# Questions tagged [ndvi]

Normalized Difference Vegetation Index is used to quickly identify vegetation and its condition in remotely-sensed data.

381 questions
103 views

### r.mapcalculator

I am using QGIS 2.18.25. I'm struggling to use r.mapcalc to calculate the ndvi for a workbook project. R.mapcalculator is shown on the workbook I'm using and seems simpler to use. Is there a plug-in ...
205 views

### Faulty Landsat 5 and 7 NDVI/ EVI archives in Google Earth Engine

For my research, I need to use NDVI or EVI datasets in Google Earth Engine. I found Landsat 5 and 7 datasets (8 day, 32 day, anual) for both. However, no matter which combination of datasets and dates ...
64 views

### NDVI Python image showing inverse

I am trying to calculate NDVI using python and landsat imagery. I am able to calculate ndvi using the following equation: def ndvi(sat, fp): raster = rasterio.open(fp) if sat.lower() == 'l8': ...
344 views

### Data smoothing of Sentinel-2 NDVI time series chart in Google Earth Engine?

I am exploring Sentinel-2 time-series NDVI with Google Earth Engine. In another post I learned how to plot a NDVI time series chart. I know that there are many smoothing methods for reducing NDVI ...
375 views

### Setting values for palette in Google Earth Engine

I am very new to GEE. I have been trying to figure out how to assign different colours to different NDVI values. Let's say, in following code, I want to assign 'red' for NDVI value of 0.2-0.4, 'orange'...
260 views

### NDVI Scaling in Google Earth Engine?

I am trying to download NDVI data from the Google Earth Engine MODIS satellite. I used the following dataset: img = ee.ImageCollection("MODIS/006/MOD13A2") To actually download it, I ran img....
339 views

### How do I convert Digital Number (DN) to reflectance in order to analyze NDVI

I'm working with a mapir nir + red camera meaning that its blue band captures nir light and its red captures red normally. I understand that NDVI is calculated using reflectance values. My question ...
34 views

### Error in smoothing NDVI (BISE) using SPIRITS

I want to minimize the spikes caused by cloud cover (smooth) NDVI timeseries data before applying Savitzky–Golay filter in Timesat. My previous post was also related to timeseries (Interpreting NDVI ...
182 views

### Image Collection minimum and maximum Extraction in Google Earth Engine?

I've wrote this code but it makes error about min and max image? var modis = ee.ImageCollection("MODIS/006/MOD13Q1") .filterBounds(geometry) .filterDate("2000-01-01","2001-01-01") .select("NDVI"); ...
2k views

### Creating Sentinel-2 NDVI time series chart in Google Earth Engine?

I am exploring Sentinel-2 time-series NDVI with Google Earth Engine. In another post (here) I calculated and exported NDVI values from Sentinel-2. Now I would like to create a NDVI time series chart, ...
61 views

### How do I visualize NDVI values?

Currently, I have the NDVI values, and I transformed it from [-1, 1] to [0, 255]. Now my question is how do I visualize either of these value? My first thought is to make a color map similar to the ...
688 views

### Calculating NDVI per region, month & year with Google Earth Engine?

I want to calculate the mean NDVI per region (admin level 3, also called woreda), month and year. So my end result would look something like this: regions year month NDVI ------------------...
173 views

### Image Collection Statistics in Google Earth Engine?

How can I extarct mean of each image collection in google earth engine? for example for this code: var modis = ee.ImageCollection("MODIS/006/MOD13Q1") .filterBounds(geometry) .filterDate("2000-01-01",...
438 views

### Making stack from many images in Google Earth Engine?

Using the code below, I've computed 20 ndvi images for modis data. How can I stack and save them in a single file? var mod13 = ee.ImageCollection("MODIS/006/MOD13Q1") .filterBounds(geometry) ....
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### Does Modis offer MultiYear statistics?

