Copy diapotb wiki into pydiabotb wiki authored by Valentin Genin's avatar Valentin Genin
# SARCorrectionGrid
Computes SAR correction grid.
## Description
This application creates a deformation grid by correcting the DEM grid with correlation grid.
The output grid is a VectorImage composed of two values : shift in range and shift in azimut. The inputs of this application are also vector image with three components. This application can directly take the projectd DEM.
## Parameters
**Input DEM grid (Vector Image)** `-indemgrid image` *Mandatory* <br />
Input DEM Grid Vector Image (Shift_ran, Shift_azi, NbDEMPts for contribution).
**Input Correlation grid (Vector Image)** `-incorgrid image` *Mandatory* <br />
Input orrelation Grid Vector Image (Shift_ran, Shift_azi, Correlation_rate).
**Output Correction grid (Vector Image)** `-out image [dtype]` *Mandatory* <br />
Output Correction Grid Vector Image (Shift_ran, Shift_azi).
**Threshold for correlation rate** `-threshold float` *Default value: 0.3* <br />
Threshold for correlation rate.
**Maximum difference between input grid values and mean values** `-gap float` *Default value: 0.7* <br />
Maximum difference between input grid values and mean values.
**Give an advantage to DEM or Correlation Grid** `-advantage string` <br />
Give an advantage to DEM or Correlation Grid.
**Available RAM (MB)** `-ram int` *Default value: 256* <br />
Available memory for processing (in MB).
## Examples
From the command-line:
```
otbcli_SARCorrectionGrid -indemgrid ./demGrid.tiff -incorgrid ./corGridL.tiff -out correctionGrid.tif
```
From Python:
```
import otbApplication
app = otbApplication.Registry.CreateApplication("SARCorrectionGrid")
app.SetParameterString("indemgrid", "./demGrid.tiff")
app.SetParameterString("incorgrid", "./corGridL.tiff")
app.SetParameterString("out", "correctionGrid.tif")
app.ExecuteAndWriteOutput()
```
## Limitations
Only Sentinel 1 (IW and StripMap mode) and Cosmo products are supported for now.