All Questions
Tagged with ndvi remote-sensing
101 questions
19
votes
3
answers
3k
views
Alternative vegetation indices
I have been using NDVIs with limited success to identify trees in the central Great Plains region of the USA. The problem I have been encountering is that reflectance from farm fields/pastures have ...
- 51.8k
10
votes
1
answer
1k
views
Landsat level-2 data comparison
I'm doing a temporal analysis of NDVI and temperature over 17 years, necessitating data from Landsat 5,7, & 8. I'm interested in using level-2 Landsat data available from https://espa.cr.usgs.gov/...
- 425
9
votes
1
answer
9k
views
Reprojected MODIS NDVI has range from -32768 to 32767, expected -1 to 1
I'm new to StackExchange and to remote sensing. I am working with MOD13Q1 250m 16-day MVCs. My goal is to use NDVI time-series to classify cropping pattern and crop type, then link this data to ...
- 769
8
votes
2
answers
2k
views
Why is there a difference between NDVI using Sentinel 2, in ArcMap & QGIS?
I have been trying to calculate the NDVI for a scene using Sentinel 2 bands 4(red) & 8(NIR).
I first did it in ArcMap and then QGIS.
In both softwares, I used the raster calculator and included ...
- 840
7
votes
1
answer
779
views
Which NIR bandwidth is suitable to Calculate NDVI?
Often we encounter multi-spectral and hyper-spectral sensors offering multiple NIR bands. For instance, the WorldView 3 sensor has 8 MS bands, out of them, two bands fall within NIR region.
Near-IR1: ...
- 1,218
7
votes
3
answers
17k
views
Download high res NDVI imagery
I'm trying to find a good source of NDVI imagery, but I'm struggling to find proper high res imagery, particularly for northern Europe.
Does anyone have references to high res imagery, that is ...
- 335
7
votes
1
answer
5k
views
Difference between Landsat 7 and Landsat 8 TOA reflectance computation
In section 3.1 of this article it is explained how the Top of Atmosphere Reflectance for Landsat 7 and Landsat 8 are computed. The equation for Landsat 8 is not mentioned explicitly, but can be found ...
- 901
5
votes
1
answer
454
views
Determining the best month for discriminating between different vegetation types?
I ordered and downloaded several (Surface Reflectance) Landsat 5-8 images from USGS Earth Explorer with the purpose of choosing a few of them to calculate some Vegetation Indices for each (NDVI, SAVI, ...
- 313
5
votes
2
answers
1k
views
Applying pixel reliability mask to time series MOD13Q1
I am working with a 23-band GEOTiff in which each band is a 16-day MVC MODIS NDVI image. The MODIS .hdfs include a "pixel reliability" image with the following values:
[-1]: Fill/No Data-Not ...
- 769
4
votes
4
answers
4k
views
Where to download 4-band NAIP imagery for California?
I've been trying to find orthoimages with 4 bands for a couple of counties in California. I managed to download some from the GeoSpatial Data Gateway from the USDA (NRCS), but they all only have 3 ...
- 55
4
votes
2
answers
2k
views
Classify forest with NDVI from Landsat 8 and 7
I'd like to calculate the NDVI for multi-date satellite images of Landsat (7,8) to perform a change detection on the deforestation of the Amazon rainforest. I already acquired surface reflectance ...
- 55
4
votes
2
answers
909
views
Landsat 8 appears to be "greener" than Landsat 5?
I noticed something strange in my NDVI time series. Here I plotted NDVI for some geometries of interest in European countries between 1985 and 2020.
You will see there is a noticeable jump in NDVI ...
- 87
4
votes
1
answer
742
views
Why getting wrong NDVI values resulted from scaled reflectance in ArcMap?
I have made atmospheric corrections to my Landsat 8-OLI raster using 'ENVI FLAASH' having surface reflectance values scaled between 1-100.
In ArcGIS I am using simple expression to compute NDVI ...
- 1,218
4
votes
2
answers
800
views
How to reduce number of raster bands of a RGB picture?
For my Master Thesis in Ecology I want to calculate an NDVI Index.
The tricky part is, that I don't have sattelite pictures with bands and so on, but RGB pictures. The pictures where taken with a ...
- 43
4
votes
1
answer
1k
views
NDVI image processing
I am trying to get a NDVI image from an RGB + NIR image captured by a modified Cannon S110 camera bought from Event38 along with a 3DR Iris+ drone link
The image captured with the camera looks like ...
- 41
4
votes
2
answers
1k
views
Classification, Change detection and NDVI Using (landsat2 MSS), (landsat5 TM), (Landsat7 ETM+) and (Landsat8 OLI)
I have 5 Landsat images for the same study area. One of them in 1975 (Landsat 2 MSS), two in 1985 and 1995 (Landsat 5 TM) and one in 2005 (Landsat 7 ETM+) and the last one in 2014 (Landsat8 OLI). I ...
