A series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey.

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-3
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0answers
21 views

How to calculate areas of NDVI with Qgis? [duplicate]

How do I calculate the area of the pixel values of NDVI with QGIS? Excuse me, I do not speak English. Ya calcule el NDVI de una imagen Landsat con Qgis, ahora Necesito obtener las Areas de cada ...
0
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1answer
137 views

GRASS i.landsat.toar returns empty raster

I am trying to use the GRASS module i.landsat.toar. Currently the files created are empty and it spits out: So it seems that it is not picking up something? The location is set to the extent of ...
3
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0answers
28 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, ...
0
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0answers
15 views

gdalwarp, pyproj and gdal-osr have different transformation output

I would like to transform Landsat 8 scenes from the native UTM to the official Hungarian spatial reference system. My problem is that pyproj.transform and osr.CoordinateTransformation have the same ...
0
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1answer
36 views

Why do pixel (cell) values change for 32 real NDVI values when taking from Multispec to QGIS?

Landsat 5 values change from normal NDVI -1 to 1 when created in Multispec as a 32 bit signed data image. When adding the raster layer in QGIS, the value range changed to 0-255. How does one ...
6
votes
3answers
372 views

How to easily identify/classify coniferous forest from one date Landsat image?

I am pretty new in remote sensing and I am trying to identify/classify coniferous forest cover from single date Landsat scene. According to my preliminary web research I have these possibilities: ...
4
votes
1answer
41 views

What is the “t” in i.landsat.toar

I'm using GrassGis 7.0.0 for Landsat imagery. In the description of i.Landsat.toar under dos3 and dos4 is: TAUz = exp[-t/sin(e)] What is "t"? I cannot find any description about what it is. Can ...
2
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1answer
35 views

Difference between a spectroradiometer and multispectral sensor

Let's take as an example of a spectroradiometer MODIS, and as an example of a multispectral sensor the Landsat8 (OLI). What is the difference between these two sensors? Should we compare a ...
1
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1answer
416 views

Masking clouds with Fmask

I have been trying to mask clouds with the quality control band with landsat 8 imagery. The problem I continue to run into is that the quality control bands mistake tops of buildings and concrete as ...
1
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0answers
5 views

Error executing GRASS function i.topo.corr from R [closed]

I am attempting to topographically rectify Landsat data using the i.topo.corr GRASS function from within R using the rgrass7 package. My code is as follows: execGRASS("i.topo.corr", flags = "i", ...
2
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0answers
19 views

Important to perform atmospheric correction when attempting to identify coral reefs?

I want to identify coral reefs using multi-temporal Landsat data and Lyzenga's Transformation method. In relation to pre-processing the image, should atmospheric correction be done or not? If not, ...
0
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0answers
39 views

DEM input problem using ARCSI Landsat 8 batch processing

I'm trying to use ARCSI in Linux to process a batch of Landsat 8 images. I'm using the arcsibuildcmdslist.py to build the arcsi.py final command. I'm having problems in the input DEM ...
0
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0answers
14 views

Difference in the definition of the radiometric resolution between a SAR and an optical sensor

Why is the definition of Radiometric resolution in Synthetic Aperture Radar (SAR) different from its simple definition in optical sensors (although both products are images in a numerical format or ...
0
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0answers
19 views

Geometric correction using topographic maps?

I am researching LULC change detection using Landsat 7 etm + image in 2000 and Landsat 8 image in 2014. Both are L1T images. Do I need to do geometric correction using topographic map for my study ...
1
vote
1answer
294 views

Is Landsat 4-5-7 L1G geometric corrected?

Im using Landsat L1G for our project and need L1G to be geometric corrected for later use. One thing I know for sure that L1G need to be employed a Digital Elevation Model (DEM) for topographic ...
2
votes
1answer
223 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 ...
2
votes
1answer
60 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 ...
1
vote
1answer
73 views

Spectral Signature Extraction using landsat 7 and MODIS

I am working on differentiating cocoa plants from other vegetation types using 4 epoch bwt 1980-2010. I need to extract the spectral signature for cocoa plants and other known features. I plan using ...
1
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0answers
18 views

Change detection between two Landsat scenes? [duplicate]

I want to do time series analysis and find change in NDVI. I have rasters where each pixel is represented by some value at a time. Also I have same thing but represented by points. And I would like ...
2
votes
2answers
112 views

How to atmospherically correct Landsat 8 data?

