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Questions tagged [remote-sensing]

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.

-3
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0answers
14 views

Performing pervious and impervious classification using Landsat data and ArcMap? [on hold]

I used supervised classification in ArcMap but did not get good results. I want to classify image in 4 major classes like buildup, vegetation, barren land and water.
-1
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0answers
16 views

Pixel level NDVI calculation [on hold]

How can I get pixel level NDVI information from sentinel images? Which is the better software to do that?
2
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0answers
21 views

Smoothing MODIS LAI? [on hold]

I am trying to smooth 8 days LAI data from MODIS and managed to work around it with several algorithms such as loess, Savitzky–Golay, smooth.spline etc. This is pretty much going well if the level of ...
0
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0answers
40 views

Determining extra seed for SNIC segmentation algorithm

Here is a part of a program that do segmentation based on SNIC algorithm and indeed compute some statistics based on the resulted clusters to determine the worst outlier for each clusters in order to ...
0
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1answer
13 views

Does per-pixel viewing zenith angle (VZA) is identical between landsat sensors for a common path/row?

Due to the distance from the nadir viewing vector of the satellite, variation in viewing zenith angle (VZA) is observed from the center to the outer edges of the scene (as shown in figure one). ...
0
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0answers
29 views

Identifying rocks using Landsat 8 images [closed]

Using ArcMap, which are the best Landsat bands (and its combinations) to use to identify basement rocks (in Angola)? In Landsat 8?
0
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0answers
27 views

Aster L1T: Radiance -product to surface reflectance

Earth Engine provides access to Aster level 1 Precision Terrain Corrected Registered At-Sensor Radiance -product (Aster L1T). I would be interested to reach the surface reflectance values of the image ...
0
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0answers
8 views

How do I remove the black background of ASTER in Envi Classic 5.3 “display window”?

I want to change color or remove black bacground of my aster imagery when "save image as" from display window (that loaded as RGB to display.. is there a quick way to do it? here is the what i ask in ...
0
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0answers
37 views

Getting error running GRASS GIS 7.6.1

Here is the error notice I receive after starting GRASS GIS 7.6. I am not sure what is the source of these errors. I had reinstalled the application but it didn't fixed these errors. What are ...
0
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0answers
22 views

Algorithm(s) for Sensor Footprint at limbs

Is anyone aware of algorithm(s) that have been developed for computing remotely sensed image footprints that handle body limbs? The limb is the edge of the body / atmosphere where only the blackness ...
0
votes
1answer
21 views

How to modify MODIS subset function to download product for a specific region and time period?

I am trying to assess the land cover change that has occurred over East Asia over last 18 years only in winters (Oct-Jan) for which I want to use MOD13Q1 dataset of modis from 2000-2018. I am using ...
0
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0answers
18 views

Filter Date From FeatureCollection

I want to filter my crop data table on the basis of dates. I uploaded my file in the assets and call it. Now I am unable to filter this data accordingly datewise. The date column is added in the file ...
0
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1answer
25 views

Moisture Stress Index - how important is seasonal influence in a deciduous forest?

I want to calculate moisture stress index for a deciduous forest using the formula from the article 'Detecting vegetation leaf water content using reflectance in the optical domain' (Ceccato et al. ...
0
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0answers
23 views

Ground Control Point Experience

I have a number of aerial images that do not align with where my GPS says I am. For example, I am standing at the intersection of two roads with a Trimble R10 and a handheld IOS device with the ...
1
vote
1answer
28 views

Downloading Sentinel 2 imagery using Semi-Automatic Classification Plugin?

I have been following this video (https://www.youtube.com/watch?v=FcETq8OWM0k) to download Sentinel 2 imagery using the Semi-Automatic Classification Plugin in QGIS 3. However, when I click run and ...
0
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0answers
21 views

Statistic validation for spectral trajectories/trend from ground truth dataset

I'm doing an extraction of spectral trajectories for disturbed forest pixels using multitemporal (single scene for 20 years) Landsat Surface Reflectance products. Usually, forest disturbances are ...
1
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0answers
28 views

Calculating MODIS 8-day composite GPP product as yearly [closed]

I want to use MODIS GPP 8-day composite product for an annual time series analysis. How to calculate the annual GPP from the 8-day composite? Since the fractions represent the daily average rates of ...
2
votes
1answer
35 views

Computing the harmonic mean of an image collection in the Google Earth Engine

How can I compute the harmonic instead of arithmetic mean for a series of images in Google Earth Engine? There is a build-in function to compute the arithmetic mean and median, but there is no ...
0
votes
1answer
47 views

Extracting atmosphere opacity using Google Earth Engine?

