Collecting and interpreting information about the environment and the surface of the earth from a distance, primarily by sensing radiation that is naturally emitted or reflected by the earth's surface or from the atmosphere, or by sensing signals transmitted from a device and reflected back to it.

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7
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2answers
129 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, ...
0
votes
0answers
12 views

Remote sensing data for different scales

I'm looking for different satellite data concerning different scales. The first one I'm looking for is remote data for soil sealing and water bodies at a scale of 1:30,000, could be generally ...
2
votes
2answers
43 views

Remove clumps of pixels in R

I would like to remove isolated pixels (or clumps of pixels <9) from my raster image. library(raster) # create some raster data r <- raster(ncols=12, nrows=12) set.seed(0) r[] <- ...
0
votes
1answer
38 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 ...
4
votes
2answers
106 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: ...
3
votes
1answer
176 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 ...
2
votes
1answer
31 views

How to write every raster from a list of rasters?

I have created a list of rasters - "norm" and run a several loops. Now I would like to write every created raster from "norm" (containing 1 layer) into one raster, having its specific name. # I can ...
8
votes
3answers
4k views

Best source for high-resolution satellite images free/low-cost?

I am doing a household survey in Kenya, and I need to ensure that my survey team visits every house within a given area. I've been going to google maps and right-clicking on roofs to get coordinates ...
0
votes
2answers
95 views

landsat 7 images

I want to work with landsat 7 images for land cover and NDVI evaluation. There are strips in the landsat images, and I don't know how to remote them. I have learned methods for gapfill but I don't ...
2
votes
1answer
99 views

Spot 6 - Reflectance calibration

I have a Spot-6 image and the metadata contain 9 values of SUN_ELEVATION (BottomRight BottomCenter BottomLeft CenterRight Center CenterLeft TopRight TopCenter TopLeft). I've used before Landsat and ...
1
vote
4answers
71 views

Automated Forest Change Detection

Using two different time of images in the same places. Can i develop an automated change detection for forest area? What / which are the suitable software to used?
2
votes
3answers
1k views

Atmospheric correction for Landsat 8 in ERDAS?

I am attempting to run some classification on Landsat 8 imagery, however, I need to perform atmospheric correction on the images in order to reveal true spectral signatures. I am using ERDAS, and the ...
6
votes
1answer
109 views

Handling mountain shadows when classifying Landsat 8

I'm trying to classify some area in northern Mongolia using Landsat 8 satellite images from 2013. Since the recordings were made in winter, the sun is very low at the acquisition time. Therefore there ...
4
votes
1answer
60 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 ...
1
vote
0answers
20 views

ENVI: Postclassification, remove pixels of certain size

I did a classification over multiple Landsat imagery in ENVI 5.1, which turned out not too bad (ice and snow in Cyan in the picture below). Now I am about to do a postclassification to filter out ...
4
votes
0answers
43 views

How do I open MOD17A3 in ENVI such that it is properly georeferenced?

I am using ENVI 5.1 on Windows 8. I am trying to open a MOD17A3 (MODIS Net Primary Productivity standard product - L4) .hdf file which I downloaded from the USGS website. I am still a beginner at ...
2
votes
1answer
110 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 ...
3
votes
1answer
298 views

how can i correct atmospherically landsat 8 images?

I am trying to correct atmospherically an image from Landsat 8 with 6s model from grass 7 and 6.4. Because there are no parameters for Landsat 8 yet, I am trying to give parameters from Landsat 7 ...
10
votes
1answer
493 views

How to produce high-resolution DEMs from new Sentinel-1 data?

This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
10
votes
1answer
147 views

Automated detection of tracks

Given an area with depressions in open area from; say all terrain vehicles driving on soft surface. The vehicles will cause parallel depressions (paths) of about 10-20 centimeters in depth and around ...
2
votes
1answer
83 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 ...
2
votes
1answer
443 views

Failed to create signature file

I need some help, because I've no clue how solve this issue the exercise that I'm trying to perform. The point where I'm stuck is 4. "Create signature file as LandsatCompS.sgs". I've done what it ...
1
vote
3answers
232 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, ...
3
votes
1answer
148 views

Pan sharpen Landsat 8 using Grass 7

I have followed this great tutorial on pan sharpening using Grass GIS 7 (I'm using beta 3). Everything in the tutorial seemed to have worked, but my final output is not as expected (pictured below). ...
3
votes
1answer
265 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 ...
1
vote
0answers
28 views

How to create model maker NDBI indice using Landsat 8?