What is a simple way to atmospherically correct Landsat 8 data using Erdas 9.3 or ArcGIS 9.3?
1
vote
2answers
98 views

NDVI from Landsat8 LandsatLook images

I have downloaded landsat image from this site and now Im wondering if i can get NDVI index from it. In raster calculator I have only 3 ranges, shouldnt be four? Or am I doing something ...
2
votes
1answer
38 views

Landsat Surface Reflectancce product Python packages

I have to work with numerous Landsat surface reflectance product that I downloaded from http://landsat.usgs.gov/CDR_LSR.php. The product comes with a QA data with information on clouds and shadows ...
0
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0answers
46 views

Calculating climatological albedo using MODIS satellite images?

My question is based on the paper Using NOAA AVHRR and SPOT VGT data to estimate surface parameters: application to a mesoscale meteorological model. The authors have calculated albedo, surface ...
16
votes
4answers
4k views

Which remote sensing satellite is best used for vegetation extent mapping

I'm currently writing an assignment for my remote sensing class and while I think I have correct answer was wondering what people who do this stuff for a living think. The question is: which ...
1
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2answers
22 views

Unable to set raster surface resolution in ArcScene?

I have a 3-band subset of a Landsat image which I want to display in ArcScene (of ArcGIS version 10.2.1). The image is 30 meter resolution and I am draping it on a 25m resolution Aster DEM. But have ...
0
votes
1answer
13 views

Move Landsat 7 Image in Grass 7

I got 2 landsat 7 images from the same place but different date of adquisition, image A is well placed, but image B is shifted about 1500 meters east and 14700 meters north. I need to use both images ...
0
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0answers
20 views

Landsat 7 SLC off gap-filling

Please suggest me how can I fill the gap of SLC off Landsat 7 data band 8 that is panchromatic band. Also suggest me is there any method to fill the gap of all other bands too.
0
votes
1answer
101 views

Creating histogram/statistics/scatterplot by classification tool in ArcMap?

I'm currently working on a land cover classification with Landsat 8 imagery. I already subjected the imagery to pre-processing (atmospheric and topographic correction) and I mosaiced two images. Now I ...
1
vote
1answer
55 views

The stability of randomForest models after increasing predictor variables

With reference to the posts: Incorporating terrain data to predict canopy cover using randomForest in R and Random-Forest Classification of 10cm Imagery for species-distribution in R (no point-shapes) ...
0
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0answers
51 views

Time processing in GRASS?

I am computing NDVI for Landsat TM in grass 6.4.3 in raster map calculator, and time processing is many hours and finally tke message is "failed". trying to find a solution I discovered that it ...
1
vote
1answer
123 views

Export of group = multiband raster to another format not works in GRASS

I am really new in GRASS and my question is really basic but I dont realize where I am wrong. I have a set of single layers in my PERMANENT from some Landsat images (1 landsat = 7 one layer ...
0
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0answers
12 views

fit polynomial function on spectral data

I want to fit a polynomial function (max. 3rd order) on each raster cell over all my spectral bands (Landsat 1-7) creating a new raster(stack) representing the coefficients. I got my data (including ...
3
votes
2answers
133 views

Is it possible to highlight water steam sources on Landsat 7 image?

I am trying whether it is possible to view hot steam sources like power plant cooling towers and resulting cloud using satellite images. I was advised to try Landsat (needed free data for initial ...
2
votes
1answer
323 views

Extract elevation data from Landsat / MODIS imagery?

