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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41 views

How to set background value as transparent in ENVI 5

How might I set the nodata/background value as transparent in ENVI 5.0? I know that I can edit the header of the file and set the "ignore value" field, which I tried (setting the field to ...
1
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1answer
31 views

Satellite data to watch atmosphere and ionosphere

Which bandwidths are best suited to watch atmosphere and ionosphere of a region? And what are the sources (satellite sensors/names etc)? Any suggestion would definitely help me to narrow down my ...
2
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2answers
49 views

Pansharpening influence on analysis

Using as an example Landsat 8 bands: Does pansharpening band enhace only visible range and therefore can I use it only for analysis connected with visible spectrum? Or I can pansharpen every possible ...
4
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0answers
37 views

Ice type differentiation using satellite data

I would like to classify glacial area by categories of snow (if there is) and ice, but what's most important: between old ice and fresh ice. They have different properties that are possible to ...
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3answers
193 views

Classifying individual trees from labelled LiDAR point cloud [duplicate]

I have a classified point cloud for an area of 250*250 square meter, with 1 meter resolution. It has a 5 lakhs points with an average point density of 9 (means around 9 points within a pixel). I ...
2
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1answer
41 views

LANDSAT 8 Resolution too low for coastline difference measurement?

I recently extracted coastlines (for my master thesis) for a Bangladesh region for the years 2013 and 2014. Regardless of the method I used, the distance between the 2 coastlines was always the same: ...
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0answers
8 views

How to correct for the shift in AVHRR data?

I just started using the AVHRR 1km global dataset (http://edc2.usgs.gov/1km/1kmhomepage.php) because of a need to examine the long-term forest disturbance history. After acquiring the imagery, I ...
4
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1answer
25 views

Defining city name by using KMZ files

We have KMZ files of different satellite images. We want to check which cities these satellite images belong to. Is there a way to do it automaticly? Like a tool in ArcGIS or QGIS or whatever?
6
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1answer
94 views

Difference between Landsat 7 and Landsat 8 TOA reflectance computation

In section 3.1 of this article it is explained how the Top of Atmosphere Reflectance for Landsat 7 and Landsat 8 are computed. The equation for Landsat 8 is not mentioned explicitly, but can be found ...
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2answers
42 views

Modis MOD11A1 band math expression

I am trying to calculate the temperature of MOD11A1 and I can't find the expression of band math. How the expression temp < 273 could be written at band math?
3
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1answer
37 views

Reflectance values from WorldView-1 images?

Most of the informations on WorldView images are related to the second and third version of the satellite. I own a WorldView-1 image (the black and white one) and I really need to find the reflectance ...
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0answers
46 views

Why are Landsat-8 derived NDVI values higher than SAVI values?

I have calculated NDVI and SAVI vegetation indices for a landsat-8 image. I am unexpectedly getting higher values for the NDVI than SAVI. What may be causing these unusual results? NDVI=0.46 ...
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1answer
56 views

Point otbApplication for python to the relevant OTB DLL's

I installed the latest OTB and Monteverdi on a Win 7 machine. Via osgeo4w I downloaded otbApplication for python, without any dependencies. Python, gdal, numpy scipy and so forth was custom build ...
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0answers
36 views

Using MODTRAN 5?

I am trying to use MODTRAN 5 for atmospheric correction as well as retrieving atmospheric transmittance. Could anyone please help me with the basic MODTRAN 5? There's no video tutorial/guideline on ...
2
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1answer
37 views

Georeferencing an oblique angle photograph in repeat-photograph studies

Backround: Aerial photography and remote sensing can be used to measure current land cover and recent land use change. However, these technologies are fairly recent and therefore time series are ...
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0answers
41 views

How to calculate vertical exaggeration in stereoscopy?

How can I calculate the 'seen' vertical exaggeration of my set of orthophotos, when working with a stereoscope? What factors determine it?
2
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2answers
109 views

How to calculate LAI (Leaf Area Index) using Remote Sensing? [closed]

I am new in remote sensing, and I would like to ask the community what are some good methods to calculate the Leaf Area Index (LAI) using Remote Sensing Data, for agriculture mostly applications.
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0answers
23 views

How to extract coherence and covariance matrices of TerraSAR-X data?

