S4-L2-OTR

Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of S4-L2-OTR data.

field name

type

dimensions

unit

description

scan_subindex

int16

{time}

pixel index (0-based) within the scanline

cycle_index

int32

repeat cycle number within the day

datetime

double

{time}

[seconds since 2000-01-01]

time of the measurement

datetime_length

double

[s]

measurement duration

latitude

float

{time}

[degree_north]

pixel center latitude

longitude

float

{time}

[degree_east]

pixel center longitude

latitude_bounds

float

{time, 4}

[degree_north]

latitudes of pixel boundary

longitude_bounds

float

{time, 4}

[degree_east]

longitudes of pixel boundary

validity

int8

{time}

continuous quality descriptor, varying between 0 (no data) and 100 (full quality data)

solar_zenith_angle

float

{time}

[degree]

zenith angle of the Sun at the ground pixel location; angle measured away from the vertical

solar_azimuth_angle

float

{time}

[degree]

azimuth angle of the Sun at the ground pixel location; angle measured clockwise from North

viewing_zenith_angle

float

{time}

[degree]

zenith angle of the satellite at the ground pixel location; angle measured away from the vertical

viewing_azimuth_angle

float

{time}

[degree]

azimuth angle of the satellite at the ground pixel location; angle measured clockwise from North

surface_altitude

float

{time}

[m]

surface altitude

surface_altitude_uncertainty

float

{time}

[m]

standard error of surface altitude

surface_pressure

float

{time}

[Pa]

surface pressure

surface_type

int32

{time}

surface type classification

snow_ice_type

int8

{time}

surface snow/ice type; enumeration values: snow_free_land (0), snow_ice (1)

cloud_fraction

float

{time}

[]

cloud fraction

cloud_top_pressure

float

{time}

[Pa]

cloud top pressure

surface_albedo

float

{time}

[]

assumed white sky surface albedo at 342 nm

pressure_bounds

float

{vertical, 2}

[Pa]

pressure boundaries

O3_volume_mixing_ratio

float

{time, vertical}

[ppmv]

sub-column average volume mixing ratio of ozone

O3_volume_mixing_ratio_uncertainty

float

{time, vertical}

[ppmv]

standard error of the sub-column average volume mixing ratio of ozone

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 ground_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 pixels per scanline

cycle_index

path

/@repeat_cycle_in_day[0]

description

parsed from the string attribute repeat_cycle_in_day

datetime

path

/@time_reference_days_since_1950, /PRODUCT/delta_time[]

description

time reference converted from days since 1950-01-01 to seconds since 2000-01-01 (using 86400 seconds per day) and delta_time added

datetime_length

path

/PRODUCT/delta_time[]

description

delta_time[num_ground_pixels] - delta_time[0]

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[]

validity

path

/PRODUCT/qa_value

solar_zenith_angle

path

/PRODUCT/SUPPORT_DATA/GEOLOCATIONS/solar_zenith_angle[]

solar_azimuth_angle

path

/PRODUCT/SUPPORT_DATA/GEOLOCATIONS/solar_azimuth_angle[]

viewing_zenith_angle

path

/PRODUCT/SUPPORT_DATA/GEOLOCATIONS/viewing_zenith_angle[]

viewing_azimuth_angle

path

/PRODUCT/SUPPORT_DATA/GEOLOCATIONS/viewing_azimuth_angle[]

surface_altitude

path

/PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_altitude[]

surface_altitude_uncertainty

path

/PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_altitude_precision[]

surface_pressure

path

/PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_pressure[]

surface_type

path

/PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_classification[]

snow_ice_type

path

/PRODUCT/SUPPORT_DATA/INPUT_DATA/snow_ice_flag[]

description

0: snow_free_land, 1: snow_ice

cloud_fraction

path

/PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_fraction[]

cloud_top_pressure

path

/PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_top_pressure[]

surface_albedo

path

/PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_albedo[]

pressure_bounds

path

/PRODUCT/subcolumn_bounds[]

O3_volume_mixing_ratio

path

/PRODUCT/ozone_subcolumn[]

O3_volume_mixing_ratio_uncertainty

path

/PRODUCT/ozone_subcolumn_precision[]