SNAP Data Processors - OLCI O2A Harmonisation Processor Description |

### Processor Description

#### I/O Parameters Tab

##### Source Product Group

OLCI L1b product: Used to select the OLCI L1b source product. The source product can also be a 'compatible' OLCI L1b product, i.e. being collocated with a DEM product in a preprocessing step to add an alternative altitude band. However, in any case, all OLCI L1b source bands must be included. Use the ... button to open a data product currently not opened in the application.

##### Target Product Group

Name: Used to specify the name of the target product.

Save to: Used to specify whether the target product should be saved to the file system. The combo box presents a list of file formats.

Open in SNAP: Used to specify whether the target product should be opened in the application. When the target product is not saved, it is opened automatically.

### The Processing Parameters

Name of alternative altitude band:
The name of an alternative altitude band in the source product. If no name is specified or no band with the given name exists in the source product, this parameter has no effect. There is no default alternative altitude band name.

Only process OLCI band 13 (761.25nm):
If selected, only OLCI band 13 will be processed and its related outputs are written to the target product. Otherwise bands 13-15 will be processed. The default setting is 'true'. This is sufficient for many applications such as cloud screening and significantly saves processing time.

Write harmonised radiances:
If set, the harmonised radiances (recomputed using the retrieved effective transmittances) are written to target product. The default setting value is 'true'.

### The Processor Output

The processor provides for the OLCI O2A bands 13-15 (or optionally just for band 13) the following outputs:

transDesmiled_n:
The desmiled transmission for band n.

trans_n:
The desmiled and rectified transmission for band n.

press_n:
The pressure for band n for a given rectified transmission, which would be measured in given band without scattering. Useful for a first object height estimation for bright targets.

surface_n:
The rectified transmission for band n, which would be measured without scattering ('surface transmission'). Useful only for comparison purposes.

radiance_n:
The harmonised radiance (recomputed using the retrieved effective transmittance) for band n.