I met some doubts when I try to extract Landsat surface reflection product's atmosphere opacity. the code is : var inCollection7 = ee.ImageCollection("LANDSAT/LE07/C01/T1_SR").filter(ee.Filter....
0
votes
2answers
36 views

Hansen Global Forest Change - Forest Loss Year - Dates Clarification

I have scoured both the GFC website, research papers and Stack Exchange, but haven't been able to find a clear and reliable explanation of what the "Year of gross forest cover loss event" pixel values ...
0
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0answers
26 views

Clip a Mask (NDSI) from another Mask (NDWI) in GEE

I have created a mask of Normalized difference Snow Index (NDSI) in the late winter using a combination of Landsat 5,7,8 imagery and I would like to only keep a remaining land features by clipping out ...
2
votes
2answers
105 views

Landsat 8 - Reflectance Values

I downloaded some Landsat 8 OLI/TIRS C1 Level-1 images from EarthExplorer. I was hoping to get reflectance data out of the blue, green and red band; however, when I opened those images in ArcMap, the ...
5
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2answers
1k views

Why is short-wave infrared portion of electromagnetic spectrum so sensitive to fire?

After attending a remote sensing workshop and using Copernicus data to monitor natural disaster scenarios, my question could not be fully answered by the instructor. All that was said, was that is in ...
1
vote
1answer
30 views

Make Level-2 Landsat images comparable with Level-2A Sentinel-2 images

Is there a way to make Level-2 Landsat images (e.g. Landsat-5 images ordered from EarthExplorer) comparable with Level-2A Sentinel-2 images? The objective is to calculate water or vegetation indices (...
2
votes
1answer
142 views

How big is a MODIS 250m pixel in reality?

How big is a MODIS 250m pixel in reality? This appears to be a question that contains its own answer, but I have several reasons to doubt that the pixel size is actually 250m x 250m: I downloaded ...
1
vote
1answer
39 views

Landsat 8 Level 2 products. Converting Pan & Thermal bands to spectral reflectance

We have downloaded around 20 Landsat Level 2 Surface Reflectance scenes for our AoI. The processed bands available in the downloaded scenes are, as you people know - Aerosol,B,G,R,NIR,SWIR,Cirrus. ...
1
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0answers
33 views

What is the 4th band in a 16 Bit 4 Band RGB TIFF? [closed]

I am using TIFF files in a project, all of which are plain RGB imagery. When imported into the software program that I use they are just automatically shown as being three bands, Red Green and Blue. ...
0
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0answers
29 views

Labeled training data for water extraction/classification

I'm working on a small project to extract water features from satellite images. In particular, I plan to use Landsat 7 ETM+ satellite images of a particular lake (it's on plain land). I have decided ...
1
vote
3answers
76 views

Bare Soil Detection

I try to find bare soil areas. Those which are bare over the whole year and those which are fresh harvest and remain bare over a certain time. I try to do this with sentinel-2 data. But the Problem is ...
0
votes
0answers
9 views

Normalizing a single band of landsat 8 imagery w.r.t an adjacent one

We have 23 landsat 8 level 2 imageries which has to be mosaiced. Based on date, we have mosaiced individual bands (B1, B2, B3, B4, B5, B6) and now it's down to 5 imageries. But we are not getting a ...
3
votes
1answer
75 views

A reproducible example for the use of separability measures in improving selection of spectral variables

I have been working with the tutorials in GEE on supervised and unsupervised classification, but I haven't come across any examples on the use of separability measures such as Jeffreys-Matusita, ...
4
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2answers
78 views

Removing noise from point cloud with lidR package

I have unclassified Terrestrial Laser Scanning (TLS) point cloud data which has some noise. Is there a function in the lidR package which can be used to remove noise?
0
votes
1answer
51 views

Sentinal NDVI Time series Chart and CLassification

I am working on NDVI time series analysis using Sentinal data and also classifying the data it will give some error and not working and how can i get the chart of three different features in ...
0
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0answers
19 views

Doing atmospheric correction of LISS-IV standard data product?

