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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2
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1answer
16 views

Why are colour distorted at large solar zenith angle in satellite image?

Most Earth observation satellites consider large Solar Zenith Angle as undesirable are therefore do not process them. There are indeed several known image quality issues, such as low signal (inducing ...
0
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0answers
20 views

Sentinel-1: biomass for agriculture

How do can I calculate biomass for some agriculture by using VV and VH polarisation SAR images? I know there are some correlation for HV RADARSAT-2 to get biomass for some agriculture like corn, wheat,...
0
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1answer
27 views

How to compare EVI values with NDVI values?

I have been doing NDVI (Landsat 4-5) analysis for my research area for some time now. I recently decided to try out EVI (MODIS). But the EVI values I get are a bit different from NDVI. For example ...
0
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2answers
21 views

Source of radar imagery for coastal areas

For my final year research project I need radar images of coastal areas. And can anyone help me to find links where I can download such data free for research purposes?
0
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1answer
16 views

How to remove cloudy pixel from MODIS NDVI (MOD13Q1)

I am using MODIS NDVI product (MOD13Q1) for the vegetation changes study. I want to remove cloudy or bad pixel from MODIS NDVI data. I am not getting any suitable method or software or any program to ...
2
votes
1answer
24 views

EVI coefficient values for Sentinel 2 image analysis

I am estimating EVI for Sentinel imagery and wanted to know the values of the coefficients L, C1, C2 etc. All the literature I have found use values from MODIS.
0
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1answer
15 views

Selecting granule from ASTER Global DEM V2

I am following this tutorial in order to download ASTER Global DEM V2 data: http://www.echo.nasa.gov/reference/reverbastergdem_tutorial.htm on http://reverb.echo.nasa.gov/reverb/ Step 7 is to "Select ...
0
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3answers
78 views

Building python script to compute monthly average from 8 days MODIS data

Goal- Building python script to compute monthly average from 8 days MODIS data I have MODIS data which is contain 8 days product. Some of month has 3 images and some of month has four imgaes. So how ...
0
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0answers
27 views

Is the radiance and reflectance required for landsat 7 and landsat 8 for urban detection

I am working on urban detection in a an area where roads are made by cutting the forest. I want to ask that it is necessary both radiance and reflectance? I am narrowing my question as: I want to do ...
1
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1answer
18 views

How to select a fixed dimension ROI in ENVI?

ENVI provides the freedom to select ROIs by drawing polygons etc. I want to clip a fixed size ROI, say 512 x 512 in size. Is there a way to do that?
-1
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2answers
51 views

What is the index formula to calculate water stress index using multispectral sensor (Red, Blue, Green, Red edge, NIR)?

I am having a multispectral sensor with Red band, Blue band, Green band, Red-edge band and Near-Infrared band. I need to find water stress using these bands, is it possible to find and if yes what ...
0
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0answers
27 views

Visualizing Aura/OMI SO2 data

I am trying to visualize hdf5-files from the OMSO2 data set of NASA so that they will look like this (Orbit 63543 on 25 June 2016, found here and from this website): However, when I try to ...
2
votes
1answer
45 views

Error in lansat 7 image

The actual shape of lake is like in the right corner, but in lansat 7 image that i downloaded a strip is misplaced(left image) or shifted.][how can i correct this, i have tried georeferencing already ...
1
vote
1answer
19 views

How to apply Melt Area Detection Index to MODIS imagery?

I am working with some MODIS imagery for a project (I'm relatively new to remote sensing) using MOD09GA, and hoping to apply a melt area detection index (MADI) to images to calculate melt day length ...
1
vote
1answer
26 views

Bulk Download App 'Insuficient Previledges'

Ordered Landsat 7 data from USGS and wants to download it using the Bulk Download application. However, i get this error while running the software. I have JRE Installed properly. Does someone knows ...
3
votes
1answer
41 views

How to represent seasonal variability in a single global NDVI map?

I have twelve monthly MODIS datasets for a 1 year period (http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MOD13A2_M_NDVI&year=2015) and wish to combine all the data into a single map highlighting ...
0
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0answers
19 views

What units are associated with these raster bands?