I'm trying to calculate the VCI data for my entire State. I'm using MODIS's 16 day NDVI Average. From this post, I see that I would need to calculate the Min & Max NDVI values for each pixel ...
101 views

### EVI2 value calculated from MODIS MOD09Q1 not bounded by -1 to 1

I'm trying to derive from MODIS 8 day composite MOD09Q1.006 product My formula follows the standard interpretation: EVI2 = 2.5(NIR-Red)/(NIR + 2.4*Red+1) I already know that MODIS bands for NIR ...
339 views

### GEE Export.image.toDrive output not matching bounding box?

I am new to GEE and javascript. Copy-pasting here and there, I managed to put together this code that extracts NDVI from cloud-free Sentinel-2 images on GEE. I created a fusion table from a KML with ...
61 views

### Classification based on NDVI values of two images

I want to find the areas where the NDVI value were higher then 0.4 at the end of April and NDVI values were lower then 0.3 at the end of June. I have tried to make it using below demonstrated script, ...
166 views

### Making subset of Sentinel-2 with rasterio?

I am looking for a solution to my problem with rasterio. I want to download just a specific part of the image from AWS based on lat lon coordinates. Rasterio offers a great tool (window) although it ...
67 views

### Is the resolution of MYD13A2/MOD13A2 ( MODIS 16 day 1km Global Vegetation Indices) erroneous in Google Earth Engine?

The MODIS vegetation indices collection shows a resolution of 111319.4 metres in Google Earth Engine when, in fact, it should be 1000 metres. Below is my code: var Veg = ee.ImageCollection("MODIS/...
98 views

### Incorporating NDVI and texture metrics in OBIA-Supervised Image Classification

Anyone knows step-by-step tutorials for incorporating NDVI and texture metrics in land cover classification with ArcMap? I've been doing supervised classification of Sentinel-2 with the assistance ...
117 views

### Calculating indices such as NDVI or NDSI on Landsat 8 imagery whose pixel type is 16 bit signed integer?

I am trying to calculate an NDSI (Normalized Difference Snow Index) using Landsat 8 OLI level 1 imagery atmospherically corrected in ERDAS ATCOR using raster calculator in ArcMap. NDSI is used to to ...
407 views

### Writing numpy array to rasterio raster file generates empty file

I'm using Rasterio to read GeoTIFF from Sentinel 2 and calculating NDVI, but when I try to save as a new TIF file, the file turns to transparent and empty file. What am I missing? That's the code: ...
471 views

### Exporting an image of NDVI layers

I have calculated the NDVI for my study area. However, I am having challenges to export the NDVI images. I want to export a single image with several NDVI layers. I have tried the mosaic function but ...
62 views

### Mosaic Landsat Scenes for NDVI Generation

I would Like to generate an NDVI map for my study region, which is positioned between three Landsat scenes. Which method suits: 1) compute NDVI for each Landsat scenes and then mosaic or 2) Mosaic ...
414 views

### Google Earth Engine API: How to select an image from an image collection based on NDVI value?

I want to select the image with lowest median NDVI to represent bare ground cover from Sentinel-2 image collection for my region of interest (<5% cloud). I have a boundary file pre-loaded on ...
61 views

### Distance measurement

I have calculated NDVI, now I would like to measure the distance from the places which have more vegetation concentration to low to bare concentration areas. which tool in ArcGIS 10.2 will be suitable ...
102 views

### Dimensions of images given their latitude and longitude for Google Earth Engine

From the point long: 16.499050771335575, lat: -30.882 I want to find the corresponding latitude and longitude values that would result in a 200 km by 200 km square in which the aforementioned ...
162 views

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

Could anyone explain why the vegetation indices are not working in the desert region? I used Landsat 8 image which has been already radiometric/atmospheric corrected. I want to see the fractional ...
41 views

### NDVI values to image conversion

I have a column of NDVI values of several centroid of pixels and relevant longitude/latitude associated with it. I want to convert this table to a raster image in ArcGIS 10.4.1. I know the conversion ...
84 views

### Choosing statistical method for determining different crop types? [closed]

Task: Determining different crop types from satellite imagery. Tools at hand Training data set which includes RGB, longitude and latitude, NDVI and crop type for each pixel (10m by 10m) Test data ...
306 views

