QA4ECV_L2_HCHO
Variables
The table below lists the variables that are present in the HARP product that results from an ingestion of QA4ECV_L2_HCHO data.
| field name | type | dimensions | unit | description |
|---|---|---|---|---|
| scan_subindex | int16 | {time} | pixel index (0-based) within the scanline | |
| datetime | double | {time} | [seconds since 1995-01-01] | start time 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) |
| solar_zenith_angle | float | {time} | [degree] | zenith angle of the Sun at the ground pixel location (WGS84); angle measured away from the vertical |
| relative_azimuth_angle | float | {time} | [degree] | relative azimuth angle 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 |
| surface_altitude | float | {time} | [m] | surface altitude |
| surface_pressure | float | {time} | [hPa] | surface pressure |
| pressure_bounds | double | {time, vertical, 2} | [Pa] | pressure boundaries for each layer |
| cloud_fraction | float | {time} | [] | cloud fraction |
| cloud_fraction_uncertainty | float | {time} | [] | effective cloud fraction uncertainty |
| cloud_pressure | float | {time} | [hPa] | cloud optical centroid pressure from the cloud product |
| cloud_pressure_uncertainty | float | {time} | [hPa] | cloud optical centroid pressure from the cloud product |
| snow_ice_type | int8 | {time} | surface snow/ice type; enumeration values: snow_free_land (0), sea_ice (1), permanent_ice (2), snow (3), ocean (4) | |
| sea_ice_fraction | float | {time} | [] | sea-ice concentration (as a fraction) |
| tropospheric_HCHO_column_number_density | float | {time} | [molec/cm^2] | tropospheric vertical column of HCHO |
| tropospheric_HCHO_column_number_density_uncertainty_random | float | {time} | [molec/cm^2] | uncertainty of the tropospheric vertical column of HCHO due to random effects |
| tropospheric_HCHO_column_number_density_uncertainty_systematic | float | {time} | [molec/cm^2] | uncertainty of the tropospheric vertical column of HCHO due to systematic effects |
| tropospheric_HCHO_column_number_density_amf | float | {time} | [] | tropospheric air mass factor |
| HCHO_column_number_density_avk | float | {time, vertical} | [] | averaging kernel for the total column number density of tropospheric HCHO |
| HCHO_volume_mixing_ratio_dry_air_apriori | float | {time, vertical} | [ppv] | apriori profile for the volume mixing ratio of tropospheric HCHO |
| surface_albedo | float | {time} | [] | surface albedo in the HCHO fitting window |
| validity | int32 | {time} | processing quality flag | |
| index | int32 | {time} | zero-based index of the sample within the source product |
Ingestion options
The table below lists the available ingestion options for QA4ECV_L2_HCHO products.
| option name | legal values | description |
|---|---|---|
| cloud_fraction | radiance | whether to ingest the cloud fraction (default) or the radiance cloud fraction (cloud_fraction=radiance) |
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 | path | /PRODUCT/time, /PRODUCT/delta_time[] |
| description | time converted from milliseconds since a reference time (with the reference time being 1995-01-01) to seconds since 1995-01-01; the time associated with a scanline is repeated for each pixel in the scanline | |
| 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[] |
| solar_zenith_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/solar_zenith_angle[] |
| relative_azimuth_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/relative_azimuth_angle[] |
| sensor_zenith_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/viewing_zenith_angle[] |
| surface_altitude | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_altitude[] |
| surface_pressure | path | /PRODUCT/tm5_surface_pressure[] |
| pressure_bounds | path | /PRODUCT/tm5_pressure_level_a[], /PRODUCT/tm5_pressure_level_b[], /PRODUCT/tm5_surface_pressure[] |
| description | pressure in Pa at level k is derived from surface pressure in hPa as: tm5_pressure_level_a[k] + tm5_pressure_level_b[k] * tm5_surface_pressure[] * 100.0; the TOA pressure is clamped to 1e-3 Pa | |
| cloud_fraction | condition | cloud_fraction unset |
| path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_fraction[] | |
| condition | cloud_fraction=radiance | |
| path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/cloud_radiance_fraction_hcho[] | |
| cloud_fraction_uncertainty | available | optional |
| condition | cloud_fraction unset | |
| path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_fraction_uncertainty[] | |
| cloud_pressure | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_pressure[] |
| cloud_pressure_uncertainty | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_pressure_uncertainty[] |
| snow_ice_type | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/snow_ice_flag[] |
| description | 0: snow_free_land (0), 1-100: sea_ice (1), 101: permanent_ice (2), 103: snow (3), 255: ocean (4), other values map to -1 | |
| sea_ice_fraction | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/snow_ice_flag[] |
| description | if 1 <= snow_ice_flag <= 100 then snow_ice_flag/100.0 else 0.0 | |
| tropospheric_HCHO_column_number_density | path | /PRODUCT/tropospheric_hcho_vertical_column[] |
| tropospheric_HCHO_column_number_density_uncertainty_random | path | /PRODUCT/tropospheric_hcho_vertical_column_uncertainty_random[] |
| tropospheric_HCHO_column_number_density_uncertainty_systematic | path | /PRODUCT/tropospheric_hcho_vertical_column_uncertainty_systematic[] |
| tropospheric_HCHO_column_number_density_amf | path | /PRODUCT/amf_trop[] |
| HCHO_column_number_density_avk | path | /PRODUCT/averaging_kernel[] |
| HCHO_volume_mixing_ratio_dry_air_apriori | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/hcho_profile_apriori[] |
| surface_albedo | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_albedo_hcho[] |
| validity | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/processing_quality_flags[] |