- 69
3
votes
2
answers
4k
views
Tutorial Vegetation Condition Index
Anybody here can help me regarding calculating Vegetation Condition Index (Kogan,2004) for Landsat?. Specially facing problem in NDVI_max and NDVI_min; which should be maximum and minimum value?
- 105
3
votes
2
answers
4k
views
Do clouds reflect NIR/Red bands
When using Landsat 8 imagery to calculate NDVI, will the NIR and Red bands be affected by cloud cover?
In other words, will clouds produce a wrong NDVI calculation?
- 335
3
votes
3
answers
2k
views
Issue with scaling factors for Landsat Collection 2 Level 2 data when calculating NDVI
I'm trying to calculate the NDVI for a scene, and I've downloaded Landsat 8 OLI/TIRS Collection 2 Level 2 data, which means it has already been processed to surface reflectance.
The scaling factors ...
- 31
3
votes
1
answer
2k
views
Is atmospheric correction necessary when working with multi-spectral indexes?
When you are working with Landsat Level 1 data and calculate indexes, e.g. NDVI, NDBI, SAVI ..., do you calculate them using raw data (pixel DN value), or atmospherically corrected data (surface ...
- 423
3
votes
1
answer
1k
views
Calculate and extract layer of NDVI change in Google Earth Engine
My experience and expertise in Google Earth Engine are super low. My study area is Sundarban, Bangladesh. I have 2 NDVI from 2 years (2016 & 2017). I want to find the vegetation change by ...
- 57
3
votes
3
answers
2k
views
How to remove cloudy pixel from MODIS NDVI (MOD13Q1)
I am using MODIS NDVI product (MOD13Q1) for the vegetation changes study. I want to remove cloudy or bad pixel from MODIS NDVI data. I am not getting any suitable method or software or any program to ...
- 165
3
votes
1
answer
484
views
Determining phenological events based on Greatest increase NDVI approach?
I have a problem with a phenological study. The study area is in temperate zone of Asia. I have been doing phenological research using MOD VI product. I wanted to extract phenological events (onset/...
- 169
3
votes
1
answer
868
views
Better NDVI for Landsat 8?
I'm looking at NDVI changes for an area over 20 years. There seems to be a slight downward trend, however, upon switching from Landsat 5 in 2011 to Landsat 8 in 2013 I'm getting NDVI values that are ...
- 147
3
votes
1
answer
398
views
How to represent seasonal variability in a single global NDVI map?
I have twelve monthly MODIS datasets for a 1 year period (http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MOD13A2_M_NDVI&year=2015) and wish to combine all the data into a single map highlighting ...
- 861
3
votes
1
answer
2k
views
NDVI analysis of LANDSAT 8 imagery in QGIS
I am trying to run an NDVI classification of 2015 multispectral LT8 imagery in QGIS to assess the quality of vegetation cover in regards to habitat suitability for a primate species in northern ...
- 123
3
votes
2
answers
308
views
Vegetation Index for dry and sparse vegetated areas?
I found many different index for the estimation of vegetation cover, but many of them struggle in sparse areas with low vegetation cover, as the soil signals are way stronger than the vegetation ...
- 390
3
votes
1
answer
272
views
Temporal spectral analysis in order to differentiate agricultural/croplands from natural/semi-natural grasslands using remotely sensed data
I am working on a critically endangered bustard species in India (Houbaropsis bengalensis). I need to prepare a land cover map of its 'suitable' grassland habitat across its distributional range. I ...
- 31
3
votes
1
answer
1k
views
Applying savitzky golay filter to MODIS NDVI data
I want to smooth the NDVI MODIS 16 bit integer data .tif for LULC classification. I have timesat 3.1 software on windows but I don't how to apply the SG filter. I am not that good in programming. I ...
- 183
3
votes
2
answers
2k
views
Calculating NDVI using Landsat ETM+ band values
I have sample points (shape file converted from a .xls file which contains XY coordinates,nnx,nny and canopy density) and a landsat etm+ image. First I applied 'SpatialAnalyst Tools>Extraction >Sample'...
- 197
3
votes
0
answers
3k
views
Interpreting NDVI value on water?
There is a surreal thing on my NDVI images. NDVI values on lake is ranging from -0.04 to 0.7. (The lake surrounded by forest and has freshwater). Theoretically, negative value of NDVI is correspond to ...
- 659
3
votes
3
answers
3k
views
NDVI image value changes from -1 to 1 in ENVI to 0-255 in ArcGIS Desktop and ERDAS Imagine?
When i open NDVI image in ENVI, its value is still within the range (-1 to 1).
But when I open this NDVI image in ERDAS and ArcGIS Desktop, its value is 0-255.
What does it mean?
Is the NDVI ...
- 31
2
votes
3
answers
356
views
MODIS temperature and NDVI data?
hope anyone could give me some hints here. I tried to download free MODIS data from their page(resolution 500m, 1km). Im interested in NDVI and temperature data. But when i load the hdf files into my ...
