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How do you calculate NDVI in Earth Engine?
Calculate NDVI from the Sentinel-2 imagery NDVI is calculated as the normalized difference between the near-infrared band and the red band, which correspond to the 8th and 4th band in the Sentinel-2 imagery.
How does Google Earth Engine calculate raster area?
We can calculate the area of the image by counting the total number of unmasked pixels in that image. Then, multiply the total number of unmasked pixels by the scale factor to get the area in square meters.
How do you find out the area of a polygon?
The area of a regular polygon can be found using the formula, Area = (number of sides × length of one side × apothem)/2.
How is the NDVI calculated in Earth Engine?
NDVI uses this to create a single value roughly reflecting the photosynthetic activity occurring at a pixel. The calculation is (NIR – red) / (NIR + red). This results in a number between 1 and -1, where pixels with high photosynthetic activity have a high NDVI. This is one way to compute NDVI in Earth Engine:
How to calculate the NDVI of a pixel?
NDVI uses this to create a single value roughly reflecting the photosynthetic activity occurring at a pixel. The calculation is (NIR – red) / (NIR + red). This results in a number between 1 and -1, where pixels with high photosynthetic activity have a high NDVI. This is one way to compute NDVI in Earth Engine:
How to calculate the area of an image in Google Earth?
If the image pixels contains values 0 or 1 – we can multiply this pixel area image with our image and calculate the total area using reduceRegion () function. In this example, we extract the pixels for the class Urban Areas (class 13) and see how we can calculate the total built-up area in the state.
How to calculate the normalized difference vegetation index?
This results in a number between 1 and -1, where pixels with high photosynthetic activity have a high NDVI. This is one way to compute NDVI in Earth Engine: // Compute the Normalized Difference Vegetation Index (NDVI). // Display the result.