Read Operator |

# Read Operator Description

## Overview

Name: | `Read`
Full name: | `org.esa.snap.core.gpf.common.ReadOp`
Purpose: | Reads a data product from a given file location.
Version: | 1.2

## Description

Reads the specified file as product. This operator may serve as a source node in processing graphs, especially if multiple data products need to be read in.

Here is a sample of how the `Read` operator can be integrated as a node within a processing graph:

        <node id="readNode">
            <operator>Read</operator>
            <parameters>
                <file>/eodata/SST.nc</file>
                <formatName>GeoTIFF</formatName>
            </parameters>
        </node>

## Sources

This operator does not have any sources.

## Parameters

Name | Data Type | Default | Description | Constraints
--- | --- | --- | --- | ---
`file` | `File` | `` | The file from which the data product is read. | not null; non empty
`formatName` | `String` | `` | An (optional) format name. | non empty
`sourceBands` | `String[]` | `` | The list of source bands. |
`sourceMasks` | `String[]` | `` | The list of source masks. |
`pixelRegion` | `Rectangle` | `` | The subset region in pixel coordinates. Use the following format: {x>,{y>,{width>,{height> If not given, the entire scene is used. The 'geoRegion' and 'polygonRegion' parameters has precedence over this parameter. |
`geometryRegion` | `Geometry` | `` | The subset region in geographical coordinates using WKT-format, e.g. POLYGON(({lon1} {lat1}, {lon2} {lat2}, ..., {lon1} {lat1})) (make sure to quote the option due to spaces in {geometry}). If not given, the entire scene is used. |
`polygonRegion` | `Geometry` | `` | The subset region in pixel coordinates using WKT-format, e.g. POLYGON(({x1} {y1}, {x2} {y2}, ..., {x1} {y1})) (make sure to quote the option due to spaces in {geometry}). If not given, the entire scene is used. |
`vectorFile` | `File` | `` | The vector file from which the polygon is read. | Supported vector file formats: SHAPEFILE (*.shp) KML (*.kml) KMZ (*.kmz) GEOJSON (*.json) WKT (*.wkt) TXT (*.txt) PLACEMARK (*.placemark) PNX (*.pnx)
`useAdvancedOptions` | `boolean` | `false` | Whether to use advanced options for reading of the source product. |
`copyMetadata` | `boolean` | `true` | Whether to copy the metadata of the source product. |