I'm having trouble making the model for NDBI (custom made in ERDAS 9.2) using Landsat 8 image? As a result of running the model I'm getting a white image.
2
votes
1answer
29 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 ...
5
votes
1answer
62 views

Retrieving heights of buildings using remotely sensed data (except lidar)

How can I get the height values of buildings from a certain sector a city without going into the field to collect data? Is there anyway to do via satellite imagery, SRTM, ASTER GDEM or any DEM for ...
3
votes
1answer
37 views

Remote Sensing Indices for urban expansion

Apart from NDBI, could you name a few indices for urban expansion? I have done some search on google but haven't found anything that could help me. Perhaps, What I'm interested is also: ...
2
votes
0answers
27 views

Landsat TM, ETM+: what are radiometric calibration coefficient of each sensor to convert DN to radiance

The Landsat TM Image data that comes with zipped folder contains metadata text file in which all necessary information have been written. In order to further process that data, first DN to radiance ...
0
votes
1answer
20 views

MODIS product MCD43A3 stating 16 periodicity but when downloadad I have files every 8 days

I'm downloading the MODIS derived Albedo 16-Day L3 Global 500 m resolution product. I expected to have a dataset for dates every 16 days. Instead I have datasets every 8 days as can be seen in the ...
16
votes
10answers
9k views

What is the best open source software package for Remote Sensing?

Here are many questions with great answers about open source GIS software. I am wondering, what is the best open source software package for Remote Sensing? I would like to learn it and to use in my ...
4
votes
4answers
177 views

Extracting tree crown areas from remote sensing data (visual images and LiDAR)

I am looking for a method to process a remote sensing image and extract the crown areas of the individual trees from the image. I have both visual wavelength areal imagery, and lidar data from the ...
0
votes
1answer
44 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 ...
1
vote
0answers
41 views

Asking linear regression between NDVI and LST using ENVI

Here I have a problem to calculate a linear regression. I Have two images of NDVI and LST derived from Landsat 8 and want to calculate the linear regression for between them obtaining the dry edge and ...
1
vote
1answer
29 views

Band Issues in Quickbird Satellite data

I procure data from DigitalGlobe (Quickbird Satellite data) for different periods hence data having some different band combination. I have attached an example image to show the problem. I am looking ...
2
votes
0answers
56 views

How is Canada Vector Data (CanVec) hydrology data collected and updated?

Canada is vast and collecting any geographic data must be a monumental task. Natural Resources Canada provides a free access to a comprehensive Canada-wide topographic data now refereed to as CanVec ...
1
vote
0answers
34 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 ...
9
votes
1answer
223 views

Most Effective Format to Manage Aerial Photography for Viewing Only

What is the most effective format to manage aerial photography for viewing in ArcGIS? I manage several datasets of Aerial Photography at a few different companies. I have backups of the original ...
3
votes
1answer
456 views

How to build a confusion matrix for image classification using SAGA or QGIS?

I did a supervised classification of a Landsat image subset using my training data polygons. I used SAGA GIS for that and everything worked out fine. Now I am stuck since I have no clue how to ...
4
votes
1answer
94 views

Identify shadow on Landsat image by Hillshade Tool (spatial analysis) in ArcGIS?

I would like to automaticaly identify shadows on Landsat scene in mountaineus area using Hillshade Tool (ArcGIS 10.1). I have 1 Landsat image from one date DEM (SRTM) from the same area To create ...
4
votes
2answers
58 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
193 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 ...
0
votes
1answer
36 views

Satellites to retrieve UV bands

I want to retrieve some satellite images with UV bands,Bun I don't know which satellites are providing UV bands and We can freely download them? I have already downloaded Modis and Landsat images,But ...
1
vote
1answer
31 views

Is TOA reflectance in floating point or DN? [closed]

After converting at radiance to TOA reflectance,is going to be in DN or floating point.
0
votes
2answers
21 views

How to load two images in ENVI 5.1?

I am using ENVI 5.1 and when I use the Data Manager to load several images and if I want to load two adjacent images, why would one of them load and the other doesn't?. Am I missing something here ?
2
votes
2answers
164 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 ...
4
votes
1answer
1k views

Open Source Alternatives to ERDAS IMAGINE ATCOR?

I have been using ERDAS IMAGINE's ATCOR extension for ATmospheric CORrection of ASTER imagery. What opensource options exist for atmospheric correction of ASTER Level 1B products? I'm primarily ...
2
votes
2answers
45 views

What reflectance curve

I was wondering to what surface that reflectance curve belongs. It is definetely no water or snow since their reflectance drops at a much smaller wavelength. I was thinking about a dense cloud but the ...
1
vote
0answers
29 views

TIMESAT Land cover class

Is it possible to monitor phenology of only 2 land cover classes in TIMESAT? Example is corn and wheat for 7 years. Sowing structure of this crops changes every year, i.e. their location on an image ...