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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.

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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 ...
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1answer
21 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 (...
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1answer
105 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 ...
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0answers
18 views

How to get pixel value from a remote sensing image ti a CSV?

I have a Pleiades and I need to perform the water coloumn correction with the Lyzenga (1981) method using ArcGIS. So I have to define small areas (30x30pixel) at different depth and I have to extract ...
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0answers
12 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. ...
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0answers
30 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. ...
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0answers
25 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 ...
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3answers
57 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 ...
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0answers
6 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 ...
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0answers
59 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, ...
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2answers
54 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?
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1answer
44 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 ...
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0answers
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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 ...
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0answers
23 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
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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 ...
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2answers
46 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....
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1answer
16 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 ...
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0answers
21 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 ...
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0answers
32 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 ...
2
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2answers
20 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
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1answer
62 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 ...
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0answers
38 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?
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0answers
51 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 ...
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0answers
45 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/...
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1answer
41 views

Dataset description AREA_OR_POINT

What are the differences between these two options in satellite image metadata?
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1answer
82 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?
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1answer
41 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 ...
0
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1answer
40 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 ...
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1answer
40 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. ...
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1answer
156 views

InSAR processing: why can't we just compute distances directly from time delays?

My question can be very basic, but even after studying quite a few tutorials on InSAR processing, I still do not understand one thing: if we know a wavelength, speed of light, a time delay it takes ...
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1answer
35 views

Can radiometers measure radiations in the infra-red at night?

I started reading about passive sensors and radiometers in particular. I know that microwave radiometers work day and night and in cloudy conditions. Thermal radiometers can measure energy during the ...
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1answer
64 views

Performing Supervised Classification of Houses in Africa using ArcMap?

I am doing a supervised classification in ArcMap to classify land cover types in a study area in Africa. I am using RapidEye satellite imagery (Planet Labs) and they have 5 bands: blue, green, red, ...
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1answer
33 views

How to calculate an incidence angle raster for a radarsat 2 scene using gdal / python?

I want to make a raster band that gives the incidence angle for each pixel in a radarsat-2 scene. I know this is possible using the information given in the product.xml file (below), but I'm not ...
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1answer
109 views

How do I create a binary mask using Pixel values from a Numpy Array over a certain value (i.e. >1000), in Python [closed]

I would like to create a binary mask using the height values from a Digital Elevation Model, and export this out as a tif. For example, generate a mask for areas over 50m My code so far: from osgeo ...
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1answer
66 views

How to mask out the shadows in Sentinel images using Google Earth Engine

This question is an addition to this question. Rodrigo E. Principe showed how to mask out the clouds as the answer of the asked question. I am wondering if there is a way to mask the shadows as well. ...
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2answers
44 views

Do I need to do Radiometric Normalization for time series analysis, if I'm using L2_Landsat8_SR data?

I'm doing some forest change detection across several years using L2_Landsat8 Surface Reflectance data. And I am implementing the method available in R (landsat::relnorm) for relative radiometric ...
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1answer
33 views

Focal length vs Principal point

I have set of areal imagery. One of a parameters I get with images is camera's Principal Distance , what I'm looking for is Focal length, but I don't have Focal length at the moment I tried to ...
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0answers
52 views

How to detect cloud's shadows with Sentinel2/SentinelHub?

I'm trying to detect clouds and their shadows on Sentinel2 images with SentinelHub service. For clouds detection, SentinelHub team has developed a good tool but I would like to detect cloud's shadow ...
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1answer
33 views

Appropriate resolution for regression analysis

I'm using ArcMap 10.3. I'm a student working on a research problem where I'm taking Landsat imagery (at 30-meters resolution) and regressing it against other datasets captured at different scales (up ...
0
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1answer
25 views

What's the timezone of 3-Hourly TRMM Data?

I am using google earth engine just to print the timestamp here of TRMM Data. I am using the geometry of a part of Chennai which is in India. // Filtering Data with Date and Geometry var Data1 = TRMM....
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1answer
61 views

What's the time zone of the timestamp of LANDSAT Images?

I am using google earth engine just to print the timestamp here of LANDSAT Image. I am using the geometry of a part of Chennai which is in India. // Filtering Data with Date and Geometry var Data2 = ...
2
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0answers
172 views

Sentinel 2 preprocessing with R

I need to transform Sentinel 2 L1C imagery to preprocessed Level 2A data. Ideally this should happen in R, as the remaining processing stack is already done in R. Are there ready preprocessing ...
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1answer
60 views

Performing Supervised Classification on Sentinel Image using ArcGIS Desktop?

Is it possible to perform supervised classification on Sentinel Satellite Image with the minimum error. I compared two raster, one being the manual classification of an area using Photoshop CS6 and ...
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1answer
68 views

Why is satellite imagery data delivered as signed 16 bit integers?

Landsat 5 tm reflectance product images are delivered as signed 16 bit images, why is this preferred to unsigned 8 bit that the DN's are stored as level 1 products for the same satellite? Look at ...
0
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1answer
119 views

Google-Earth-Engine + Jupyter : filterBounds not working in Landsat imageCollection

I have a simple problem of not being able to select a single Landsat image using filterBounds within Jupyter environment. It used to work just fine in Earth Engine's online interface. I don't know why ...
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0answers
36 views

Automatically Recognised Targets for Combined Laser Scanning and Photogrammetry

I'm currently performing an engineering honours thesis on terrestrial photogrammetry and laser scanning in Archaeology. Both methods will be used to document a single location first and analysis will ...
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1answer
42 views

Seeking algorithms for DEM generation? [closed]

What are the different algorithms employed for the generation of a Digital elevation model from images captured using an unmanned aerial vehicle ?
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1answer
52 views

How to Import the geometry/feature collection which is in GeoJSON format into Google Earth Engine?

I have a GeoJSON file. I have opened it in Sublime Text Editor How can I import it in Google Earth Engine?
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1answer
93 views

How to Import the Multipolygon with GeoJSON code in Google Earth Engine?

I have to import a MultiPolygon in Google Earth Engine and what I have is just this. {"type": "GeometryCollection", "geometries": [{"type": "MultiPolygon","coordinates": [[[[102.0, 2.0], [103.0, 2....
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1answer
63 views

EVI2 value calculated from MODIS MOD09Q1 not bounded by -1 to 1

I'm trying to derive from MODIS 8 day composite MOD09Q1.006 product My formula follows the standard interpretation: EVI2 = 2.5(NIR-Red)/(NIR + 2.4*Red+1) I already know that MODIS bands for NIR ...