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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11
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1answer
842 views

Gram-Schmidt pan-sharpening in QGIS?

I need to perform Gram-Schmidt pan-sharpening, I don't have access to ArcGIS or ENVI so have been using QGIS. Is there any plug-in or similar capability that is available to perform Gram-Schmidt pan-...
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2answers
38k views

Download new SRTM 30 meters

I read about the new version of the digital elevation model at 30 meters (SRTM 30 meters), but I can not find from were I can download it. some sources: http://glcfapp.glcf.umd.edu:8080/esdi/index....
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4answers
593 views

Looking for a web service for change detection

I'm looking for service that provides me a change detection service based on a database of remotely sensed data. Has anybody happen to know such a service? The service I am looking for is a geoportal ...
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5answers
2k 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?
10
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2answers
484 views

Why Landsat ETM+ panchromatic band' wavelength steps over visible range?

The Landsat ETM+ band-8 (Panchromatic) is identical to Landsat-8 OLI' Panchromatic band-8 in terms of spatial resolution i.e. 15 x 15m cell size. However, there is great difference in the wavelengths ...
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2answers
1k views

Methodology for Hansen classification of Global Forest Watch?

I have just discovered amazing Hansen´s classification about forest loss and re-growth, available at http://www.globalforestwatch.org/, published in Science, 2013 as: Hansen, M. C., Potapov, P. V, ...
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6answers
896 views

Resources for Calculating the Geometry In Oblique Photographs

Currently I am using supervisory classification algorithms to calculate the landuse within a certain image, the issue being the images are sourced from high oblique photography. I know the focal ...
10
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1answer
681 views

50cm imagery - aerial or satellite?

The area of interest is 1450 km2. My options are: 50cm newly collected aerial natural color imagery for $28,300 OR 50cm recent archival satellite imagery (includes near IR band) for $20,600 The ...
10
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2answers
1k views

Calculate potential of solar radiation on rooftops (without LiDAR data)

I'm trying to calculate the solar radiation for rooftops, but I have a big problem, I don't have LIDAR data. I need to give the buildings the information of height. I've tried to do these, but for a ...
10
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3answers
2k views

Handling mountain shadows when classifying Landsat 8

I'm trying to classify some area in northern Mongolia using Landsat 8 satellite images from 2013. Since the recordings were made in winter, the sun is very low at the acquisition time. Therefore there ...
9
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1answer
2k views

Examples of GIS or Remote Sensing in movies

Looking for examples where GIS or RS has been a part of a movie plot. I'm trying to put together a "GIS & RS and the Cinema" class, in which examples of GIS & RS are shown. Those examples will ...
9
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1answer
7k views

Importing multiple stacked raster images in R?

I would like to import all multiple mosaic rasters (each mosaic is composed by 7 layers) from indicated folder into my R. Then access them as single multilayers rasters. So I did: # read all mosaics ...
9
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3answers
893 views

Sentinel-2 projection shift

I recently observe a shift in the geographic projection of Sentinel 2 data. Please see the screenshots below for clarification (Granule T33UXP, Band 8 only). The first image was taken on 20160314, the ...
9
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1answer
2k views

Ditch Extraction using LIDAR DTM (1m resolution)

I'm trying to extract ditches using the LIDAR DTM using the software eCognition but I am actually having a hard time since the paper where I based my workflow entitled "Ditches’ network extraction and ...
9
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2answers
1k views

Retrieving heights of buildings using remotely sensed data (except lidar)

How can I get the height values of buildings from a certain sector a city without going into the field to collect data? Is there anyway to do via satellite imagery, SRTM, ASTER GDEM or any DEM for ...
9
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2answers
349 views

Identifying Joshua trees with LiDAR data?

I'm working on a LiDAR project to determine where Joshua trees are located within a specified study area. Due to the vegetation cover being so sparse, there are really on 2 canopy species there, which ...
9
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1answer
5k views

Atmospheric Corrections for Landsat 8 OLI Using Orfeo Toolbox

I am trying to correct some Landsat 8 OLI imagery using the Orfeo Toolbox Optical Calibration tool via QGIS. I've retrieved data from Aeronet as well as relative spectral response data for the OLI ...
9
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4answers
1k views

Preferred programming language and software for entire remote sensing workflow?