The picture is a scatterplot of roughly 400 pixel values from 4 different raster bands. Im curious what the units are? They do not correspond with the sensor's band values. Sensor is WV-II. 1 - Red ...
0
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0answers
17 views

Why Pixel value is zero in Image metada? Do Pixel value and file pixel value represent different or same meaning?

I have opened a Raster Raw image in Erdas Imagine and stacked four bands and I opened the stacked image in software. After I opened the metadata from home menu. I clicked on Pixel and saw that all ...
2
votes
1answer
73 views

KEA File Conversion using gdal_translate

I was using ARCSI (The Atmospheric and Radiometric Correction of Satellite Imagery) to convert a 'kea' file format to 'tif' format using this gdal statement (gdal_translate –of GTIFF LS8_sref.kea ...
3
votes
1answer
86 views

Resolving Sentinel-1 Interferogram Unwrapping error when constructing DEM/DSM?

I have been trying to create a DSM of a coast and some islands, and have run into some issues regarding how the data looks in the unwrapped interferogram (which affects my height data). I have been ...
2
votes
3answers
47 views

substitute for landsat 7 for land classification?

I am doing a project where I need to do a land classification for a forest reserve in Honduras. The dates I need are 2005, 2010, and 2015. I'm good for 2015 with LS8, but I am having difficulty with ...
3
votes
1answer
60 views

Random Forest out of the bag and confusion matrix

I have implemented Random Forest classifier to classify remote sensing data in R. The original code comes from here: How to perform Random Forest land classification? Everything works fine, but what ...
0
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1answer
60 views

How to calculate GSD(ground sample distance) from zoom level and vise versa

I am an application programmer, a beginner in the GIS domain. I have an image with its ground sample distance parameter. I need to associate the zoom level with GSD. I am using MapBox.
2
votes
1answer
38 views

vegetation classification from only the panchromatic band

I am mapping mangroves over a period of several years using satellite imagery. I use QGIS semi automatic classification plug in. Supervised classification (maximum likelihood) as I can visually ...
1
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0answers
19 views

Complex Coherence with SNAP or SarScape

is it possible to estimate the complex coherence between two RADARSAT-2 SLC images with SNAP or SarScape? If I try to estimate the Coherence I get only float data but I need it in a complex form.
0
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1answer
36 views

modis surface reflectance

I wanted to perform atmospheric correction using MODIS surface reflectance products for validating my atmospherically corrected images (from Landsat 8). As Landsat 8 only became available in 2013, is ...
1
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0answers
20 views

Why can't get correct RGB img of Landsat 8 using np.dstack

I use np.dstack to stack Band4, Band3, and Band2 of Landsat8 data to get ture color image,I use code from Milos Miljkovic, but the result looks incorrect. import numpy as np from matplotlib import ...
4
votes
2answers
63 views

Pattern search in satellite imagery

I would like to search for the specific buildings (polyhouse in my case) on the map like the one shown here Are there any free options available which can give me lat and lng of such shapes/...
0
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0answers
26 views

Downloading high resolution multi spectral commercial satellite images

how can i download high resolution multi spectral commercial satellite images like rapid eye, worldview etc. that have less return period like 1,2 or few days .And i need image of Pokhara city of ...
0
votes
1answer
45 views

After doing TOA correction to a lansat 8 image band using raster calculator, the reflectance is slightly out of range. Why is that so?

the reflectance range was like for example 0.0023 to -1.02356 for some band and -0.0156 to 0.009. Why is this reflectance range slightly out of range? Isn't it should be in exactly in between 0 to 1. ...
0
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0answers
42 views

land sat 8 sensor zenith and azimuth angle

i need Landsat 8 sensor zenith and azimuth angle for atmospheric correction using 6S but in "mtl" file only solar zenith and azimuth angle information is given
0
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0answers
44 views

Calculating Excess Green / Excess Red vegetation indices using Adobe CS6

I am undertaking an agricultural mapping project in which I'm imaging a field using a UAV equipped with a 16.1MP RGB digital camera. I am attempting to process the images to yield vegetation indices ...
1
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0answers
51 views

Combining hyperspectral bands to form a multispectral image?

I understand that the difference between the two are the number and width of the bands. Given a hyperspectral image, is it possible to 'convert' it to multispectral ? In this paper for example, the ...
3
votes
1answer
23 views

Except from Hyperion do you know any other hyper-spectral satellites?

