IASI_L1
Variables
The table below lists the variables that are present in the HARP product that results from an ingestion of IASI_L1 data.
| field name | type | dimensions | unit | description |
|---|---|---|---|---|
| datetime | double | {time} | [seconds since 2000-01-01] | time of the measurement |
| orbit_index | int32 | absolute orbit number | ||
| latitude | double | {time} | [degree_north] | center latitude of the measurement |
| longitude | double | {time} | [degree_east] | center longitude of the measurement |
| wavenumber_radiance | float | {time, spectral} | [W/m^2.sr.m^-1] | measured radiances |
| wavenumber | float | {time, spectral} | [m^-1] | nominal wavelength assignment for each of the detector pixels |
| scan_subindex | int8 | {time} | relative index (0-119) of this measurement within an MDR | |
| index | int32 | {time} | zero-based index of the sample within the source product |
Mapping description
IASI Level 1 products contain a number of scanlines, each scanline contains 30 scans, each scan contains 4 spectra and each spectrum contains 8700 measurements
The table below details where and how each variable was retrieved from the input product.
| field name | mapping description | |
|---|---|---|
| datetime | path | /MDR[]/MDR/RECORD_HEADER/RECORD_START_TIME |
| description | ||
| orbit_index | path | /MPHR/ORBIT_START |
| latitude | path | /MDR[]/MDR/GGeoSondLoc[,,1] |
| longitude | path | /MDR[]/MDR/GGeoSondLoc[,,0] |
| wavenumber_radiance | path | /MDR[]/MDR/GS1cSpect[], /MDR[]/MDR/IDefNsfirst1b, /GIADR_ScaleFactors/IDefScaleSondNbScale, /GIADR_ScaleFactors/IDefScaleSondScaleFactor[], /GIADR_ScaleFactors/IdefScaleSondNsfirst[], /GIADR_ScaleFactors/IDefScaleSondNslast[] |
| description | spectral data is scaled using the information in GIADR_ScaleFactors:for numScale = 0 to (IDefScaleSondNbScale - 1) do { SF = IDefScaleSondScaleFactor[numScale]; for chanNb = IdefScaleSondNsfirst[numScale] to IDefScaleSondNslast[numScale] do { w = chanNb - IDefNsfirst1b + 1; pixel_readout[w] = GS1cSpect[..,..,w] * 10^(-SF) } } |
|
| wavenumber | path | /MDR[]/MDR/IDefSpectDWn1b, /MDR[]/MDR/IDefNsfirst1b, /MDR[]/MDR/IDefNslast1b |
| description | wavenumber[i] = IDefSpectDWn1b * (i + IDefNsfirst1b - 1). | |