Tagged Questions

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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1
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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
vote
2answers
168 views

Missing Dependency in SAGA. Orfeo Toolbox does not work

Hej guys, I am trying to perforem segmentation from Orfeo Toolbox (QGIS last version 2.2), whenever I try to use the toolbox, I get the following message: Oooops! The following output layers could ...
1
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2answers
120 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. ...
2
votes
1answer
285 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 ...
-2
votes
1answer
93 views

MODIS LST 8 days data to have 16 days LST? [closed]

can i combinate two parameters with different Temporal Granularity , i mean can i combinate image LST MODIS 8 days with image NDVI modis 16 days??
0
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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
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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
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2answers
516 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 ...
0
votes
1answer
165 views

What software programs can run a supervised classification on an image segmented into objects?

I am trying to run a supervised MLC classification on a multispectral remotely sensed image, however, I want the image to be classified using a shapefile of segmented image objects (as opposed to the ...
2
votes
2answers
367 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
vote
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 ...
2
votes
0answers
38 views

“Back calculating” to quantify the “atmospheric effect” of water vapor or other gases in a “corrected” hyperspectral image using QUAC?

I know that when using FLAASH in ENVI, you can produce a water vapor map (caveats considered) from your atmospheric correction. My question is if it is possible to "back-calculate" a water vapor map ...
0
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0answers
59 views

Masked data included in ISODATA classification computations?

I am using ENVI to mask NDVI MOD13Q1 images using the "pixel_reliability" raster included in the MOD13Q1 hdf. All instances of cloud cover (pixel_reliability=3) have been masked (=0). I have applied ...
3
votes
1answer
136 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 ...
0
votes
1answer
62 views

Load a .sav file in ENVI

I have a 23-band .sav file that I need to load in ENVI. The 23 bands are 23 time points of MODIS NDVI data. I ultimately want to run a classification on this data. I have been using Data Manager to ...
1
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0answers
50 views

Distinguish between the types of cultivated crops in remote sensing

I recently produced map of LULC but there is the difficulty of distinguishing between the types of crops. Is there a method to distinguish between the types of cultivated crops such as wheat, barley, ...
9
votes
5answers
1k views

Recommended programming language for remote sensing?

I am beginning studies that hopefully will lead to a long career as a remote sensing specialist. I am currently working with ArcGIS for some applications and learning ENVI for others. I have ...
0
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0answers
49 views

MODIS L1B to Reflectance

Could we convert MODIS L1B to reflectance data rather than using data product MOD09 (7 bands)? If can, may I know how to convert it? Is there any source, published paper, forums, or any modeler (.gmd) ...
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 ...
1
vote
1answer
684 views

Help with gap mask filling and landsat 7 in arcgis 10

i have downloaded images from Landsat 7 ETM+ SLC-off with corresponding gap mask. which is the best method for using it with arcgis 10, i tried the mask and statistical method described in arcgishelp ...
1
vote
1answer
595 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 ...
0
votes
1answer
427 views

EVI and SAVI indices for Landsat 7 and Landsat 8

I'm trying to run the indices Savi and EVI at landsat 7 & 8. About SAVI I read this from ESRI and explains very good this index. About SAVI I have a question, I will choose buy my self the L ...
1
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0answers
77 views

Importing GPS coordinates to extract multiple DN values in ERDAS

I have a set of GPS points (stored as a csv for now) and would like to import these points to ERDAS to find the DN values associated with each location. I am able to import a SHP to ERDAS but the ...
3
votes
1answer
100 views

Calculate ground nadir line from PV coordinates

I'm using an API which returns a satellite's PVCoordinates (Position/Velocity pairs). {P(1036869.5330731269, 6546536.584960848, 9.892293545390519E-11), V(-9994.355195123433, 1582.9503539842497, ...
3
votes
1answer
214 views

Create DEM from cartosat stereo pairs?

I have two carstosat stereo pair images. All i need to do is to extract DEM from those. So, i tried it doing with OSGeo4W. but i didn't succeeded in it. So IS there any other softwares or opensource ...
2
votes
0answers
48 views

Is there any statistical method to proof if the method is suitable or not [closed]

I have recently done a phenological study using threshold method from MODIS NDVI images. But I'm suffered that I don't have any situ observation (ground truth) data to do validation. Is there any ...
3
votes
4answers
267 views

Some remote sensing tutorials [closed]

I could use some tutorials on remote sensing, but some books provided they are free, would be useful. To be specific, tutorials on ERDAS Imagine, ENVI and other remote sensing software, general ...
4
votes
4answers
928 views

Alternatives for ERDAS Imagine

I am having trouble with the ArcGIS 10.1 and ERDAS Imagine 9.2 license conflict. From what I found out it isn't that rare, but interestingly enough why is there such a conflict in the first place? ...
3
votes
1answer
355 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
151 views

How to do change detection between two Landsat scenes?

I want to do change detection and calculate the changes step by step using two images: the first image Landsat 1986, and the second Landsat 2000. Actually I have used image differences in ArcMap and ...
3
votes
1answer
52 views

Sample classification datasets?

