I want to calculate the mean over an area in Google Earth Engine. I am unable to exactly understand the meaning of scale in the function reduceRegion (https://developers.google.com/earth-engine/apidocs/ee-image-reduceregion) I checked https://developers.google.com/earth-engine/guides/scale but am still not clear. In other examples on stack exchange people have shown examples with landsat and have shown them with scale as 30. As I am trying to understand this, it should be equal to the spatial resolution of the data. And as the landsat data is at 30m spatial resolution, the scale being used is 30?
I am specifically trying to use the data https://developers.google.com/earth-engine/datasets/catalog/MODIS_006_MOD09GA
Is the following code right
region = ee.Geometry.Polygon([ [[74, 14], [87, 14],[87, 28], [74, 28], [74, 14]] ]); collection_ndvi = ee.ImageCollection('MODIS/MYD09GA_006_NDVI').select('NDVI').filterDate(dates,datee ).mean() data = collection_ndvi.reduceRegion(ee.Reducer.mean(), monsoon_region, scale=500).get('NDVI')
I don't know if I am doing this right by using a scale of 500. But the page https://developers.google.com/earth-engine/apidocs/ee-image-reduceregion says that
scale Float, default: null A nominal scale in meters of the projection to work in.
and the data (https://developers.google.com/earth-engine/datasets/catalog/MODIS_006_MOD09GA) is at 500m