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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0answers
10 views

Landsat 5TM pre-processing - histogram matching

I'm totally new user of GRASS and of course I have some problems. I want to do the pre-processing of Landsat (5TM) images (for further band composite, classification and NDVI) and I was using the tips ...
1
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0answers
8 views

Extract Differential Interferometry from SENTINEL-1 image

I downloaded some SLC images from scihub.esa.int . And I want to extract Differencial Interferometry from them by using SNAP-ESA software ( if you have other softwares that can do the same work I ...
1
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1answer
21 views

Doing NDVI when nir data is given as 3 bands

I have been provided with two data sets of the same area, one with normal RGB bands and one with NIR data. My problem is that since the NIR data is given as 3 bands, i am not sure how I should ...
1
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0answers
12 views

Modis Daily LST Data is mean of all day or it is on satellite path time?

I am looking for MODIS LST product which is exactly on the same time that satellite paths from a location,I have searched and found MOD11A1 but It seems that it is mean LST of Day,Is there any product ...
2
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1answer
52 views

How can I parse modis MOD13Q1 quality layers in R?

I'd like to parse MOD13Q1 VI quality layers in R -- the code I have so far must be incorrect, because I'm seeing lots of "deep ocean" flags in the middle of Brazil: library(raster) library(rgdal) ## ...
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1answer
24 views

Need to develop a model for measuring inter-annual and seasonal variability in pasture cover using modis 16 day composites

Aiming to use statistical methods in ArcGis and Envi image analysis to measure inter-annual and seasonal variability in paster cover using MODIS 16 day composite image from 2000-2014. Quite stuck on ...
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0answers
19 views

Layer Stacking landsat 5 surface reflectance high level data

I downloaded the surface reflectance landsat 5 scenes but when I layer stacked them my image was not how I imagined. I manually used atcor on normal scenes and it looks nothing like the scenes I layer ...
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0answers
38 views

Difference map in QGIS

I have remote sensed areas of certain vegetation (of 3 different years) and produced polygon shapefiles representing those. Now I wish to show the areas between say two year (shrinking or expanding of ...
2
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1answer
40 views

Using Erdas for land cover land use change detection

New to Erdas but I have to do a project and I have chosen to do a landcover land change detection. I have two Landsat 5 images, five years apart from each other. My question is: what is my next step? ...
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0answers
47 views

Error in downloading MODIS image using R script

I am trying to download "MOD13A3" MODIS image using R script (http://r-gis.net/?q=ModisDownload) but each time it's ending in error. How to make it work ? ...
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1answer
53 views

Accuracy assessment in eCognition

How to do accuracy assessment of classified images in ecognition? I have done the image segmentation for Worldview-2 image. Then, I have processed for classification for class names (e.g ...
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1answer
16 views

Adding GeoEye1 sensor to grass i.atcorr

Following the instructions, I've updated the iwave.h and iwave.cpp files using the official spectral responses from DigitalGlobe (In the iwave.h file I don't know if it's necessary to use more ...
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0answers
27 views

IR/R could not detect when using landsat 8 in ERDAS 2014 Is there a alternative way around?

I'm using ERDAS 2014 and I upgraded from ERDAS 2013. I am doing a lot of band indices for various kinds of such as clay, ferrous, Mineral composite and so on.. from landsat 8. Using the indices in ...
7
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1answer
287 views

Remote sensing for Nepal Earthquake [closed]

To any experts who can provide remote sensing data that can help assess impact and damage of nepal earthquake we really need your help to ensure aid is well targeted. Existing data so far is here If ...
3
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1answer
519 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 ...
0
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1answer
8 views

Finding Sentinel-1 data from the hub

Can somebody please tell me how to download data from specific locations on the sentinel-1 data hub? I cannot seem to get the geospatial search function to work... Many thanks for guidance!
3
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1answer
232 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 ...
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0answers
27 views

Classifying beach/mudflat area of Landsat Images

For my work I need to capture the total catchment area of a beach using mostly Google Earth images. I attached an example with this post. So the whole catchment area comprises the sandy beach as well ...
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1answer
16 views

How to convert an endmember collection spectral signature file from OLI sensor to TM and ETM+ sensors

I'm working on some supervised classifications using scenes from the landsat legacy archive wich include ETM+, TM 5 and OLI data from 2001 to 2014. I have training and validation points for each scene ...
6
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2answers
186 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 ...
0
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1answer
20 views

NDVI for natural region

I have a question about remote sensing, I appreciate that if somebody can answer to me. I have remote sensing data which I have got from landsat 7. The area which I am working on is combination of ...
9
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2answers
906 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. ...
4
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3answers
100 views

Estimating vegetation composition from digital images

I am running a Master's project researching Greater prairie-chicken nest and brood survival. Some of my intended covariates include local vegetation measures using digital imagery. I would like to use ...
5
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2answers
498 views

What are LiDAR returns?

Can someone help with an explanation and some references, in order to understand the nature of return pulses within a LiDAR system.
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0answers
27 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
11 views

How to classify land cover with MMU 25hac

By using the 30 meter resolution of landsat TM & ETM+ data, I want to create the land use/ land cover map. I have read in several studies to first decide about the minimum mapping unit (MMU) that ...
0
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1answer
215 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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1answer
32 views

How to remove band from stack in ERDAS 2013?