I have obtained quad-polarized level 1b TerraSAR-X data from DLR. When I tried to read the data using PolSARpro, I understood that it is only capable of reading SSC format But my data is in MGD ...
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0answers
23 views

How can I find pixel spacing in azimuth and range and look angle from envi sarscape?

I have a quad-pol ALOS-PALSAR dataset, which I have read using Envi SarScape. Now I find to read the header or where the following information is written: pixel spacing azimuth pixel spacing slant ...
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0answers
22 views

How to make LISS-III image coloured

In order to study land use and land cover change from LISS-III images I want to see the image coloured (i.e. false-colour composite RGB) using ENVI 5.0. What is the procedure?
4
votes
1answer
77 views

Pan sharpening of SPOT and Landsat images

Is there a way I can pansharpen SPOT and Landsat images? I have Panchromatic bands from QuickBird and WordlView-2 images and would want to pansharpen Landsat and SPOT, while still retaining features ...
2
votes
1answer
156 views

Creating composite band mosaic of sentinel 2 data with arcpy

I previously useda simple script that went through many Landsat satellite images, and for each folder it found it made a composite band raster. The script was as follows: import arcpy import os ...
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0answers
20 views

Pre-processing in remote sensing [duplicate]

I have a bit of confusion on the pre-processing of remote sensed images. Do atmospheric correction methods such as Dark Object Subtraction convert the DN into reflectance values? If not, it is ...
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0answers
70 views

Maximum Likelihood Classification in ENVI

I am a new ENVI user and I am trying to perform a supervised classification of a Landsat 8 image with the maximum likelihood algorithm. In order to run the classification, I have to insert a Scale ...
1
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1answer
38 views

How to define a threshold in Principal Component Image for Urban mapping?

I am working on an Urban mapping and i would like to know how i could define a threshold value for extracting built-up areas from a PC (Principal Component) Image ? I am interesting on how to ...
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0answers
54 views

salt marsh recession mapping with landsat/WV, IKONOS) [closed]

I am trying to detect timing and pattern of change in a particular salt marsh (low marsh sitting close to a high marsh). Basically, I'm interested in detecting changes in the leading edge for ...
0
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1answer
41 views

Provider of hyperspectral imagery SWIR band

I'm looking for aerial hyperspectral imaging with SWIR band; size of ground pixel should not exceed 5m and dated not earlier as 2015. Could you propose provider such of data ? Area of interest is ...
2
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1answer
86 views

Sentinel 2 Tool Box on Commandline

Has anyone tried to use the Sentinel toolbox in command-line? I have downloaded the SNAP tool and installed on a Ubuntu workstation and the GUI works well. I now want to want to use it in a ...
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1answer
79 views

Estimation of Land Surface Temperature using ENVI 5.2

I am doing research about land surface temperature using Landsat 8 image. However, I have a problem with them. I have read literature but i can not do it in ENVI 5.2. Could you help me ...
2
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1answer
35 views

Getting exact maximum daily temperature using remote sensing?

I have a problem I want to find the land surface temperature of Bangkok using landsat8. I have everything to get it but the problem is landsat images are obtained during morning time but the maximum ...
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0answers
25 views

About land surface temperature?

I have a problem I want to find the land surface temperature of Bangkok using landsat8. I have everything to get it but the problem is landsat images are obtained during morning time but the maximum ...
0
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0answers
10 views

Mosaic georef is a few pixels off for half of my image, how to georeference?

I have two sat. images from the same platform on two different dates. The images overlap each other nicely, but I cant get them to accurately mosaic into one raster image. I merged the two photos ...
3
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2answers
618 views

Opening image files with Sentinel 2 toolbox

Anyone worked with the Sentinel-2 toolbox/SNAP? It doesn't support sentine-2 data to be opened directly. I tried opening .safe, .zip and .xml files.
1
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1answer
38 views

Adding Subdatasets in ArcMap

I have some MODIS imagery that I want to display in true colour, however when I add the data it gives me 13 subdatsets to choose from. I've never worked with this before and I'm not sure which ...
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0answers
31 views

Difference between radiometric correction at surface and at sensor in ENVI

I want to ask you about the difference between the radiometric correction at surface and at sensor in ENVI software, I do the two in flash and radiometric correction and the results was same image. ...
3
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0answers
69 views

Using original Landsat multispectral image or pan-sharpened image in land cover classification?

