| covarianceCoeff | unitless | Covariance Coefficient of Pulse-Pair with Doppler Reference Correction (Real Part and Imaginary Part)
|
nray, nbin | H5T_IEEE_F32LE |
| binStatusFlag | unitless | Quality Flag for Received Echo Power and Doppler measurement at each range bin (Echo level at each range bin shows saturation or low level of Log Detector and IQ detector)
|
nray, nbin | H5T_STD_U8LE |
| txRxStatusFlag | unitless | Quality Flag for Transmitter and Receiver Performance (Transmitter off; Warm-up stage of transmitter; Abnormal Receiver Gain)
|
nray | H5T_STD_U16LE |
| dopplerStatusFlag | unitless | Quality Flag for Doppler measurement (Corrections of IQ detector; Doppler Reference signal; Satellite velocity contamination may have larger error)
|
nray | H5T_STD_U16LE |
| sigmaZero | dB | Normalised Radar Cross Section on Surface
|
nray | H5T_IEEE_F32LE |
| surfaceBinNumber | unitless | Estimated Surface Bin Number (Integer)
|
nray | H5T_STD_I16LE |
| surfaceBinFraction | unitless | Fraction of Surface Bin Number (-0.5 to +0.5)
|
nray | H5T_IEEE_F32LE |
| surfaceEstimationFlag | unitless | Quality Flag for Surface Bin Estimation
|
nray | H5T_STD_U16LE |
| rayStatusFlag | unitless | Quality Flag for onboard Signal Processing and ground L1 processing
|
nray | H5T_STD_U32LE |
| rayQualityFlag | unitless | Quality information determined by combinations of the other quality flags in ray (rayStatusFlag, surfaceEstimationFlag, pulseShapeWarnFlag, dopplerStatusFlag, txRxStatusFlag). When all quality flags in ray show no errors and no warnings, this flag indicates 0
|
nray | H5T_STD_U8LE |
| dopplerVelocityAtSurfaceBin | m/s | Doppler velocity at the surface bin
|
nray | H5T_IEEE_F32LE |
| satelliteVelocityContaminationInLOS | m/s | Satellite velocity in line-of-sight (LOS)
|
nray | H5T_IEEE_F32LE |
| Geo | ||||
| profileTime | seconds since 2000-1-1 00:00:00.0 | Representative Time of each ray Sequential seconds counted from 1/1/2000
|
nray | H5T_IEEE_F64LE |
| timeFlag | unitless | Synchronization Flag between CPR time and Satellite time (1: Synchronized 0: Unsynchronized)
|
nray | H5T_STD_U16LE |
| latitude | degree_north | Latitude (degree) of ray centre position given in geodetic reference frame
|
nray | H5T_IEEE_F64LE |
| longitude | degree_east | Longitude (degree) of ray centre position given in geodetic reference frame
|
nray | H5T_IEEE_F64LE |
| rayHeaderSpatAvg | m | Horizontal Satellite-Track Length for one Ray
|
nray | H5T_IEEE_F32LE |
| rangeToIntercept | m | Range (m) from satellite to the geoid surface at each ray
|
nray | H5T_IEEE_F32LE |
| surfaceElevation | m | Representative surface elevation (m) from the WGS84 surface at each ray
|
nray | H5T_IEEE_F32LE |
| binHeight | m | Representative height (m) from the WGS84 surface corresponding to each bin
|
nray, nbin | H5T_IEEE_F32LE |
| navigationLandWaterFlg | unitless | Land-Water Flag (0:water 1:land 65535:invalid) The land/water mask derived from Globcover is used.
|
nray | H5T_STD_U16LE |
| rangeToFirstBin | m | Distance (m) from satellite to the first sampling bin in L1b data at each ray
|
nray | H5T_IEEE_F32LE |
| rayHeaderRangeBinSize | m | One Sample Bin Range (m) (Fixed value from L1 specific file)
|
1 | H5T_IEEE_F32LE |
| pitchAngle | degree | Rotation angle around rotated -Xs. Note that this angle includes the satellite attitude and the CPR antenna's offset angle determined by CPR attachment error and thermal distortion of the antenna.
|
nray | H5T_IEEE_F32LE |
| rollAngle | degree | Rotation angle around -Ys (satellite orbit frame). Note that this angle includes the satellite attitude and the antenna's offset angle determined by CPR attachment error and thermal distortion of the antenna.
|
nray | H5T_IEEE_F32LE |
| yawAngle | degree | Rotation angle around rotated +Z1s axis. Note that this angle includes the satellite attitude and the antenna's offset angle determined by CPR attachment error.
|
nray | H5T_IEEE_F32LE |
| xPosition | m | X Position of Satellite (m) with Earth Centred Earth Fixed (ECEF) coordinate
|
nray | H5T_IEEE_F64LE |
| yPosition | m | Y Position of Satellite (m) with ECEF coordinate
|
nray | H5T_IEEE_F64LE |
| zPosition | m | Z Position of Satellite (m) with ECEF coordinate
|
nray | H5T_IEEE_F64LE |
| satelliteVelocityX | m/s | X Component of Satellite Velocity (m/s) with ECEF coordinate
|
nray | H5T_IEEE_F64LE |
| satelliteVelocityY | m/s | Y Component of Satellite Velocity (m/s) with ECEF coordinate
|
nray | H5T_IEEE_F64LE |
| satelliteVelocityZ | m/s | Z Component of Satellite Velocity (m/s) with ECEF coordinate
|
nray | H5T_IEEE_F64LE |
| solarElevationAngle | degree | Solar elevation angle
|
nray | H5T_IEEE_F32LE |
| solarAzimuthAngle | degree | Solar azimuth angle
|
nray | H5T_IEEE_F32LE |
| processingFrameNo | unitless | Sequential number of rays in each control cycle
|
nray | H5T_STD_I16LE |
| rangeBinMaxNumber | unitless | Maximum Range Bin Size for this L1B product ( 218 for Normal Observation or 544 for Contingency Observation)
|
1 | H5T_STD_I16LE |
| rayNumber | unitless | Number of Ray within L1B Product (28(Frame start margin ray) + One Frame + 28(Frame stop margin ray))
|
1 | H5T_STD_I16LE |
Please reffer to the "Product Definition Document" for header information.