LandWaterMask Operator |

# LandWaterMask Operator Description

## Overview

Name: | `LandWaterMask`
Full name: | `org.esa.snap.watermask.operator.WatermaskOp`
Purpose: | Operator creating a target product with a single band containing a land/water-mask.
Version: | 1.3

## Description

The watermask operator is a GPF-Operator. It takes the geographic bounds of the input product and creates a new product with the same bounds. The output product contains a single band, which is a land/water fraction mask. For each pixel, it contains the fraction of water; a value of 0.0 indicates land, a value of 100.0 indicates water, and every value in between indicates a mixed pixel.
There are two auxiliary data sets on which the watermask can be based. The first, high-res dataset is based on data given by SRTM-shapefiles between 60° north and 58° south, and by the GlobCover world map above 60° north. Below 58° south, this dataset does not contain any data, so the resulting product will contain the fill value for these parts. This high-res dataset will be employed when the resolution parameter is set to 50 or 150.
The second dataset is based on GSHHS data in a resolution of 1 km. It covers the whole earth, and will be employed when the resolution parameter is set to 1000.
Since the base data may exhibit a higher resolution than the input product, a subsampling ≥1 may be specified. This means that mixed pixels may occur.

## Sources

Name | Description
--- | ---
`sourceProduct` | The Product the land/water-mask shall be computed for.

## Parameters

Name | Data Type | Default | Description | Constraints
--- | --- | --- | --- | ---
`resolution` | `int` | `50` | Specifies on which resolution the water mask shall be based. | value set: [50, 150, 1000]
`subSamplingFactorX` | `int` | `1` | Specifies the factor between the resolution of the source product and the watermask in x direction. A value of '1' means no subsampling at all. | not null
`subSamplingFactorY` | `int` | `1` | Specifies the factor between the resolution of the source product and the watermask iny direction. A value of '1' means no subsampling at all. | not null