Tagged Questions

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

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8 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 ...
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0answers
34 views

Python script for dark object subtraction on Landsat 8 Imagery

Does anyone know of any python scripts that will allow me to conduct such a process? I am limited to open source software and have minor experience in Python.
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0answers
47 views

QGIS 2.4.0-Chugiak: How to produce raster colour map

By carefully deriving the NDVI values from Landsat Band 3 and Band 4 after doing atmospheric correction by applying DOS1 method in semi-automatic classification Plugin QGIS, I was to calculate the ...
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0answers
30 views

Converting LANDSAT-8 TIFF to matrix, data frame, or SpatialGridDataFrame formates

I need to correct the reflectance values of LANDSAT-8 data for steep terrain and find it too tedious and clunky in ArcGIS. The data I have is: LANSDAT-8 DEM (ASTER) Slope and aspect (Derived using DEM ...
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2answers
42 views

automatically geo- and ortho- rectify raw Landsat data using DEM

I have a dataset of 20 Landsat scenes (MSS, TM, ETM+) for 20 years (one scene per year). Scenes are in WGS 84, EPSG 32634 coordinate system and I can easily project = geometrically correct them to ...
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1answer
25 views

Are there free maps available that can show me land planted with oil palm?

Currently I am taking gps coordinates of oil palm plantations in Africa. I'm putting the waypoints in a GIS program but the free basemap provided isn't always giving high resolution images, making it ...
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1answer
35 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 ...
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1answer
39 views

Automatically georectify raw Landsat scenes

I am working with 20 raw Landsat images downloaded from GloVis, in WGS 84 (EPSG 32634) coordinate system. I need to geometrically correct them to S_JTSK (EPSG 5514). Usually, georectification is done ...
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0answers
35 views

Possible to use same signature file to classify images from different years?

I have Landsat images for the same area over 20 years (one photo per year in same season). I would like to detect changes occured in forested area like clear-cut and bark beetle outbreak over time. I ...
3
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1answer
98 views

Using GDAL in python to stack Landsat bands

I am processing a large amount of landsat data. Landsat scenes ship as a collection of tiffs- one file for each spectral band, plus a bunch of masks. I need to stack some of the bands into a single ...
2
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1answer
75 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 ...
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1answer
27 views

Apply regression equation to Landsat ETM+ image

I have sample points in an Excel file with XY coordinates and canopy density. I also have a Landsat ETM+ image. All points are collected from the same area as in the image. I exported all sample ...
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1answer
47 views

Canopy density & NDVI Regression using ArcGIS for Desktop?

I have a Landsat ETM+ image, I also have 200 sample points with coordinates,canopy density, different band values and NDVI values. If I build OLS model I only got sample points regressed. How can I ...
3
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0answers
34 views

At surface reflectance values

I have calculated at sensor reflectance for a multispectral image and preformed atmospheric correction. The reflectance values for the visible and NIR bands are between 0.2 to 0.01 for surface eg veg, ...
3
votes
1answer
52 views

Merge different Landsat scenes in Grass GIS

I am new to Grass GIS, and I really need some help in solving this issue. I have 17 scenes from Landsat8 covering an area. I have created color infrared images of bands 5,4,3 and now I want to merge ...
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1answer
57 views

Convert Landsat image to polygon

I downloaded Landsat image and used composite band toolbox. Now, I produced color map but I need to create boundaries across urban area. Is there any way to create polygons among that area and how?
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0answers
63 views

Plotting Bare Soil Line on landsat data in RStudio?

I am using RStudio with landsat package for computing and plotting the Bare Soil Line (BSL) on landsat tif image running on my HP Pavilion i7 laptop. The codes for running the BSL() function is as ...
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1answer
56 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 ...
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1answer
110 views

Best Landsat band for forest classification?

Using Qgis and the Semi-Automatic Plugin for Classification, which are the best Landsat bands to use to classify trees species (in central Argentina)? In Landsat 5, 7 and 8?
3
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1answer
54 views

What's this line in Landsat MSS image?

I have a Landsat MSS image file that contains a vertical string of incorrect pixels. Does anybody know what this might be?
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2answers
59 views

Landsat images with more than 3 colored bands

I’m looking for a website where I can find Landsat images (or similar to it) with more than just 3 color bands. http://glovis.usgs.gov/ only gives me 3 bands. Is there a way to obtain more band? ...
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2answers
38 views

How to calculate regrowth area?

Thanks to Best Landsat-5 TM band combination for detecting fire scars I am able to calculate burnt area in an absolute way (Normalized Burn Ratio). Does a ratio or delta operation exist to calculate ...
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1answer
32 views

Determine changes in land cover of isolated features over time?

I have a a study area of 2 Landsat scenes from 2013 which were classified for a specific natural community, and these areas have been isolated and extracted and digitized into vectors so that they can ...
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2answers
308 views

Best Landsat-5 TM band combination for detecting fire scars

I am looking for the best band combination with Landsat 5 imagery to detect fire scars.
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1answer
155 views

Cloud Removal from Landsat Data

I'm trying to remove clouds from Landsat 5,7 and 8 data. I'm also trying to do this using only open source options, avoiding ArcGIS. I'm familiar with python and have some QGIS experience. Originally, ...
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0answers
50 views

Script to stack multiple landsat bands in different folders

I wanted to find out if there is a possible script I could use to stack landsat bands into a single image, and then apply that stack command to multiple folders (I have about 100 landsat scenes that ...
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1answer
100 views

Using gdal merge correctly?

