NDWI
サマリー
Calculates the Normalized Difference Water Index (NDWI) from a multiband raster object and returns a raster object with the index values.
ディスカッション
The Normalized Difference Water Index (NDWI) method is an index for delineating and monitoring content changes in surface water. It is computed with the NIR and green bands.
\(NDWI \space = \space (Green \space - \space NIR) \space / \space (Green \space + \space NIR)\)
For information about other multiband raster indexes, see the Band Arithmetic raster function.
The referenced raster dataset for the raster object is temporary. To make it permanent, you can call the raster object's save method.
構文
NDWI(raster, {nir_band_id}, {green_band_id})
| パラメーター | 説明 | データ タイプ |
|---|---|---|
|
raster |
The input raster. |
Raster |
|
nir_band_id |
The band ID of the near-infrared band. The ID index uses one-based indexing. The default value is 5. |
Integer |
|
green_band_id |
The band ID of the green band. The ID index uses one-based indexing. The default value is 3. |
Integer |
戻り値
| データ タイプ | 説明 |
|---|---|
|
Raster |
The output raster object with the NDWI index values. |
コードのサンプル
Calculates the Normalized Difference Water Index for a Sentinel-2 image.
import arcpy
NDWI_raster = arcpy.ia.NDWI("Sentinel2.tif", 8, 3)