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
31 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 ...
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0answers
16 views

PolSAR pro v4.2 cannot read the data file for UAVSAR, why? [on hold]

I have 6 UAVSAR data files: as suggested by the UAVSAR PolSAR data format, the files are OK. In order to read them by PolSAR pro v4.2, I set the environment: and then in the Import ...
3
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1answer
37 views

what does it mean to store cross products in SAR product data file?

I'm reading the UAVSAR data format For definition of two types of file we have: MLC files (.mlc): calibrated multi-looked cross products, floating point format, three files8 bytes per pixel, ...
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0answers
82 views
+50

Deciding variables for image classification?

The results of an image classification may vary A LOT depending on the variables you use from the beginning. Number of classes, minimum class size, sample interval, atmospheric corrections, ...
1
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0answers
29 views

Format of SAR images

What is the format in which SAR images are stored? By format I mean when a SAR captures an image, it gets saved in what format? jpg? png? tiff? or there is some other special format? Is there a ...
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0answers
26 views

Change detection in multi-temporal SAR images [on hold]

I would like to know what are the state of the art techniques, used for performing change detection in multi temporal SAR images. The simplest of techniques are the algebraic ones,like image ...
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0answers
18 views

How to get multi-temporal InSAR data?

I am very much new to InSAR data. At the moment, i'm stuck at this website https://ursa.asfdaac.alaska.edu. Just wanna know, is it possible to get multi-temporal InSAR data for a particular region ...
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5answers
2k views

Fix Landsat 7 SLC-off in ENVI?

I have a couple of Landsat 7 images and they all have striping as a result of the SLC failure. Does anyone have any suggestions as to how to destripe the image using ENVI? I plan to use these images ...
2
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1answer
46 views

What is multilooking?

Today I found a video on youtube for multilooking the data with NEST (Next ESA SAR Toolbox) and it seems that it produces square pixel out of rectangular SAR pixels. Does it operate as simply as ...
2
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2answers
260 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 ...
3
votes
1answer
283 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 ...
4
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1answer
68 views

Free open satellite or other remote sensing data for night time?

I usually work with daytime satellite images to do some image classification (mostly Landsat data from the USGS EarthExplorer). Right now I'd like to check at some night time images to work on city ...
0
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1answer
20 views

aerosol optical depth

i want to extract aerosol optical depth on land using modis it seems like I need a value from one of these parameters between Corrected_Optical_Depth_Land and Corrected_Optical_Depth_Land_wav2pl but ...
3
votes
2answers
68 views

Why does the resolution decrease with increasing incidence angle in the Sentinel-1 SAR sattelite

On this link (Sentinel1 webpage for a SLC product), the resolution is written as a range from the highest corresponding to low incidence angle, to the lowest resolution corresponding to high incidence ...
3
votes
2answers
518 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? A short update concerning this attempt to ...
1
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2answers
905 views

Converting *.tif file into headerless (flat) binary file?

I am using NDVI files (value range -1 to +1) created from Landsat CDR images to produce a timeseries in TIMESAT software. My .tif file has following characteristics. File type TIFF,Data Type ...
1
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1answer
38 views

Calculating NDWI in Erdas IMAGINE 2014

I'm using MOD09GQ product of MODIS to calculate vegetation indices in Erdas 2014, and I was able to extract NDVI using Erdas Model Builder. What is the formula I should use in model builder for ...
4
votes
2answers
257 views

Image processing using Python, GDAL and Scikit-Image

I'm new here and I'm sorry if I do something wrong. I am struggling with a processing and hopefully I will be able to solve here. I work with Remote Sensing applied to Forestry, especially working ...
2
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1answer
245 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 ...
0
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1answer
47 views

Is there any packages to download landsat image by shapefile boundary in R or python? [closed]

I want to find a package which can automatically download images within a predefined administration boundary (shapefile format). Does anyone know a package can conduct or simplify the process?
10
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5answers
855 views

Processing full-waveform LiDAR?

Does anyone know of a good software package for processing full-waveform lidar? Also, does anyone know of a good tutorial on processing full-waveform lidar?
0
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0answers
9 views

Problem using ENVI/IDL ENVITask('BuildBandStack')

I am trying to stack 2 bands together from 2 different landsat images using ENVITask('BuildBandStack'). These are landsat images from two different years, and Band 1 in both years. When I run my code ...
1
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0answers
31 views

Hard wood tree and Soft wood(shrubs) Vegetation Differentiaton

How I Differentiate Hard wood tree (like Mango, Sal) and Soft wood(shrubs like reed) Vegetation using Multispectral or Hyperspectral Image? I have TM, ETM, OLI, Hyperion, Aster Image and ERDAS 2011, ...
3
votes
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 ...
1
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1answer
63 views

Why is azimuth resolution worse than range resolution in Sentinel1 (SAR) [duplicate]

Why is the azimuth resolution in Sentinel (SAR sensor) worse than the range resolution? The table in this link gives the resolution for SLC products aquired in the different aquisition modes. In ...
4
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1answer
77 views

Determining the best month for discriminating between different vegetation types?

I ordered and downloaded several (Surface Reflectance) Landsat 5-8 images from USGS Earth Explorer with the purpose of choosing a few of them to calculate some Vegetation Indices for each (NDVI, SAVI, ...
0
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1answer
35 views

Is there any comprehensive book or online instruction on image segmentation techniques?

