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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17 views

qgis/remote sensing/OTB : needs & expectations? [on hold]

As part of a mission project, I talk currently with a significant contributor to the development of qgis. We wonder about needs & expectations of the users and developers regarding remote sensing ...
2
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1answer
18 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 ...
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0answers
22 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,...
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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?
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1answer
29 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 ...
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1answer
95 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? ...
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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 ...
0
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1answer
268 views

Calculate NDVI with converted canon sx260 hs

I have converted my canon sx260 hs so it can capture NIR part of specter. Can anyone tell me how can i calculate NDVI now? My guess is that on the blue channel is now NIR value and Green channel=(...
3
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1answer
30 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
83 views

Extracting Data from Raster based on Aspect Raster file

I have 2 rasters, ones shows aspect and another shows date of snow thaw. I want to extract the date of snow melt based on values from the aspect raster. For example I want all the snow thaw dates from ...
0
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1answer
16 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 ...
2
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1answer
278 views

applying savitzky golay filter to modis ndvi data

I want to smooth the ndvi MODIS 16 bit integer data .tif for LULC classification . i have timesat 3.1 software on windows but i don't how to apply the SG filter . i am not that good in programming . i ...
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2answers
58 views

Landsat 8 cloud detection without band 9

What is the best possible way to create a cloud mask of a Landsat 8 scene without using band 9? I think the best way will be to determine the cloud cover by thresholding in the Panchromatic band and ...
6
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4answers
3k views

Seeking alternative to ERDAS Imagine? [closed]

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 I do not understand why there such a conflict in the first place. ...
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 ...
3
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1answer
473 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
28 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
183 views

Spectral Signature Extraction using landsat 7 and MODIS

I am working on differentiating cocoa plants from other vegetation types using 4 epoch bwt 1980-2010. I need to extract the spectral signature for cocoa plants and other known features. I plan using ...
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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?
2
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1answer
487 views

Python script for dark object subtraction on Landsat 8 Imagery

Does anyone know of any python scripts that will allow me to conduct such a process? I am limited to open source software and have minor experience in Python.
4
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3answers
812 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.
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2answers
54 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 ...
1
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1answer
241 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 ...
2
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1answer
304 views

Handling MOD13Q1 NDVI Product Quality Assessment (QA) flags?

I am working on MOD13Q1 NDVI Product and i want to apply Savitzky Golay filter for smoothing Ndvi time series using Quality Assessment(QA) flags. I studied MOD13Q1 NDVI help file and found that ...
1
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1answer
27 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 ...
2
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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 ...
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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 ...
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
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1answer
4k views

How to import HDF (L1G) files into ArcGIS for Desktop?

I have downloaded satellite imagery from GLCF website, it has downloaded with .L1G file extension, I am not able to open this file in ArcGIS as well in Erdas, so please let me know how to open this.
3
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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 ...
2
votes
1answer
77 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 ...
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0answers
18 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 ...
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
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2answers
531 views

Classification, Change detection and NDVI Using (landsat2 MSS), (landsat5 TM), (Landsat7 ETM+) and (Landsat8 OLI)

I have 5 Landsat images for the same study area. One of them in 1975 (Landsat 2 MSS), two in 1985 and 1995 (Landsat 5 TM) and one in 2005 (Landsat 7 ETM+) and the last one in 2014 (Landsat8 OLI). I ...
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 ...
0
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1answer
224 views

NDVI values for MODIS images [duplicate]

I have downloaded NDVI MODIS 500m image i.e. MOD13A1. From the hdf format that i got i converted them into tif format using the HEG tool. The images that i got some are showing pixel values -32767 to ...
3
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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
64 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
39 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
vote
0answers
22 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.
5
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2answers
2k views

Open source solutions for Landsat-8 mosaicing and correction?

I am familiar with the major commercial remote sensing packages (ENVI, IDRISI ERDAS, etc), but I haven't previously had the opportunity to utilize open-source solutions. I have a several new Landsat-...
4
votes
3answers
167 views

Where / How to download Sentinel 2 Images

I need Sentinel 2 imagery of Nigeria, I signed up in Copernicus Scihub but typing Nigeria into the text box no results appear. I must be doing something wrong, how can be possible that they do not ...
3
votes
2answers
184 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 ...
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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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. ...
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1answer
39 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 ...
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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 ...
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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 ...
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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