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

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26 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 ...
4
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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 ...
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0answers
4 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, ...
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0answers
13 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 ...
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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 ...
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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 ...
2
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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 ...
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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
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2answers
108 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?
2
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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 ...
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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 ...
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 ...
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
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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.
1
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1answer
54 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
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 ...
4
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2answers
81 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 ...
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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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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 ...
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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 ...
2
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0answers
183 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 ...
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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 ...
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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 ...
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0answers
28 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 ...
0
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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 ...
0
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1answer
46 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
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1answer
95 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
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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
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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 ...
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0answers
58 views

setting null values to 0 Landsat 8 Grass 7.1

I am working with Landsat8 images and need to run the albedo function in Grass 7.1.svn. In order to do this, I need to set the null values to 0 to eliminate the black border around the images. This ...
1
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1answer
122 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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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- > ...
0
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0answers
238 views

QGIS 2.4; How to convert float raster to integer raster

I am using Normalize difference vegetation index (NDVI) derived from the landsat satellite band 3 and band 4 that have float values ranges from -1.0 to 1.0. I want to see the attribute table that is ...
6
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1answer
112 views

Confidence in pan-sharpened classification?

I pan-sharpened one Landsat Image on ERDAS using the resolution merge resource, with brovey transform and nearest neighbor techniques. But I was told that in terms of land-use classification, it would ...
1
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1answer
67 views

i.landsat.toar doesn't Work With Band 6 of Landsat 7 in Grass 7

I'm facing an issue when running i.landsat.toar with a Landsat 7 image, here's the list of files: LE70010752014040CUB00_B1 LE70010752014040CUB00_B2 LE70010752014040CUB00_B3 LE70010752014040CUB00_B4 ...
3
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1answer
118 views

It is possible to verify landsat reflectance values?

My question is really wide today, as I am still beginner in Remote sensing. I´ve asked a GRASS programmer to prepare for me Landsat reflectance values from raw DN values (1 scene per year from 1987 to ...
0
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3answers
370 views

Save rasters created by loop operation to different directory?

I have a set of rasters. I crop them all using FOR loop. Then, I want to save new-created rasters in new directory, not in my actual directory. For one raster it is easy: writeRaster(raster1, ...
4
votes
1answer
625 views

How to import multiple stacked raster images in R?

I have (I suppose) wery easy and silly question but I can´t really find my answer... I would like to import all multiple mosaic rasters (each mosaic is composed by 7 layers) from indicated folder into ...
2
votes
1answer
204 views

Java packages for landsat 8 processing?

I am looking for the same packages as outlined in this question - Are there Python packages for Landsat 8 processing? except that I want these in Java. Any Open Source packages out there that can do ...
9
votes
2answers
325 views

Methodology for Hansen classification of Global Forest Watch?

I have just discovered amazing Hansen´s classification about forest loss and re-growth, available at http://www.globalforestwatch.org/, published in Science, 2013 as: Hansen, M. C., Potapov, P. V, ...
2
votes
1answer
115 views

ENVI 5: High resolution export of multiband imagery

I have to export some multiband Landsat imagery (Landsat channel combination 543) in high resolution in ENVI 5 for a Figure which I later will edit in Adobe Photoshop and Illustrator, best would be ...
1
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0answers
54 views

Georeferencing multispectral data using ArcGIS Desktop?

I often have to georeference Landsat data image to map (often raw data without geometric corrections). The way I am doing this is to open up one channel and set my GCPs and save them into a txt file. ...
2
votes
1answer
92 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 ...
1
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1answer
150 views

Which DOS method use to convert at-sensor radiance to at-surface values in GRASS (landsat data, i.landsat.toar modul)?

I am trying to calculate surface reflectance values from raw Landsat DN data downloaded from GLOVIS. I have imported Landsat data in GRASS 6 with header by i.landsat.import and reprojected the scene ...
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0answers
21 views

About of low and high gain in Landsat for illuminate the scene

I don't know because after of make the calibration (only TOA) the false color composition (543 in Landsat 7) yet is different between 2 scenes. A scene looks opaque and another is clear (both are of ...
1
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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 ...
2
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0answers
156 views

Resample Landsat 8 to 60m Resolution

I have two Landsat images for the same study area. One of them in 1975 (Landsat 2 MSS with 60m resolution) and the other in 2014 (Landsat8 OLI with 30m resolution). I want to do change detection ...
2
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1answer
222 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 ...