I have a Landsat 8 scene where I have stacked 11 bands. I need to remove one band from the stacked layer. Is there a toolbox in ERDAS 2013 that allows me to take out a band? I am aware that ENVI ...
21
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6answers
3k views

Is GPS more accurate on specific hours of the day?

I have heard that the GPS system is more accurate, and less accurate on some specific hours on the day. If this is true, how can I get the information on when GPS is more or less accurate at my ...
1
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1answer
39 views

Python/GDAL hyperspectral Image wavelengths

I can open and read a hyperspectral image using GDAL according to the instructions brought by Max König here: So after reading the data like this : data = gdal.Open( filename ) then I can see ...
0
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0answers
21 views

When parametric classifiers fail?

In which situations are statistical assumptions (e.g. multivariate normal distribution within spectral classes) for parametric classifiers (e.g. maximum likelihood ) not valid for land-cover ...
3
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2answers
363 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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0answers
42 views

Landsat 7 band 6 VCID 1 (LOW) or VCID 2 (HIGH) for temperature map?

I want create water temperature map with Landsat 7 on QGIS. Band 6 converting to temperature, I read the landsat handbook with formula: T= K2/ (ln((K1/L)-1)). Band 6 has VCID1 "low" and VCID2 "high" - ...
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2answers
42 views

Where to download 4-band NAIP imagery for California?

I've been trying to find orthoimages with 4 bands for a couple of counties in California. I managed to download some from the GeoSpatial Data Gateway from the USDA (NRCS), but they all only have 3 ...
2
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3answers
2k views

Where to download 4 band NAIP imagery?

I seem to recall USGS Earthexplorer providing current and historic 4 band NAIP imagery over the last few years. It appears that these data have been migrated to the National Map. However, the ...
3
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1answer
58 views

Calculate change in canopy height over 10 years?

I want to know how many "tall" trees (greater than 30 m) fell down between 2005 and 2015. I have LIDAR imagery from 2005 and 2015 from an area where many tall trees are known to have fallen due to ...
1
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1answer
39 views

How to create an image of maximum pixel values from an input layer-stack image in ERDAS Imagine?

I have 12 MODIS images (one of each month). I want to create a single image having maximum annual pixel values for each pixel. I did layer stacking operation in Erdas Imagine 13, but how to extract ...
3
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3answers
458 views

Tasseled Cap Transformation Rapid Eye

I want to do tasseled cap transformation on rapid eye data. the main question would be about the parameters which are used. Somebody has a suggestion?
4
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3answers
135 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.
9
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5answers
6k views

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 ...
2
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1answer
40 views

View feature space for multi-band files

I am trying to plot a feature space (scatter plot) for some SPOT images in QGIS 2.8.1. I know a histogram is available in the file properties, but I want to plot eg. Band 1 vs Band 2 to see the ...
0
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2answers
61 views

AVHRR Max NDVI product

I'm trying to take a max annual NDVI product derived from AVHRR and relate it to a specific area that I'm examining.This requires me to identify the region of interest based on Landsat scenes, and ...
1
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1answer
32 views

how to generate metadata file for semi automatic classification plug in?

I am working on satellite images. The region I am interested in is only a fraction of the whole satellite images. My laptop slows down tremendously when working on the whole image. So I clipped the ...
0
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1answer
31 views

True color combination using Resourcesat-1?

I am working with an image from India. According to the metadata, I am working with an image acquired by the AWiFS sensor from Resourcesat-1: ...
1
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2answers
60 views

How to destripe the thermal band in SLC_off LandSat 7 ETM+ data?

I am working on a special study in one of my subject. My study would require me to extract land surface temperature each year for 2007-2014. Since LandSat 5 ceaseed to operate last 2011, my 2012-2014 ...
0
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1answer
154 views

Empty raster returned after GRASS i.atcorr with Landsat8 data

I've searched at length on previous forums but no solution seems to work for me. I'm trying to run the i.atcorr module on GRASS (version 6.4.3 on a Macbook Pro, Mavericks OSX) with Landsat8 imagery. ...
1
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2answers
179 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 ...
1
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1answer
22 views

MODIS MOD10A2 snow product

I have extracted pixel value ( pixel value=200 for snow) from MOD10A2 snow product for my study area. Since MOD10A2 product is distributed every 8-days. i.e., 9th Jan, 17th Jan, 25th Jan,2nd Feb,.... ...
1
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1answer
210 views

QUAC atmospheric correction for Landsat-8 (ENVI 5.0)

I try to realize QUAC atmospheric correction for the band 4 and band 5 of Landsat-8 in ENVI5.0. This version doesn’t support Landsat8 (doesn’t have parameters of Landsat-8). At the first step I glued ...
0
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1answer
50 views

atmospheric correction in ENVI 5.1

I want to perform atmospheric correction on Landsat 8 images in ENVI 5.1. In order to create radiance image, I selected basic tools> preprocessing> calibration utilities> Landsat calibration. However, ...