# GOME2_L1_sun_reference

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of `GOME2_L1_sun_reference` data.

field name | type | dimensions | unit | description
--- | --- | --- | --- | ---
datetime_start | double | {time} | [seconds since 2000-01-01] | start UTC date/time of Sun calibration mode measurement
datetime_stop | double | {time} | [seconds since 2000-01-01] | end UTC date/time of Sun calibration mode measurement
orbit_index | int32 |  |  | absolute orbit number
wavelength_photon_irradiance | double | {time, spectral} | [count/s/cm2/nm] | solar mean reference spectrum
wavelength | double | {time, spectral} | [nm] | nominal wavelength assignment for each of the detector pixels
index | int32 | {time} |  | zero-based index of the sample within the source product

## Ingestion options

The table below lists the available ingestion options for `GOME2_L1` products.

option name | legal values | description
--- | --- | ---
band | band-1a, band-1b, band-2a, band-2b, band-3, band-4 | only include data from the specified band (‘band-1a’, ‘band-1b’, ‘band-2a’, ‘band-2b’, ‘band-3’, ‘band-4’); by default data from all bands is retrieved
data | transmission, sun, moon, sun_reference | retrieve the measured radiances (default), the transmission spectra (data=transmission), the sun measurement spectra (data=sun), the moon measurement spectra (data=moon) or the sun reference spectrum (data=sun_reference

This definition is only applicable when: data=sun_reference

## Mapping description

GOME2 Level 1b sun reference data

The table below details where and how each variable was retrieved from the input product.

field name | mapping description
--- | ---
datetime_start | path | /VIADR_SMR[]/START_UTC_SUN
datetime_stop | path | /VIADR_SMR[]/END_UTC_SUN
orbit_index | path | /MPHR/ORBIT_START
wavelength_photon_irradiance | path | /VIADR_SMR[]/SMR[]
wavelength | path | /VIADR_SDR[]/LAMBDA_SMR[,]