# GEOMS-TE-FTIR-001-C2H4

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of `GEOMS-TE-FTIR-001-C2H4` data.

field name | type | dimensions | unit | description
--- | --- | --- | --- | ---
sensor_name | string |  |  | name of the sensor
location_name | string |  |  | name of the site at which the sensor is located
measurement_mode | string |  |  | ‘solar’ or ‘lunar’ measurement
sensor_latitude | double |  | [degree_north] | latitude of the sensor
sensor_longitude | double |  | [degree_east] | longitude of the sensor
sensor_altitude | double |  | [km] | altitude of the sensor
datetime | double | {time} | [days since 2000-01-01] | time of the measurement
datetime_length | double | {time} | [s] | duration of the measurement
C2H4_column_number_density | double | {time} | [molec/m2] | total C2H4 vertical column
C2H4_column_number_density_apriori | double | {time} | [molec/m2] | a priori total C2H4 vertical column
C2H4_column_number_density_avk | double | {time, vertical} | [] | averaging kernel for the total C2H4 vertical column
C2H4_column_number_density_uncertainty_random | double | {time} | [molec/m2] | random uncertainty of the total C2H4 vertical column
C2H4_column_number_density_uncertainty_systematic | double | {time} | [molec/m2] | systematic uncertainty of the total C2H4 vertical column
H2O_column_number_density | double | {time} | [molec/m2] | total H2O vertical column
C2H4_volume_mixing_ratio_dry_air | double | {time, vertical} | [ppmv] | C2H4 volume mixing ratio
C2H4_volume_mixing_ratio_dry_air_apriori | double | {time, vertical} | [ppmv] | a priori C2H4 volume mixing ratio
C2H4_volume_mixing_ratio_dry_air_avk | double | {time, vertical, vertical} | [] | averaging kernel for the C2H4 volume mixing ratio
C2H4_volume_mixing_ratio_dry_air_covariance | double | {time, vertical, vertical} | [(ppmv)2] | covariance of the C2H4 volume mixing ratio
C2H4_volume_mixing_ratio_dry_air_uncertainty_random | double | {time, vertical} | [ppmv] | random uncertainty of the C2H4 volume mixing ratio
C2H4_volume_mixing_ratio_dry_air_uncertainty_systematic | double | {time, vertical} | [ppmv] | systematic uncertainty of the C2H4 volume mixing ratio
H2O_volume_mixing_ratio_dry_air | double | {time, vertical} | [ppmv] | H2O volume mixing ratio
altitude | double | {time, vertical} | [km] | retrieval effective altitude
altitude_bounds | double | {time, vertical, 2} | [km] | lower and upper boundaries of the height layers
pressure | double | {time, vertical} | [hPa] | independent pressure profile
temperature | double | {time, vertical} | [K] | independent temperature profile
surface_pressure | double | {time} | [hPa] | independent surface pressure
surface_temperature | double | {time} | [K] | independent surface temperature
solar_azimuth_angle | double | {time} | [degree] | solar azimuth angle
solar_zenith_angle | double | {time} | [degree] | solar zenith angle
index | int32 | {time} |  | zero-based index of the sample within the source product