Currently trying to use gdal_merge within qgis to stack three raster bands, the command it's showing is like this: gdal_merge.bat -separate -of GTiff -o out.tif "LC80190302014126LGN00_B4.TIF" ...
2
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1answer
182 views

NDVI time series in R — how do I create a time series object from a data frame?

I am doing a time series analysis of NDVI using the bfast package in R. Bfast requires a time series (TS) object. I have successfully created a data frame with the NDVI at various point locations ...
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2answers
140 views

Calculate actual Landsat image corner coordinates to derive azimuth (heading)

This is the continuation of an unsolved problem I had (see this thread if you like). I have a Landsat image and I would like to estimate the satellite azimuth for my location. As the satellite follows ...
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0answers
42 views

time processing

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 ...
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0answers
186 views

Use a Python script to stack layers from multiple directories and produce multiple outputs in ERDAS

I am using ERDAS Imagine 2013 and am trying to create a Python script that takes lists created in another script containing the path to each scene's raw data folder and base image ID's (for example ...
0
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0answers
34 views

global pseudo true color landsat mosaic available for download?

Is there a global pseudo true color Landsat mosaic available for download at no charge? Something that was derived from the GeoCover 2000 data set? It doesn't have to be 15 m, 30 m would work, 60 m ...
2
votes
1answer
204 views

How to use the same ROI for multiple LANDSAT images in ENVI?

Suppose that I have 3 landsat images with the same datum ( WGS-84 ) and projection system ( UTM, Zone 39N ) as follows: TM LANDSAT 5 image for July 1987 ETM+ LANDSAT 7 image for July 2001 OLI_TIRS ...
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1answer
55 views

Lat/lon of pixel inside Landsat scene

How do I find the lat/lon of each pixel inside a landsat scene. Either the equations for converting i,j to lat/lon or just a bunch of files, one for each scene. Background: I have downloaded a bunch ...
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0answers
43 views

landsat with C# or Java

I have imaged data about landsat8 satellite. These are raster data, i want to process to take out the temperature of each region (geometry). I can do this in postgresql, but i don't want to store the ...
3
votes
1answer
111 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 ...
4
votes
1answer
270 views

Estimating Landsat 7 azimuth (heading)

I am trying to understand if the Landsat 7 satellite ETM+ orbit has any significant azimuth or if it could be assumed as 0° (as it is not a pointable sensor). I searched in the web but could not find ...
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0answers
53 views

How to select MODIS pixels with 80% homogeneous landcover from landsat classification?

I have a complex landcover classification for a landsat scene at 30m spatial resolution. Includes about 600 land cover classes. There is a fair amount of clumping per group. I have a MODIS EVI 16 day ...
3
votes
1answer
112 views

Estimate forest stand height from Landsat imagery?

Is it possible to estimate the height of forest stands using optical (preferably Landsat) imagery? I came across this article while researching this, but it's over 20 years old and there doesn't ...
0
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1answer
75 views

Georeferencing an aerial image based on satellite imagery

As part of a bigger project I need to georeference an aerial image based on a landsat image downloaded form usgs. I use qgis. can I somehow place the layers on top of each other and mark certain ...
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0answers
54 views

How to perform image classification with SemiAutomaticClassificationPlugin and BIP files?

I have multiband satellite images BIP format, Landsat TM/ETM containing 7/8 bands respectively along with a separate header file, some of them corrected by nearest neighbour classifier. I'm working ...
1
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1answer
421 views

Landsat Observation Zenith and Azimuth Angles

I am doing a project with Landsat which needs to find out 2 Landsat images of the same area for different time, have both the same observation zenith and azimuth angles. But I can not find any ...
1
vote
2answers
121 views

Matching Landsat 8 with previous Landsat images

I am working with Landsat 8 in ENVI. My image's dimensions are 8921 x 13131. I need to apply a forest mask to this image with dimensions of 8805 x 12321. I try to resize an image, but it doesn't work. ...
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2answers
120 views

Programmatically Downloading Landsat Images

There was a very similar question to this one here , but it specified Landsat 8 images; I'd just like to be able to download ANY landsat images, given latitude and longitudes as inputs. Just wanted ...
1
vote
1answer
167 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 ...
1
vote
2answers
518 views

Extract the spectral signature of Landsat 7 and Landsat 8

I have some polygons and I want to extract the spectral signature of the adjacent satellite images. The satellite images that i use are the NDVI from Landsat 7 and 8 and I want to compare the spectral ...
2
votes
2answers
368 views

LANDSAT Image classification and open source solution(s)

I have some experience with ERDAS IMAGINE in doing some supervised/unsupervised LANDSAT imagery classifications and now find myself in the position of needing to do the same but without the access to ...
1
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4answers
113 views

Looking for simple software to compare two Landsat Images

At uni I used ERDAS imagine to view two rasters at the same time and it had various viewers for comparing them. I'm looking for something that has a slider so that I can see the differences between ...
1
vote
1answer
183 views

Floating point calculations in QGIS

How do I manage floating point calculations in QGIS? I have carried out 3 consecutive calculations on landsat bands. I end up with 32 bit floating point rasters on which I can't carry out a 4th ...
3
votes
2answers
235 views

cloud shadow detection

I am trying to detect cloud shadows in Landsat images. I came up with producing good shadows and cloud masks. Now I'd like to implement my cloud mask adding cloud shadows. Do You have a good idea to ...