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
solar_azimuth_angle	double	{time}	[degree]	solar azimuth angle at the surface
solar_zenith_angle	double	{time}	[degree]	solar zenith angle at the surface
sensor_azimuth_angle	double	{time}	[degree]	sensor azimuth angle
sensor_zenith_angle	double	{time}	[degree]	sensor zenith angle
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]
solar_azimuth_angle	path	/MDR[]/MDR/GGeoSondAnglesSUN[,,1]
solar_zenith_angle	path	/MDR[]/MDR/GGeoSondAnglesSUN[,,0]
sensor_azimuth_angle	path	/MDR[]/MDR/GGeoSondAnglesMETOP[,,1]
sensor_zenith_angle	path	/MDR[]/MDR/GGeoSondAnglesMETOP[,,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).