There aren't many images for my research area. So I am looking for other hyperspectral satellites. Or maybe another site except USGS? The area is near here "40.223124, 23.031155"
0
votes
2answers
52 views

Landsat 8 Band Value Range

I'm confused as to the range of brightness values associated with Landsat 8 Bands. I know that for Landsat 7 and below it has always been 0 - 255 but some of the literature indicates that Landsat 8 ...
1
vote
1answer
42 views

Hyperspectral Imaging - Material spectral signature

I am reading about the working principles and applications of hyperspectral imaging (HSI). In this link, the uses of HSI over the range of the wavelength, from visible to longwave infrared have been ...
2
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0answers
22 views

Converting CDF file to NetCDF file to use in ArcMap? [duplicate]

This is a GIS question as well as a Remote Sensing question. I have downloaded CDF files from the ESA from MyEarth online and want to use them in ArcMap. In ArcMap you can Make NetCDF a Raster Layer. ...
3
votes
2answers
180 views

Removing cloud from Sentinel 2A imagery?

I would like to use sentinel 2A imagery to look at canopy cover in Northern Vietnam. The only problem is that ALL the recent images have large amounts of cloud in the area I want to look at. Is it ...
1
vote
1answer
61 views

Getting latitude-longitudes from tiff and world file

I have downloaded Version 4 DMSP-OLS from here, which is a bunch of tiff files with their world files. I would now like to crop an area specified by bottom left and top right lat-long points. I ...
1
vote
1answer
38 views

Remove raster pixel in R

This is the 32 year trend NDVI (raster data) I would like to remove the green grids data by using R (the green pixel value is larger than 0.03) and this one is R code that i use but i cannot ...
2
votes
0answers
41 views

Negative reflectance values after topographic corrections (cosine correction and modified Minnaert correction)

I am trying to manually correct the surface reflectance values of some Landsat 7 and 8 images. I'm using Minnaert modified method, which uses the cosine correction as one of its inputs (see below the ...
2
votes
1answer
49 views

MODIS temperature and NDVI data?

hope anyone could give me some hints here. I tried to download free MODIS data from their page(resolution 500m, 1km). Im interested in NDVI and temperature data. But when i load the hdf files into my ...
0
votes
1answer
91 views

How to analyze Vegetation Index using Sentinel-1 SAR Imagery?

I am using the ESA open scientific data hub for Sentinel 1 SAR imagery (Interferometric Wide swath SLC VV polarization) and would like to know how to perform vegetation health analysis from this data? ...
4
votes
1answer
68 views

Detect cattle on high resolution satellite images

I have no deep experience in remote sensing. I would like to know if it might be feasible to detect cattle (i.e. a single cow or bull) from a high resolution satellite image e.g. Worldview 3 with a ...
1
vote
0answers
15 views

What indices could is use for coastline extraction using rapideye imagery

I am currently writing a proposal to get RapidEye imagery for my master thesis. In this proposal I am trying to explain what I am doing. Except NDVI/NDVI-RedEdge and NDWI, can anyone suggest some ...
1
vote
1answer
12 views

MODIS emissivity extraction

I am doing validation of 40 Landsat images.now I need two spectral emissivities of the 8-day MODIS land surface temperature and emissivity product (MOD11A2).and I have to extract emissivities for ...
2
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0answers
38 views

MODIS Imagery Orthorectification (Open Source)

I am looking for an open source free software/tool for orthorectification/Geometric terrain correction of MODIS imagery. I have looked at ESA (European Space Agency) SNAP but this sensor type is not ...
0
votes
1answer
35 views

Methodology for Image Classification (beginner) [closed]

I'm a beginner with remote sensing and have the task of creating a land use/land cover map of a region in India from IRS imagery. I've never performed an image classification before, although I do ...
1
vote
1answer
27 views

Are my reflectance values of bands in range and what does DRA in GIS 10.1 do to bands?

I have done the TOA correction to red and near infrared bands using raster calculator and calculated NDVI from lansat 8 image. The NDVI range came as : upper range=184 and lower range=(-235). When I ...
0
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0answers
30 views

Free satellite images for academic purposes [duplicate]

Since the Landsat mission opened it's archive a lot of great scientific studies have been produced in the field of Remote Sensing. The Sentinel imagery from ESA is also thought to be open access ones ...