# S5P_PAL_L2_TCWV

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of `S5P_PAL_L2_TCWV` data.

field name | type | dimensions | unit | description
--- | --- | --- | --- | ---
scan_subindex | int16 | {time} |  | pixel index (0-based) within the scanline
datetime_start | double | {time} | [seconds since 2010-01-01] | start time of the measurement
datetime_length | double |  | [s] | duration of the measurement
orbit_index | int32 |  |  | absolute orbit number
latitude | float | {time} | [degree_north] | latitude of the ground pixel center (WGS84)
longitude | float | {time} | [degree_east] | longitude of the ground pixel center (WGS84)
latitude_bounds | float | {time, 4} | [degree_north] | latitudes of the ground pixel corners (WGS84)
longitude_bounds | float | {time, 4} | [degree_east] | longitudes of the ground pixel corners (WGS84)
sensor_latitude | float | {time} | [degree_north] | latitude of the geodetic sub-satellite point (WGS84)
sensor_longitude | float | {time} | [degree_east] | longitude of the goedetic sub-satellite point (WGS84)
sensor_altitude | float | {time} | [m] | altitude of the satellite with respect to the geodetic sub-satellite point (WGS84)
solar_zenith_angle | float | {time} | [degree] | zenith angle of the Sun at the ground pixel location (WGS84); angle measured away from the vertical
solar_azimuth_angle | float | {time} | [degree] | azimuth angle of the Sun at the ground pixel location (WGS84); angle measured East-of-North
sensor_zenith_angle | float | {time} | [degree] | zenith angle of the satellite at the ground pixel location (WGS84); angle measured away from the vertical
sensor_azimuth_angle | float | {time} | [degree] | azimuth angle of the satellite at the ground pixel location (WGS84); angle measured East-of-North
pressure_bounds | float | {time, vertical, 2} | [Pa] | pressure_bounds
cloud_fraction | float | {time} | [] | Retrieved effective radiometric cloud fraction using the OCRA/ROCINN CRB model
cloud_pressure | float | {time} | [Pa] | Retrieved atmospheric pressure at the level of cloud using the OCRA/ROCINN CRB model
cloud_albedo | float | {time} | [] | cloud albedo
surface_pressure | float | {time} | [Pa] | surface air pressure
surface_albedo | float | {time} | [] | surface albedo
water_vapor_column_density | float | {time} | [kg/m^2] | total vertical column of water vapor
water_vapor_column_density_uncertainty | float | {time} | [kg/m^2] | precision of the total vertical column of water vapor
water_vapor_column_density_validity | int8 | {time} |  | continuous quality descriptor, varying between 0 (no data) and 100 (full quality data)
water_vapor_column_density_amf | float | {time} | [] | water vapor total column air mass factor
water_vapor_column_density_avk | float | {time, vertical} | [] | total column averaging kernel
water_vapor_mass_mixing_ratio_apriori | float | {time, vertical} | [kg/kg] | a-priori mass mixing ratio profile of water vapor
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
--- | ---
scan_subindex | description | the scanline and pixel dimensions are collapsed into a temporal dimension; the index of the pixel within the scanline is computed as the index on the temporal dimension modulo the number of scanlines
datetime_start | path | /PRODUCT/time, /PRODUCT/delta_time[]
description | time converted from milliseconds since a reference time (given as seconds since 2010-01-01) to seconds since 2010-01-01 (using 86400 seconds per day); the time associated with a scanline is repeated for each pixel in the scanline
datetime_length | path | /@time_coverage_resolution
description | the measurement length is parsed assuming the ISO 8601 ‘PT%(interval_seconds)fS’ format
orbit_index | path | /@orbit
latitude | path | /PRODUCT/latitude[]
longitude | path | /PRODUCT/longitude[]
latitude_bounds | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/latitude_bounds[]
longitude_bounds | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/longitude_bounds[]
sensor_latitude | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/satellite_latitude[]
description | the satellite latitude associated with a scanline is repeated for each pixel in the scanline
sensor_longitude | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/satellite_longitude[]
description | the satellite longitude associated with a scanline is repeated for each pixel in the scanline
sensor_altitude | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/satellite_altitude[]
description | the satellite altitude associated with a scanline is repeated for each pixel in the scanline
solar_zenith_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/solar_zenith_angle[]
solar_azimuth_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/solar_azimuth_angle[]
sensor_zenith_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/viewing_zenith_angle[]
sensor_azimuth_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/viewing_azimuth_angle[]
pressure_bounds | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/pressure_constant_a_top[], /PRODUCT/SUPPORT_DATA/INPUT_DATA/pressure_constant_a_bottom[], /PRODUCT/SUPPORT_DATA/INPUT_DATA/pressure_constant_b_top[], /PRODUCT/SUPPORT_DATA/INPUT_DATA/pressure_constant_b_bottom[], /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_pressure[]
description | pressure in Pa at layer k is derived from surface pressure in Pa as: pressure_constant_a_top[k] + pressure_constant_b_top[k] * surface_pressure[] for the top and pressure_constant_a_bottom[k] + pressure_constant_b_bottom[k] * surface_pressure[] for the bottom of the layer
cloud_fraction | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_fraction[]
cloud_pressure | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_pressure[]
cloud_albedo | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_albedo
surface_pressure | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_pressure[]
surface_albedo | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_albedo[]
water_vapor_column_density | path | /PRODUCT/total_column_water_vapor
water_vapor_column_density_uncertainty | path | /PRODUCT/total_column_water_vapor_precision
water_vapor_column_density_validity | path | /PRODUCT/qa_value
water_vapor_column_density_amf | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/air_mass_factor_total[]
water_vapor_column_density_avk | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/averaging_kernel[]
water_vapor_mass_mixing_ratio_apriori | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/water_vapour_profile_apriori[]