### Analyze time series NDVI using bfast

I would like to study a trend of NDVI data for a specific time interval using bfast package. For this final aim, I read about the necessity to convert my data frame into a time series object in R. ...
49 views

### Averaging from several rasters [duplicate]

I need to take an average of several rasters using ArcGIS. Suppose there are 6 rasters and want to have an average of all those 6 rasters. How can I do so?
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### Identifying high NDVI values close to vector lines

I have NDVI raster data and vector line data for the St George Queensland irrigation channels. I am trying to detect irrigation channel leakage using high NDVI values detected on the immediate bank....
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### Computing NDVI in ArcMap from Landsat 8 “Analysis-Ready” Surface and TOA Reflectance Products

The internet is full of various contradictory advice on corrections one can make to get NDVI computed from Landsat 8 to fall between -1 and 1. This is for instructional purposes, so I hope to use ...
379 views

### Performing Radiometric Calibration of Sequoia Imagery?

I recently bought a used Sequoia camera and when I bought it, I was under the impression that the sun irradiance sensor and calibration plate would calibrate all my images in real time and I wouldn't ...
239 views

### Is any map with calculated NDVI available online?

Is there any map which has NDVI calculated? Where can I get highest multispectral satellite image which could be zoom to very large extent?
64 views

### Calculating NDVI of ONLY desired region using ArcGIS Desktop?

I want to Calculate NDVI of my Surrounding Area using Landsat 8. I have Calculated NDVI but it is rather a very big region. Can NDVI be calculated for a small specified region or can I extract my ...
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### NDVI error over vegetated surfaces and water

I performed an NDVI analysis using Qgis 2.18 'Las Palmas' of an area of Landsat 7 (wrs_path 168, wrs_row 061),date 2007-12-25 and Landsat 8 (same path and row) date 2017-12-28. I clipped both images ...
107 views

### NDVI calculation of Color-Infrared Image in Arcpy

I have a color infrared image of an agricultural field. The color infrared image contains 3 different bands; NIR, Red, and Green (order maintained here). To calculate the NDVI, I am currently using ...
74 views

### Purchasing NDVI imagery for South Western England? [closed]

I am working on a project developing an application for livestock farmers where they can monitor their feed using satellite data. The main aim is to calculate the biomass of a field of grass. The ...
68 views

### Saving NDVI TIFF file as txt file in ArcGIS Desktop?

I have to use elevation data (dem.tif) and NDVI data (ndvi.tif) as covariates for regression kriging and I want both these files as txt files. How do I do this?
123 views

### g.getOutputs is not a function while Creating a Chart from a Series

I created a Time Series of NDVI from Sentinel 2 Data, now I want to Chart it, using the following code. I get the error g.getOutputs is not a function I never used g.getOutputs, and from what I read, ...
49 views

### ArcGIS: NDVI average for bare soil

In ArcGIS I have a 3 Landsat NDVI datasets for 3 consecutive months and would like to calculate the mean bare soil (in hectares) for which I have manually worked out to be between the values of 105 ...
165 views

### How to compare 2 NDVI images using python?

I want to compare NDVI of 2 images(TIF) of the same area of interest using python. My end result is to get the region on the image where NDVI is decreased(to depict crop damage). Problem: Images have ...
56 views

### Using Band Math in R Creates Raster with Different Coordinate System?

I am trying to make a simple NDVI raster from a Landsat 8 image (containing bands 2-7). The Landsat image has a Coordinate System of NAD_1983_UTM_Zone_11N (and datum: D_North_American_1983). When I ...
36 views

### How to find Dryest Pixel of an ImageCollection in Google Earth Engine? (Dryest pixel composite)

I want to create a composite with the dryes pixels of an ImageCollection. I know how to make a greenest pixel composite, but I have no clue how to make a dryest pixel composite. Is there a function ...
550 views

### Creating a area time series chart on Google Earth Engine

I'm using Google Earth Engine for a article on my university, and I wanna get the evolution of water area of an water body of my region. For that, I'm using NDVI on time series on GEE. I got the NDVI ...