# ECA_AC__TC__2B

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of `ECA_AC__TC__2B` data.

field name | type | dimensions | unit | description
--- | --- | --- | --- | ---
datetime | double | {time} | [seconds since 2000-01-01] | UTC time
latitude | double | {time} | [degree_north] | Geodetic latitude
longitude | double | {time} | [degree_east] | Geodetic longitude
orbit_index | int32 |  |  | absolute orbit number
altitude | float | {time, vertical} | [m] | joint standard grid height
surface_altitude | float | {time} | [m] | surface altitude
scene_type | int8 | {time, vertical} |  | synergetic target classification
index | int32 | {time} |  | zero-based index of the sample within the source product

## Ingestion options

The table below lists the available ingestion options for `ECA_AC__TC__2B` products.

option name | legal values | description
--- | --- | ---
resolution | medium, low | classification resolution: normal (default), medium (resolution=medium), or low (resolution=low)

## Mapping description

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

field name | mapping description
--- | ---
datetime | path | /ScienceData/time
latitude | path | /ScienceData/latitude
longitude | path | /ScienceData/longitude
orbit_index | path | /HeaderData/VariableProductHeader/MainProductHeader/orbitNumber
altitude | path | /ScienceData/height, /ScienceData/geoid_offset
description | the vertical grid is inverted to make it ascending; altitude[i,j] = height[i,j] - geoid_offset[i]
surface_altitude | path | /ScienceData/elevation, /ScienceData/geoid_offset
description | altitude = elevation - geoid_offset
scene_type | condition | resolution unset
path | /ScienceData/synergetic_target_classification
description | the vertical grid is inverted to make it ascending
condition | resolution=medium
path | /ScienceData/synergetic_target_classification_medium_resolution
description | the vertical grid is inverted to make it ascending
condition | resolution=low
path | /ScienceData/synergetic_target_classification_low_resolution
description | the vertical grid is inverted to make it ascending