## Mapping description

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

field name | mapping description
--- | ---
sensor_name | path | /@DATA.SOURCE
location_name | path | /@DATA.LOCATION
measurement_mode | condition | determined from ‘variable mode’ part of variable names
sensor_latitude | path | /LATITUDE.INSTRUMENT
sensor_longitude | path | /LONGITUDE.INSTRUMENT
sensor_altitude | path | /ALTITUDE.INSTRUMENT
datetime | path | /DATETIME
datetime_length | available | optional
path | /INTEGRATION.TIME
C2H4_column_number_density | condition | solar measurement
path | /C2H4.COLUMN_ABSORPTION.SOLAR
description | unit is converted to molec/m2
condition | lunar measurement
path | /C2H4.COLUMN_ABSORPTION.LUNAR
description | unit is converted to molec/m2
C2H4_column_number_density_apriori | condition | solar measurement
path | /C2H4.COLUMN_ABSORPTION.SOLAR_APRIORI
description | unit is converted to molec/m2
condition | lunar measurement
path | /C2H4.COLUMN_ABSORPTION.LUNAR_APRIORI
description | unit is converted to molec/m2
C2H4_column_number_density_avk | condition | solar measurement
path | /C2H4.COLUMN_ABSORPTION.SOLAR_AVK
description | the vertical axis is re-ordered from surface to top-of-atmosphere
condition | lunar measurement
path | /C2H4.COLUMN_ABSORPTION.LUNAR_AVK
description | the vertical axis is re-ordered from surface to top-of-atmosphere
C2H4_column_number_density_uncertainty_random | condition | solar measurement
path | /C2H4.COLUMN_ABSORPTION.SOLAR_UNCERTAINTY.RANDOM
description | unit is converted to molec/m2
condition | lunar measurement
path | /C2H4.COLUMN_ABSORPTION.LUNAR_UNCERTAINTY.RANDOM
description | unit is converted to molec/m2
C2H4_column_number_density_uncertainty_systematic | condition | solar measurement
path | /C2H4.COLUMN_ABSORPTION.SOLAR_UNCERTAINTY.SYSTEMATIC
description | unit is converted to molec/m2
condition | lunar measurement
path | /C2H4.COLUMN_ABSORPTION.LUNAR_UNCERTAINTY.SYSTEMATIC
description | unit is converted to molec/m2
H2O_column_number_density | condition | solar measurement
path | /H2O.COLUMN_ABSORPTION.SOLAR
description | unit is converted to molec/m2
condition | lunar measurement
path | /H2O.COLUMN_ABSORPTION.LUNAR
description | unit is converted to molec/m2
C2H4_volume_mixing_ratio_dry_air | available | optional
condition | solar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.SOLAR
description | unit is converted to ppmv; the vertical axis is re-ordered from surface to top-of-atmosphere
condition | lunar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.LUNAR
description | unit is converted to ppmv; the vertical axis is re-ordered from surface to top-of-atmosphere
C2H4_volume_mixing_ratio_dry_air_apriori | available | optional
condition | solar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.SOLAR_APRIORI
description | unit is converted to ppmv; the vertical axis is re-ordered from surface to top-of-atmosphere
condition | lunar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.LUNAR_APRIORI
description | unit is converted to ppmv; the vertical axis is re-ordered from surface to top-of-atmosphere
C2H4_volume_mixing_ratio_dry_air_avk | available | optional
condition | solar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.SOLAR_AVK
description | the vertical axis is re-ordered from surface to top-of-atmosphere
condition | lunar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.LUNAR_AVK
description | the vertical axis is re-ordered from surface to top-of-atmosphere
C2H4_volume_mixing_ratio_dry_air_covariance | available | optional
condition | solar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.SOLAR_UNCERTAINTY.RANDOM
description | unit is converted to (ppmv)2; the vertical axis is re-ordered from surface to top-of-atmosphere
condition | lunar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.LUNAR_UNCERTAINTY.RANDOM
description | unit is converted to (ppmv)2; the vertical axis is re-ordered from surface to top-of-atmosphere
C2H4_volume_mixing_ratio_dry_air_uncertainty_random | available | optional
condition | solar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.SOLAR_UNCERTAINTY.RANDOM
description | the vertical axis is re-ordered from surface to top-of-atmosphere; the uncertainty is the square root of the trace of the covariance; unit is converted to ppmv
condition | lunar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.LUNAR_UNCERTAINTY.RANDOM
description | the vertical axis is re-ordered from surface to top-of-atmosphere; the uncertainty is the square root of the trace of the covariance; unit is converted to ppmv
C2H4_volume_mixing_ratio_dry_air_uncertainty_systematic | available | optional
condition | solar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.SOLAR_UNCERTAINTY.SYSTEMATIC
description | the vertical axis is re-ordered from surface to top-of-atmosphere; the uncertainty is the square root of the trace of the covariance; unit is converted to ppmv
condition | lunar measurement
path | /C2H4.MIXING.RATIO_ABSORPTION.LUNAR_UNCERTAINTY.SYSTEMATIC
description | the vertical axis is re-ordered from surface to top-of-atmosphere; the uncertainty is the square root of the trace of the covariance; unit is converted to ppmv
H2O_volume_mixing_ratio_dry_air | condition | solar measurement
path | /H2O.MIXING.RATIO_ABSORPTION.SOLAR
description | unit is converted to ppmv; the vertical axis is re-ordered from surface to top-of-atmosphere
condition | lunar measurement
path | /H2O.MIXING.RATIO_ABSORPTION.LUNAR
description | unit is converted to ppmv; the vertical axis is re-ordered from surface to top-of-atmosphere
altitude | path | /ALTITUDE
description | the vertical axis is re-ordered from surface to top-of-atmosphere
altitude_bounds | path | /ALTITUDE.BOUNDS
description | lower and upper boundaries of the height layers
pressure | path | /PRESSURE_INDEPENDENT
description | independent pressure profile
temperature | path | /TEMPERATURE_INDEPENDENT
description | independent temperature profile
surface_pressure | path | /SURFACE.PRESSURE_INDEPENDENT
surface_temperature | path | /SURFACE.TEMPERATURE_INDEPENDENT
solar_azimuth_angle | condition | solar measurement
path | /ANGLE.SOLAR_AZIMUTH
condition | lunar measurement
path | /ANGLE.LUNAR_AZIMUTH
solar_zenith_angle | condition | solar measurement
path | /ANGLE.SOLAR_ZENITH.ASTRONOMICAL
condition | lunar measurement
path | /ANGLE.LUNAR_ZENITH.ASTRONOMICAL