- 567
2
votes
1
answer
3k
views
How to create NDVI map From LiDAR intensity and RGB image
I am new with GIS and I've been looking for ways on how I could create a NDVI map from LiDAR intensity and RGB image. Is there any way I could do this?
I have read that you could create an intensity ...
- 49
2
votes
1
answer
200
views
Fusing Collection 1 Landsat 7 and 8 Surface Reflectance NDVI
I'm fusing L7 & L8 surface reflectance into an NDVI time-series. I'm using the method described in Roy et al. 2016 to convert L7 NDVI to L8 NDVI using a simple regression equation found in table 3:...
- 151
2
votes
1
answer
577
views
Calculating plant proportion Landsat
I have this paper. In equation 2 they are calculating surface emissivity.
I want to ask what is 𝑷v plant proportion?
https://www.researchgate.net/file.PostFileLoader.html?id=...
- 43
2
votes
1
answer
450
views
Landsat Collection 1 Level-1 or Landsat Collection 1 Higher Level?
I want to use NDWI and NDVI index in my study for a time-series analysis using all products available (Landsat 5,7 and 8).
Can I use the product Landsat Collection 1 Level 1 for my analysis or
...
- 41
2
votes
2
answers
451
views
Comparability of Landsats
I have collected data (spectral bands) from Landsat 4-5 and Landsat 8. I was calculating NDVI when I noticed that the two Landsats have different band numbers designated as Red and Near Infra Red (...
- 736
2
votes
1
answer
673
views
Failure in TIMESAT integral calculation
in short: My TIMESAT image-output of the seasonal parameter “Large Seasonal Integral” is wrong. TIMESAT continues to write a file with negative values (as 16 byte Integer) although Parameters should ...
- 311
2
votes
1
answer
993
views
Doing NDVI when nir data is given as 3 bands
I have been provided with two data sets of the same area, one with normal RGB bands and one with NIR data. My problem is that since the NIR data is given as 3 bands, i am not sure how I should ...
- 1,087
2
votes
1
answer
2k
views
Dealing with NAN values in my training dataset
I am new to remote sensing. I am working on a project where I need to perform land use land cover classification. For such a task I want to use machine learning (python).
My features contain 'BANDS' (...
- 471
2
votes
1
answer
522
views
Aggregating/Averaging NDVI across pixels. Arithmetic mean seems bad choice
I need to compute an aggregate index for vegetation density in certain (large) shapes, to assess desertification. I have NDVI data at a high spatial resolution (~100 NDVI-pixels per aggregation shape, ...
- 289
2
votes
1
answer
383
views
Why do UAV-derived NDVI values fall far outside -1 to 1 range after empirical line calibration?
This question was marked as being a duplicate of Landsat8 NDVI values not in the -1 to 1 range but I've posted my question because:
I am not using Landsat; and
there was no explanation of how to ...
- 61
2
votes
1
answer
1k
views
How to interpret Tasseled Cap Greenness for Landsat 5?
I have amassed a few promising literature articles, and looked at the help files for ENVI, ArcMap and PCI, and no one really goes into great depth on how to interpret spectral values for Tasseled Cap ...
- 89
2
votes
1
answer
3k
views
Calculate EVI From Landsat 8 in QGIS [closed]
I have calculated atmospherically corrected reflectance values for Landsat 8.
From that, I am getting correct values of NDVI in QGIS, but for EVI I am not getting the correct values. For some images ...
2
votes
1
answer
1k
views
problem of using TIMESAT to processing MODIS NDVI
I want to use TIMESAT software to analyse time series MODIS NDVI data. Firstly, I use MRT tool to mosaic,subset and project MODIS NDVI data and output data as GEOTIFF format, and save as ENVI standard ...
- 51
2
votes
1
answer
542
views
GEE: projection error when exporting data to a table
I am trying to export some vegetation condition index data calculated from MODIS data on Google Earth Engine to a table, but keep getting the error:
Error in map(ID=3): Image.reduceRegions: Unable to ...
- 861
2
votes
1
answer
493
views
Exporting EVI image on Google Earth Engine with visual parameters between -1 and 1?
I am having an issue with exporting an EVI image with the visual parameters between -1 and 1. On Google Earth Engine (GEE), using the inspector tool, the values are between -1 and 1, but when I export ...
- 21
2
votes
0
answers
482
views
NDVI calculation problem
I have photo created by UAV, and I want to calculate bNDVI:
(NIR-blue)/(NIR+blue)
I have these bands (filter is ok -100%). So using QGIS I have values -0,1-> 0,3 - but bNDVI must be from 0,65->0,...
- 21
2
votes
0
answers
260
views
16-day-MODIS NDVI values seem to be wrong compared to my soil moisture ground data!
I'm using MOD13Q1 product of MODIS for estimation soil moisture. As I know, this product is made up of the maximum value of NDVI of each pixel over 16-day calculated NDVI values. The problem is that ...
- 377