I am currently creating land cover maps of a number of national parks across Asia from Landsat 8 imagery and also later from SPOT imagery. I plan to use supervised classifications in ERDAS IMAGINE and ...
5
votes
3answers
186 views

Differentiating bare soil and urban areas in Landsat 4-5 land cover classification?

I am trying to classify a Landsat 4-5 image using the semi automatic classification plugin (QGIS). I always get misclassifications between bare soil and urban areas as they have similar spectral ...
0
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1answer
109 views

Land Surface Temperature

Estimation of Land Surface Temperature Contact measurements of emissivity values of the surfaces using thermal radiometers and spectral assessment of samples supplementedLST estimation ...
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1answer
81 views

Where can I find SRTM DSMs (digital surface model)?

I'm interested in finding a 30 meter DSM (digital surface model that includes canopy) from SRTM with the hope of creating a 30 meter canopy height model. I know that it can be done because the ...
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1answer
40 views

About PolSDP software for SAR processing [closed]

Can anybody help me to find PolSDP software or provide a link from where I can download.
4
votes
2answers
79 views

Accessing the Quality Band for MCD12Q1 with MODISTools GetBands

I am using MODISTools (https://github.com/seantuck12/MODISTools) to process MCD12Q1 data, which, according to the LP DAAC website ...
3
votes
2answers
77 views

Difference between Ground Sampling Distance and pixel size in RapidEye

I am a bit confused about reading technical specifications on RapidEye satellites. I assumed that Ground sampling distance (GSD) and pixel size express the same meaning, while GSD is 6.5 m, and pixel ...
0
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2answers
60 views

Which one is best for atmospheric correction?

My aim is to determine surface temperature extraction by computing NDVI from Landsat 7 and Landsat 8. suggest me which method DOS (dark object subtraction) or FLAASH atmospheric correction in ENVI ...
1
vote
1answer
67 views

How to determine the bands from an aerial image?

I received a set of aerial images taken with a Canon camera, I don´t know which kind of lens it has, or if it has been modified. After performing split image algorithm in Qgis, I get four new files: ...
9
votes
2answers
164 views

How precise are overpass times of sun-synchronous satellites?

sun-synchronous satellites, as their name say, acquire scenes at the same solar time of the day when they pass over the same location. According to this site, sun-synchronicity is achieved by taking ...
7
votes
2answers
187 views

Are PDAL or PCL capable of producing LiDAR grid metrics?

I typically use Windows-based FUSION to generate grid metrics, which can be used to describe forest structural characteristics. From the FUSION documentation: GridMetrics computes a series of ...
2
votes
1answer
123 views

Existence of fiducials marks in a digital camera file

Existence of fiducials marks in a digital camera file I have created a generic digital camera file using Erdas 2015 with the following data in it: LPS Camera File Version: 2.0 Camera Name: "generic ...
4
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0answers
103 views

Counting number of plants in area using images from UAV?

How do I count the number of pineapple plants in a 1-hectare block? I have heard of these algorithms but I don't know how to do it. I'm still a newbie of QGIS, ArcGIS and ENVI. I have the NIR, RGB, ...
3
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2answers
314 views

Classify forest with NDVI from Landsat 8 and 7

I'd like to calculate the NDVI for multi-date satellite images of Landsat (7,8) to perform a change detection on the deforestation of the Amazon rainforest. I already acquired surface reflectance ...
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0answers
63 views

How to mosaic multiple MODIS images of Multiple months using MRT tool?

I have monthly MODIS images for 2001-2014. For few images mosaicing with reprojection can be done using MRT tool. However, for large number of images it's a cumbersome process. There are multiple ...