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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4
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1answer
191 views

Methods of cloud shadow detection for Landsat data?

Detecting clouds doesn't seem to be much of a problem, rather the challenge is in selecting cloud-shadow classes that don't also include coastal areas, agriculture, etc. For a project I'm working on, ...
3
votes
1answer
51 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?
3
votes
1answer
40 views

ICESat/GLAS coordinate system conversion

I have to import ICESat GLAS14 product data into ArcGIS. I managed to export into an ASCII file the binary GLAS data using NGAT tool, but the coordinates system are in an uncommon format ...
3
votes
1answer
69 views

Map accuracy assessment by moving window in R

I would like to make an accuracy assessment using a confusion matrix between classified Landsat image and reference dataset. Maps have the same resolution and extent. I would like to evaluate the ...
3
votes
1answer
120 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 ...
3
votes
1answer
56 views

How can I display GeoEye1 imagery in colour in Opticks?

Anyone familiar with the use of the open-source remote sensing software Opticks? Im new to opticks, I load GeoEye1 imagery but it displayed as greyscale. It supposed to be displayed as bands ...
2
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1answer
33 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 ...
2
votes
1answer
227 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
1answer
27 views

how to perform PCA with 2 different landsat scene

I want to perform PCA on 2 sheets of Landsat imagery with different acquisition time and coordinates. prior to processing, should I combine both into one scene (mosaicking process)? if so, how is the ...
3
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0answers
28 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
0answers
39 views

How to detect temporal changes using ArcGIS?

I want to show urban sprawl in a city over ten year period. I took a MOOC on geospatial revolution, therein a link was shared to do such analysis. I just want to show the urban sprawl, nothing ...
3
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0answers
42 views

Multispectral image segmentation for natural-resources applications using R

R has the capacity for image segmentation, although all of the examples I have come across utilize a single band for the segmentation (example). I am interested in combining R's capacity for random ...
3
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0answers
58 views

Thermal Map Data

I am curious about making a thermal map to display where the hot spots and where the cool spots in a community are. Obviously the roads will be hot and the shaded areas with trees will be cool but ...
3
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0answers
88 views

Using Quickbird to discriminate vegetation response and spectral signatures - which season?

I have a study area in N. Florida loblolly pine plantation with 3 treatments (drought, fertilization, drought+fertilization, control) and 4 replicate plots. All plots will be in the same scene. These ...
3
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0answers
165 views

How to merge SeaWiFS and MODIS data or use other merged products?

I hope to produce a time-series for sea surface temperature (SST) and chlorophyll-a (Chl-a) for use in MaxEnt without the use of arcgis, preferring Python tools to others. I am new to satellite data ...
2
votes
0answers
29 views

How to generalize training data for a random forest classifier?

I am working with a random forest classifier in eCognition (new with eCognition 9.0). The image shows 8 NAIP tiles I am attempting to classify using approximately 100 training points. The training ...
2
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0answers
13 views

ASTER mineral indices with VINR and SWIR data

I need to run a supervised classification on ASTER data in order to map a rock formation, which is composed of chert. There is no shortage of indices which can be used to highlight silica rich ...
2
votes
0answers
67 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). ...
2
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0answers
43 views

R: Can raster predict function pass to predict.rfsrc (a prediction function in a parallel verion of RandomForest)?

It seems that raster predict function can pass to predict.randomForest by setting the "type='response'". I am using a parallel version of randomForest package called the "randomForestSRC" and I am ...
2
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0answers
42 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 ...
2
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0answers
37 views

differentiating stone houses from barren rock in ArcGIS 9.3

I'm working in ArcGIS 9.3 trying to differentiate stone houses (often red brick roofs) from barren rock in a typical Mediterranean karst region via remote sensing. I have been using Landsat imagery. I ...
2
votes
0answers
36 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 ...
2
votes
0answers
140 views

ENVISAT ASAR .N1 file is not being opened by ERDAS IMAGINE 2011

I am not able to open ENVISAT ASAR .N1 file in ERDAS IMAGINE 2011. The software has direct read option for files of this format. Whenever I try to open the file, software closes automatically giving ...
2
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0answers
354 views

Principal Component Analysis in QGIS

How do I go about to perform a band ratio and Principal Component analysis in QGIS? I need to derive principal components from ratios of landsat TM bands .
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0answers
7 views

Maintaining spatial integrity of Matlab matrix with missing data

I am working with MODIS Terra imagery (MOD13Q1). I am currently trying to compute the autocorrelation structure of the pixels in an MODIS NDVI raster. The problem is that I have clipped the original ...
1
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0answers
35 views