Just curious, have anyone tried to extract elevation data from LANDSAT or MODIS imagery? So far, I came across one journal by Toutin who did so using adjacent LANDSAT 7 imageries. Results seem pretty ...
4
votes
2answers
82 views

Random Forest to estimate land use in past with Landsat

I am new in Machine Learning and in R. I am working in my Master thesis. I am trying to estimate the LULC of the years 1984, 1990, 2000, 2011, 2014 for characterizing the forest dynamics. I have for ...
0
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0answers
13 views

Using QGIS to create a single # band raster Image [duplicate]

I recently downloaded some Landsat Images. They are in GeoTIFF format. The images are in the different bands. How can I combine them for example if band 1 is Red , band 2 is green and band 3 is blue, ...
0
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0answers
76 views

Mosaic LANDSAT 4 Image in ERDAS IMAGINE

I am trying to do Mosaic in Erdas imagine. I have three tiles of Landsat data: one is Sept89 others two are March90. I am using Weighted Seamline method and Histogram Matching for the mosaicing but ...
3
votes
1answer
667 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 ...
2
votes
0answers
184 views

RGB satellite image in Python with Basemap

Can anyone recommend a workflow or python library that will let me work with RGB images and BaseMap (or something equivalent - could be CartoPy). I have Landsat 8 images, and can load one in python ...
0
votes
0answers
46 views

Is Images Concatenation in the Processing toolbox working in QGIS 2.8?

I want to make a single multiband .tiff image out of 7 bands that I have downloaded from USGS Earth Explorer and for that I used images concatination in the processing toolbox. I have loaded the 7 ...
1
vote
0answers
44 views

Landsat Data to Map Slums in India

I am working on a project to answer the following geographic question: How much have slum areas increased in Mumbai, India, since the 1970's (or earliest data). I have downloaded LandSat imagery and ...
1
vote
0answers
29 views

How do I use Multispec for Landsat data?

It seems that I only can use the Clustering if I want to cluster only one band data.. If I open up more than 1 band (in one image), the cluster toolbar is disabled? optional: Is there any free ...
3
votes
2answers
498 views

Cloud/Shadow Masking: How to shift a cloud mask in Erdas/ArcMap/Py Script

I have the task to mask out cloud cover in approximately 20 landsat 8 scenes. Creating the cloud mask for the "white part" is easy, but I need help in addressing the clouds shadow. General ...
0
votes
1answer
55 views

Resolution problem

I have a Landsat TM image and in QGIS I used Clipper to crop my image. Then, I tried to reprojected it via Warp (Reproject) and the pixel size goes 29.9936,-29.9936. I do not understand why this ...
4
votes
3answers
225 views

Is there a FTP to get Landsat images?

I need to automatically fetch Landsat images and for that it would be handy to access a ftp with images available. Does such ftp exist? Can I access it? Ultimately I want to get cloudless images.
2
votes
1answer
96 views

Using iterator in ModelBuilder for groups of rasters

I'm trying to do some raster calculations on Landsat imagery in ModelBuilder. I'm calculating basic indices using Raster Calculator followed by Zonal Statistics. The resulting tables are merged ...
0
votes
1answer
47 views

Landsat oli mosaicking for LULC classification

I have to classify land use land cover data for western ghats- 1,07,770 sq km area.The landsat images for the area cover 15 tiles . I have to use minimum cloud cover images . But for the same the ...
0
votes
1answer
96 views

Removing salt and pepper effect

In a land cover raster (categorical map) that is a product of classified satellite image, what is the best way to remove "salt and pepper" effect from the image after classification. I am not ...
1
vote
2answers
251 views

Band conversion from different landsat imagery (Landsat 5,7 and 8)

I am mapping mangrove areas over time (from 2003 to 2014 ) and thus use different landsat imagery. Band combinations i use and am satisfied with in Landsat 7 include band: 4,5,3 4,5,1 7,4,2 when using ...
0
votes
1answer
28 views

Geomatica Wavelength Landsat 7

im working with Landsat 7 images and Geomatica Focus. I want to use the spectral plot to distribute the different wavelengths (spectral signature) of my image bands. In the tool(right click- > ...