I'm looking for a source to learn theoretical basis of image segmentation techniques thoroughly. The desirable book, or other kinds of source you may know, should cover the techniques that are more ...
6
votes
3answers
404 views

How to easily identify/classify coniferous forest from one date Landsat image?

I am pretty new in remote sensing and I am trying to identify/classify coniferous forest cover from single date Landsat scene. According to my preliminary web research I have these possibilities: ...
2
votes
1answer
77 views

Why does the peak of a mountain appear bright on Radar images

Why does the top of a mountain appear bright on a SAR (radar) image. I know that the peak of a mountain is subject to a layover effect, thus appearing closer on the radar image than the bottom part of ...
0
votes
1answer
23 views

How do you digitize an ROI in envi 5.2?

Is there a way to digitize an ROI in ENVI 5.2 that is larger than the area shown in the viewer? I'm setting up labs for an intro to RS class, and the next step is to subset the image to get rid of ...
2
votes
2answers
291 views

Spectral profile (z-profile) viewer for ArcGIS

I have multilayer raster with 6 bands. Is there a way to select one specific pixel and to display the z profile (the values of each band) for this pixel as a chart or table? I am looking for a tool ...
0
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3answers
290 views

What is an inexpensive way to map underground Utilities, like pipes, gas lines and telephone lines

I just got hired on to a small local government i am sill learning the ropes as a GIS Analyst. What is an inexpensive way to map underground Utilities, like pipes, gas lines and telephone lines? What ...
0
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0answers
16 views

Is this terminology I'm using is suitable for the field spatial analysis of time series?

I'm going to apply time series concepts to an satellite image, but instead of using time data located on the 'X' axis, I want to use spatial variations on that axis. In addition, the 'Y' axis keeps ...
4
votes
2answers
117 views

“Official” definition to hyperspectral sensor

I was checking in the literature about a formal definition for hyperspectral sensors, and the most complete definition I found was from The Center of Space Research (@ University of Texas in Austin): ...
2
votes
1answer
48 views

Difference between a spectroradiometer and multispectral sensor

Let's take as an example of a spectroradiometer MODIS, and as an example of a multispectral sensor the Landsat8 (OLI). What is the difference between these two sensors? Should we compare a ...
18
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10answers
11k views

What is the best open source software package for Remote Sensing?

Here are many questions with great answers about open source GIS software. I am wondering, what is the best open source software package for Remote Sensing? I would like to learn it and to use in my ...
1
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1answer
477 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
vote
1answer
31 views

Does satellite imagery have a unique azimuth for each of its spectral bands?

Does satellite imagery have a unique azimuth for each of its spectral bands? Is it right to say that if a sensor has 8 spectral bands, then it may have 8 different azimuth angle?
1
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0answers
35 views

Enhancing/smoothing Landsat 8 image using ArcGIS Online?

I understand that Landsat 8 is 30m resolution, but is there any technique that can be used to smooth/enhance the NDVI or Agriculture Landsat layers in an ArcGIS Online (AGOL) web map? I have adjusted ...
2
votes
0answers
24 views

Important to perform atmospheric correction when attempting to identify coral reefs?

I want to identify coral reefs using multi-temporal Landsat data and Lyzenga's Transformation method. In relation to pre-processing the image, should atmospheric correction be done or not? If not, ...
2
votes
1answer
53 views

Can a satellite go over the same area in different passes overtime

Can a sun-synchronous satellite (let's consider Sentinel-1) go over the same place, one time in an ascending pass and the next time (or few times after) in a descending pass?
0
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1answer
47 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 ...
1
vote
1answer
90 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
votes
0answers
49 views

DEM input problem using ARCSI Landsat 8 batch processing

I'm trying to use ARCSI in Linux to process a batch of Landsat 8 images. I'm using the arcsibuildcmdslist.py to build the arcsi.py final command. I'm having problems in the input DEM ...
3
votes
1answer
59 views

Reading Synthetic Aperture Radar raster images using python

Is it possible to read and modify Synthetic Aperture Radar raster images using python? gdal is not able to understand their Type which is Binary (application/octet-stream). One can find sample radar ...
1
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0answers
27 views

What does “Information [18]: Select at least one signature” in the semi automatic classification plugin mean?

I am using the semi automatic classification plug in to classify vegetation and water in a satellite image. I create training shp and signature list. When i hit "classification preview" it gives me ...
0
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0answers
21 views

Geometric correction using topographic maps?

I am researching LULC change detection using Landsat 7 etm + image in 2000 and Landsat 8 image in 2014. Both are L1T images. Do I need to do geometric correction using topographic map for my study ...
0
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0answers
19 views

What's the relationship between visibility and reflectance?

I'm having a problem with the atmospheric correction of remote sensing images. Until now I believed that increasing the visibility (or decreasing AOD) resulted in an increase in reflectance but now ...
1
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1answer
308 views

Is Landsat 4-5-7 L1G geometric corrected?

Im using Landsat L1G for our project and need L1G to be geometric corrected for later use. One thing I know for sure that L1G need to be employed a Digital Elevation Model (DEM) for topographic ...
2
votes
1answer
49 views

Get resolution and whether right/left looking from sentinel metadata

Is it possible in Sentinel hub products to know the resolution of the product and whether the SAR was right or left looking at the scene? I know that it's possible to know if the SAR was operating in ...