Hot answers tagged

9 votes

Calculate MSAVI (Modified Soil-adjusted Vegetation Index) in Google Earth Engine

Both ways work just fine and give the same results: There is also a small mistake in the formula in your code - wrong bracket. /...
Gennadii Donchyts's user avatar
7 votes

Why vegetation index, NDVI or SAVI is not working in the desert?

The sensitivity of the normalized difference vegetation index (NDVI) to the soil background and atmospheric effects has generated an increasing interest in the development of new indices. The NDVI ...
Maxima's user avatar
  • 1,701
6 votes

Exporting data with different data types in Google Earth Engine. How to make data consistent to download?

Exporting requires all bands to be of the same type, if you use the function bandTypes(), you will notice indeed differences: B2: signed int16 B3: signed int16 ... NDVI: float ∈ [-1, 1] So to ...
Matifou's user avatar
  • 2,001
4 votes

Soil Adjusted Vegetation Index in ArcPy

Alternatively, you could just calculate it yourself in the raster calculator. The modified version of the SAVI (MSAVI) does not require an L factor and is a bit more stable across a range of settings. ...
Jeffrey Evans's user avatar
4 votes

How to apply a Cloud Mask in a collection?

The problem is in the creation of the cloud mask. Use: var mask =['cfmask']).neq((2,4)) instead: var mask =['cfmask']).neq(4).neq(1).neq(2).neq(3) Value 2 and 4 are for ...
aldo_tapia's user avatar
  • 13.4k
2 votes

How to use conditional statement to reclassify raster in ArcGIS?

You can apply Con on two steps: In the first step, use the original image to convert the values less than -1 to -1 as follows: Con("Original_Image.tif"<-1,-1,"Original_Image.tif") The second ...
ahmadhanb's user avatar
  • 40.7k
1 vote

Calculating Soil Adjusted Vegetation Index (SAVI) in Google Earth Engine

If you look at the band description in the dataset catalog, you'll notice that the the red and NIR band have a scale of 0.0001, meaning the values are between 0 and 10000 instead between 0 and 1. So, ...
Daniel Wiell's user avatar
  • 14.1k
1 vote

SAVI time-series chart on Google Earth Engine

Landsat surface reflectance products are scaled by a factor of 10000. So by setting L=0.5 in your expression for calculating SAVI, you are actually calculating 1.5NDVI (since N, R >> 0.5). ...
korndog's user avatar
  • 1,038
1 vote

Analysing Landsat images using ERDAS IMAGINE and ArcGIS

This notation is terrible in communicating application to a time-series. Keep in mind that the subscripts indicate periods of time so, it is the median of all pairwise comparisons. Because the median ...
Jeffrey Evans's user avatar
1 vote

Determining vegetation health on temporal scale using mean NDVI?

You tried SAVI? What L-factor did you use? Did you try the modified version of SAVI? In an area like Bryce Canyon you will have a huge soil brightness component. I highly doubt that L=0.5 would ...
Jeffrey Evans's user avatar
1 vote

Determining vegetation health on temporal scale using mean NDVI?

you should consider the two aspects of vegetation status apart from each others: due to drought and heat stress, your vegetation could die and, as a result, the extent of the vegetation will decrease....
radouxju's user avatar
  • 49.6k

Only top scored, non community-wiki answers of a minimum length are eligible