Batch GDAL_Calc multiple band calculation

I have a question concerning gdal_calc. I´m running windows 7 64b and am working from the OSGeo4W shell. I have multispectral images that need to be prepared for analysis but they are not saved in a ...
1
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0answers
30 views

Urban Heat Island USING ENVI

I have downloaded MODIS images for a specified area.. Its my first time that I am working on UHI (Urban Heat Island).. I need to know the methods to work on it.. I am using ENVI for this.
1
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0answers
78 views

Calculating TOA reflectance from Radiance using Erdas Imagine for a Spot2 image

Using the SPOT equation ρ = π L/[E cos (θs) d-²] to calculate TOA reflectance from Radiance. L was calculated using this equation [L = (X/A) + B] d was calculated by converting date to julian day ...
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0answers
22 views

How to create Strips with GCP point distribution for raw GeoEye satellite imagery?

I have raw GeoEye satellite imagery, I just want some guidelines for creating a strip map with GCP distribution. We need to make orthorectification for raw GeoEye satellite imagery, I think it's ...
1
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0answers
25 views

Water grey levels - remote sensing

by viewing two bands in erdas imagine the grey levels of the water differ. on the one image as below the water is dark and the other image the water is light. why is that? what cause the ...
1
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0answers
21 views

Determine sun elevation without header file?

I have some AWiFS and LISS-III data that I'm trying to convert from at-sensor spectral radiance to top-of-atmosphere reflectance. The problem is, the data didn't come with any header file. All I ...
1
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0answers
116 views

problem of using TIMESAT to processing MODIS NDVI

I want to use TIMESAT software to analyse time series MODIS NDVI data. Firstly, I use MRT tool to mosaic,subset and project MODIS NDVI data and output data as GEOTIFF format, and save as ENVI standard ...
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0answers
52 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 ...
1
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0answers
52 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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0answers
45 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, ...
1
vote
0answers
66 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 ...
1
vote
0answers
142 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 ...
1
vote
0answers
258 views

Question related with NDVI value on water

There is a surreal thing on my NDVI images. NDVI values on lake is ranging from -0.04 to 0.7. (The lake surrounded by forest and has freshwater). Theoretically, negative value of NDVI is correspond to ...
1
vote
0answers
98 views

How to convert MODIS (Vegetation Continuous Fields - MOD44B) to (.img and hdr) in ENVI

Please can anyone help me to convert MODIS (Vegetation Continuous Fields) to (.img and hdr) formats? In ENVI, anytime i try using the MODIS conversion toolkit, a dialog box appears telling me to ...
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0answers
179 views

How to mask clouds in ER Mapper?

I am using ER Mapper. But, I'm still confused how to detect and mask the clouds. I want to reduce or eliminate the cloud to perform supervised and unsupervised classification.
1
vote
0answers
165 views

Averaging satellite data with missing values (using Python)

I am using sea surface temperature, chlorophyll, and other data parameters as covariants in a model, and I would like to average them over a particular time period. I am currently doing this using a ...
0
votes
0answers
15 views

Urban heat island

Since there are lots of products in MODIs for Urban heat Island can anyone suggest me which is the best one?and why?I need to start working on Urban heat Island of some city in Asia but before that I ...
0
votes
0answers
15 views

How to compile the source code of module MOD14 of NASA

I'm working in a project which uses an Active Fire Detection base on MODIS (MOD14) of NASA. The source code and compiled-file can be downloaded at NASA Now I want to compile the source code, ...
0
votes
0answers
40 views

NDVI from QGIS is giving me NaN values

NDVI,TTVI maps are nan values. when I do the NDVI calculation using the raster calculator it looks fine. what's going on?
0
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0answers
50 views

Opticks 4.11.0 (Ubuntu 64bit) - unable to load TIFF file

I am trying Opticks 4.11.0-1 - have official release opticks_4.11.0-1_amd64.deb but unlike in Windows I am totally unable to load Landsat 7 TIFF files. In Windows I can do this using auto importer. In ...
0
votes
0answers
51 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 ...
0
votes
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) ...
0
votes
0answers
227 views

Top-of-atmosphere reflectance conversion with WorldView-2 images

I recently received a set of radiometrically-corrected dynamic range adjusted 8-byte WorldView-2 images. I want to convert to top-of-atmosphere reflectance and would like to use the FLAASH in ENVI 4.8 ...
0
votes
0answers
180 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 ...
0
votes
0answers
44 views

patch analysis and spatial statistics for Grid data

I have TerraSAR data (raster data) for settlement, I must show the large density building, medium and low density in the map. Is this possible in the spatial analysis or patch analysis? I look ...