I was looking for some publicly available ground data classification datasets, specifically, locations in e.g. latitude/longitude with a description of the land cover/land use, and a reference e.g. ...
3
votes
2answers
684 views

Are there Python packages for Landsat 8 processing?

While there are a number of python projects for MODIS acquisition and processing (pyModis and get_modis), I have yet to encounter a toolset for automating Landsat 8 processing in Python. There's ...
2
votes
1answer
53 views

Need information about the Envisat satellite

I am new to remote sensing and I want to know about sensor design of Envisat satellite. Can anybody help me or preferably direct me to some good references?
1
vote
1answer
293 views

How to do geometric correction of remote sensing data in R?

My challenge is to replace most of the remote sensing commercial tools with R code (I'm teaching assistant at the University and I would like to move to open source R code to show the added values to ...
2
votes
1answer
40 views

Question on how many ASTER per year ? per month?

How many scenes are there for ASTER per year ? From what I understand is that the temporal is every 16 days. So, some month it will have 2 and some months it will have one. Thanks.
4
votes
2answers
197 views

Zooming into landsat-8 produces pixellated view

I am working on a project were I am using LANDSAT 8 images for remote sensing. The issue that I have is that when I zoom into them the photo is pixellated. I can not see a thing. When I zoom out ...
15
votes
4answers
574 views

Is there a tool that performs automatic recognition of buildings?

I'm wondering if there is a tool, which takes a satellite map of a region, detects typical buildings and allows the user to review its result (check, whether the tool correctly identified the ...
1
vote
1answer
63 views

Finding Normal to a given point in ECEF coordinates

I have a point of reference called Ground Reference Point (GRP) given in Earth Centred Earth Fixed (ECEF) coordinates as given below: (1.4892e+6, 6.1102e+6, 1.0637e+6) (all distances in meters) I ...
5
votes
1answer
1k views

Atmospheric Corrections for Landsat 8 OLI Using Orfeo Toolbox

I am trying to correct some Landsat 8 OLI imagery using the Orfeo Toolbox Optical Calibration tool via QGIS. I've retrieved data from Aeronet as well as relative spectral response data for the OLI ...
5
votes
3answers
349 views

DEM generation from ASTER L1B imagery using FOSS

Is there any (photogrammetric or other) FOSS package to support the generation of a DEM from ASTER L1B products (i.e. combining the spectral bands 3N and 3B)? Are there any practical examples or/and ...
1
vote
5answers
761 views

Fix Landsat 7 SLC-off in ENVI?

I have a couple of Landsat 7 images and they all have striping as a result of the SLC failure. Does anyone have any suggestions as to how to destripe the image using ENVI? I plan to use these images ...
8
votes
2answers
519 views

How do you explain that band width and relative spectral response of MODIS band do not match?

To define relative spectral response, I referred to EFFECT OF RELATIVE SPECTRAL RESPONSE ON MULTI-SPECTRAL MEASUREMENTS AND NDVI FROM DIFFERENT REMOTE SENSING SYSTEMS by David James Fleming, 2006. ...
0
votes
0answers
199 views

Atmospheric correction for RapideEye without atmospheric parameters

I'd like to perform an atmospheric correction of my RapidEye images but metadata do no include atmospheric parameters required to use the 6s algo implemented in the Orfeo ToolBox. Is there a solution ...
4
votes
2answers
280 views

What does MODIS data reflectance values (MOD13Q1) mean?

Several publications suggest filtering MODIS data (in my case MOD13Q1) prior to use. They recommended to filter out pixels having blue reflectance more than 10%, but what 10% here means? is it 10% of ...
2
votes
1answer
242 views

I need some more information on ASTER for time series analysis

See my previous post on ASTER I have a question about that I am not sure about. So, if I wanted to analyze 10 years or so, do I need to download each ASTER file for each year (e.g. 2003 ASTER, 2004 ...
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votes
2answers
138 views

How to derive soil water holding capacity from Landsat data [closed]

For estimation crop yields, I need some information such as Soil water holding capacity, potential evapotranspiration, crop types of the area, etc. For this purpose, I want to derive Soil Water ...
3
votes
2answers
781 views

Figuring out map scale when you know the spatial resolution of a Satellite Image?

I'm interested in figuring out how map scale and satellite pixel size (spatial resolution) are related. For example the TM or ETM+ has roughly 30m ground resolution, then, what could be the finest ...
1
vote
0answers
146 views

Change Detection ArcGIS with multiple dates

I'll explain my aim first: I am trying to create a single raster to represent vegetation resilience, I am doing this via change detection. So far I have created 5 Change detection images, where 2000 ...
3
votes
0answers
105 views

Counting animals using near infrared imagery from a drone [closed]

I am playing around with an idea of using a near infrared camera to fly transects to count animals on the ground. I have been involved in such work earlier, but on bigger mammals and observer based ...
2
votes
2answers
117 views

How to reduce the resolution of satellite imagery data for use in MATLAB

When I am using the 4-band multispectral data for NDVI calculation, after successful completion of runtime, it shows some warning message like "Loading 17%..." How should I rectify it? Should I do ...