Questions tagged [normalized-difference-water-index]

17 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
2
votes
0answers
55 views

Printing NDWI and NDVI comparision graph

Trying to print the chart for both NDVI and NDWI function addNDVI(image) { var ndvi = image.normalizedDifference(['B4', 'B3']); return image.addBands(ndvi); } ...
1
vote
0answers
42 views

Obtaining time series of water extents per plot using landsat NDWI data available on GEE

I wanted to obtain a monthly time series estimate of the water surface for each of 67 survey plots (500m circles). However, I could not figure out how to correctly code this in the google earth engine....
1
vote
0answers
34 views

How to convert NDWI into vector and export it?

I am working over a collection to calculate NDWI. Now I want to convert each NDWI over the collection to vector and export it. Following code is being used. a function defined for masking function ...
1
vote
0answers
32 views

Cloud Shadow interferring with NDWI Analysis

I'm working on surface water identification in Northern Kenya. I'm using Landsat 5TM and Landsat 8OLI data in ENVI 5. I've masked clouds using the QA band (although have also tried the fmask tool- ...
1
vote
0answers
146 views

PlanetScope NDWI calculations

I am trying to calculate NDWI for a PlanetScope image scene. I currently have 2 products: one is the "3B_AnalyticMS_SR.tif" and the other is the "3B_AnalyticMS.tif" product. I believe the former is ...
1
vote
0answers
42 views

How to export NDWI images one by one?

I am using GEE and I'm pretty new with this engine. I'm trying to download several images from Landsat collection. I provide the script for you. Here is my question: How can I download each NDWI ...
1
vote
0answers
77 views

Comparing NDWI regions with a given shapefile Google Earth Engine Python?

With the code below, I computed the NDVI, NDWI and NDWIMOD indices of a R.O.I. in order to detect water areas in that R.O.I. Now, my goal concerns to compare the water areas with a given shapefile ...
1
vote
0answers
59 views

Unable to use ee.Kernel Google Earth Engine pyhon API

I'm trying to use the ee.Kernel Google Earth Engine pyhon API in the following code: import ee import ee.mapclient ee.Initialize() ee.mapclient.centerMap(15.88, 41.78, 10) def maskS2clouds(...
1
vote
0answers
19 views

Performing unsupervised classification using ArcGIS Desktop?

How to distinguish between water bodies and clouds using unsupervised classification in sentinel 2? When i used NDWI and NDSI both are same objects.
1
vote
0answers
120 views

Clip a Mask (NDSI) from another Mask (NDWI) in GEE

I have created a mask of Normalized difference Snow Index (NDSI) in the late winter using a combination of Landsat 5,7,8 imagery and I would like to only keep a remaining land features by clipping out ...
0
votes
0answers
32 views

Landsat imagery corrections

I have downloaded Landsat collection 1 Level 1 imagery (Landsat 4,5,7 and 8) from https://earthexplorer.usgs.gov/. I would like to know that do we have to apply some conversions or corrections before ...
0
votes
0answers
29 views

Overcoming error : classified: Layer error: Image.reduceConnectedComponents: Label band must be integer valued, found type 'Float'

with following code , I am getting error message https://code.earthengine.google.com/15a22656f680c38ff0bf10afd2747c5f classified: Layer error: Image.reduceConnectedComponents: Label band must be ...
0
votes
0answers
13 views

Creating and Labeling time series (features)

I am trying to carry out crop type identification using optical remotely sensed data of Sentinel-2A. I am new to both fields (remote sensing and machine learning) and I want to use time series (NDVI, ...
0
votes
0answers
23 views

NDWI from Landsat-8 imagery

I am trying to calculate NDWI from Landsat-8 Band3(range:-113 to 11785) and Band5(range -89 to 12960) but the range of the resultant NDWI image is not valid (range: -215.181 to 1151.02). What is the ...
0
votes
0answers
91 views

How can I subtract one layer from another layer in Google Earth Engine?

I calculated NDSI and NDWI, NDWI disguises my water. I need to calculate the area of ​​snow, but I think that he considers all the snow and is masked. So I need to subtract (SNOW-WATER). And then ...
0
votes
0answers
38 views

select waters pixels in GEE as magic wand tool

I am interested to map small water bodies in a desert . I used Gond method described in an article entitled "An Assessment of Surface Water Detection Methods for Water Resource Management in the ...
0
votes
0answers
59 views

How to average the NDDI index for a map in GEE

In previous codes I was able to generate the NDVI average, but since NDDI is a sub-index I would like to know if anyone would be able to generate this NDDI average in GEE https://code.earthengine....