I have purchased RS-2 LISS-IV Standard Processing Level data. The product type is Geo RPC. Metadata is in IKONOS format. I want to compute surface reflectance from original DN values. What is the ...
0
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0answers
30 views

Radiometric correction of Aster Level 1T

We have to mosaic 70+ ASTER Level 1T imageries. I've splitted hdf data into 14 different tif's (3 VNIR, 6 SWIR, 5 TIR). As shown in the image imageries are of different time period. Question is, is ...
0
votes
1answer
29 views

NDVI Analysis of a small area from the year 2000- 2011 [closed]

I want to perform an NDVI analysis in a small area. I want to see the change around a river body for the year 2002, 2005, 2008, 2010 and 2011. I tried using Landsat-7 data but due to the scanline ...
2
votes
2answers
67 views

Feature normalization (scaling) for Hyperspectral images

I have been straggling with the concept of feature normalization for the hyperspectral images. Respect to my problem I have attached a picture of my problem which clearly stands the issue which I have....
0
votes
1answer
20 views

Finding sericite alteration in ENVI 5.3 spectral library?

I work on an area where there is a sericite alteration and i searched for the sericet and did not find a word. I want to know what is called sericet in the spectral library of ENVI 5.3? Sericite is ...
0
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0answers
32 views

What does Google Earth Engine's image.unmix() differentiate from other implementations?

I want to realize a project with spectrally unmixed Landsat imagery. However, I find no satisfying information on the respective GEE function, image.unmix(). I processed a few scenes with the exact ...
0
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0answers
39 views

Apparent disappearance of NLCD 1992/2001 retrofit land cover change product

I am attempting to download the national land cover datasets 1992-2001 retrofit land cover change product from the mrlc site. The product exists throughout documentation and I have not found any thing ...
3
votes
2answers
32 views

Problem downloading and using NOAA CCAP data

I am trying to download CCAP land cover data and would have expected .img or .tiff files, but the data downloads as a disk image file. I cannot figure out how to access/work with this file type. any ...
2
votes
1answer
74 views

How to de-stripe a Landsat 8 band with python?

I am working with Landsat 8 images and some of the bands have striping, e.g.: I've been going down a rabbit hole by looking for a solution for this. Does anyone know a python library that could be ...
1
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0answers
49 views

ALOS/PALSAR High Q DEM 12.5 Accuracy

Does anyone know the XYZ accuracy for the Phased Array L-band Synthetic Aperture Radar (PALSAR) DEMs (12.5 x 12.5 px)? Is there a document for reference?
0
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0answers
108 views

Blank Image After Terrain Correction

I am new to snap. I have downloaded sentinel 1 image from ESA. I have performed radiometric cal-liberation as well as speckle filtering. After that, when I tried to perform terrain correction, the ...
0
votes
0answers
53 views

Calculate Bare Soil Line Intercept using R

I am using an R package called BSL (Bare soil line), package is at https://rdrr.io/cran/landsat/man/BSL.html. The BSL package uses R's lmodel2 function (https://cran.r-project.org/web/packages/lmodel2/...
0
votes
1answer
46 views

Dataset description AREA_OR_POINT

What are the differences between these two options in satellite image metadata?
1
vote
1answer
151 views

How to add color-map scale in Google Earth Engine?

I want to add a colormap scale like below in my Earth Engine app. I cannot find a UI component for this. Can I do this in any other way in Earth Engine?
0
votes
1answer
64 views

Pleiades atmospheric correction

I have phr1a and phr1b images (Pleiades) and I need to make atmospheric correction. First, I tried to do this by using Envi FLAASH. by the way, I tried also ERDAS atcor but there was also same ...
1
vote
1answer
58 views

How to calculate average value of points located in each pixels in R?

I have a raster(.tif) and point(.shp) layer. To calculate the average value of points located in each pixels: (1) For each image pixel that include multiple points, the average value of all points ...
1
vote
1answer
63 views

How to download MODIS NBAR(MCD43B4)product?

Description: The MODIS nadir bidirectional reflectance distribution function adjusted reflectance (NBAR) product (MCD43B4), 1 km spatial resolution and a composited 16 day temporal resolution. ...