I have been involved in remote sensing for some years now during studies. I am wondering which combination of software and image processing modules would be most suitable for an entire process chain ...
9
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1answer
1k views

Extracting values at specific latitude,longitude from MODIS swath data

I am trying to determine the amount of precipitable water vapor (PWV), ozone and aerosols as a function of time over specific spots on the Earth, namely our astronomical observatories. To do this, I'...
9
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1answer
958 views

Counting number of plants in area using images from UAV? [closed]

How do I count the number of pineapple plants in a 1-hectare block? I have heard of these algorithms but I don't know how to do it. I'm still a newbie of QGIS, ArcGIS and ENVI. I have the NIR, RGB, ...
8
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1answer
6k views

Reprojected MODIS NDVI has range from -32768 to 32767, expected -1 to 1

I'm new to StackExchange and to remote sensing. I am working with MOD13Q1 250m 16-day MVCs. My goal is to use NDVI time-series to classify cropping pattern and crop type, then link this data to ...
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2answers
16k views

image segmentation of RGB image by K means clustering in python

I want to segment RGB images for land cover using k means clustering in such a fashion that the different regions of the image are marked by different colors and if possible boundaries are created ...
8
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2answers
6k views

what's the difference between spectral signature and features in remote sensing?

I would like to understand if is there any difference or relation between spectral signature concept and features in remote sensing?
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3answers
3k views

Remove clumps of pixels in R

I would like to remove isolated pixels (or clumps of pixels <9) from my raster image. library(raster) # create some raster data r <- raster(ncols=12, nrows=12) set.seed(0) r[] <- round(runif(...
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1answer
1k views

Remote Sensing Landsat Surface Reflectance and Albedo

I'm pretty green when it comes to RS and I'm doing this school project that I need help with. The project is to measure albedo changes for the tongue of a glacier and I'm using R programming to do it. ...
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2answers
3k views

Landsat8 DN to TOA Reflectance (minus values)

I'm learning how to perform atmospheric correction manually, hence not using the automated methods available in ENVI metadata (band 1) for my Landsat 8 scene is as follows; RADIANCE_MULT_BAND_1 = 1....
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3answers
2k 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: ...
8
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1answer
1k views

Why does Landsat 8 panchromatic band NOT include the infrared? [duplicate]

The panchromatic band on Landsat 8 OLI sensor (band 8) covers a narrower portion of the spectrum than the corresponding band in Landsat 7 ETM+: 0.50 - 0.68 micrometers (L8 OLI) in contrast to 0.52 - 0....
8
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1answer
2k views

What is the range of values of Sentinel-2 Level 2A images?

I found in Level 2A Product Format Specifications Technical Note page29 that: "The L2A Quantification Value is aligned with the L1C Quantification Value of the L1C product from which the L2A product ...
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2answers
18k views

Difference between irradiance and radiance, remote sensing reflectance and water leaving radiance

I've been trying to lay my hands on textbooks, etc, that explain the differences between the remote sensing terms in lay man language. radiance and irradiance remote sensing reflectance and water ...
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1answer
1k views

River boundary (bank) extraction from LiDAR

Is there any way to extract a river boundary (bank) from LiDAR data and its products (DEM, intensity image and slope) automatically? Digitizing is very time consuming.
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2answers
384 views

Aerial LiDAR: What is an acceptable resolution?

I am in the process of initiating a project involving laser scanning. The area to be scanned i s approximately 5000 km². We are initially going to use the data to create a solar potential application, ...
8
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2answers
1k views

Why is there a difference between NDVI using Sentinel 2, in ArcMap & QGIS?

I have been trying to calculate the NDVI for a scene using Sentinel 2 bands 4(red) & 8(NIR). I first did it in ArcMap and then QGIS. In both softwares, I used the raster calculator and included ...
8
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1answer
690 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 ...
8
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1answer
699 views

Remote sensing for Nepal Earthquake [closed]

To any experts who can provide remote sensing data that can help assess impact and damage of nepal earthquake we really need your help to ensure aid is well targeted. Existing data so far is here If ...
8
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1answer
605 views

What GIS applications use Google Glass?

From techcrunch. I see a lot of press coverage about Google Glass, yet I haven't seen details of GIS apps that use it. What GIS applications use Google Glass?
8
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1answer
2k views

How to perform unsupervised classification of LANDSAT time series using Grass?

I'm using GRASS to perform an unsupervised classification on a time series of LANDSAT images (monthly temporal res, over 30 years), in order to compare land cover change in a particular area. I'm ...
7
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5answers
3k views

Which methods are most suited to classifying urban areas from Landsat imagery?

I am trying to use Landsat data to map urban extents over time. I need to perform a classification into built up / non built up areas. I am new to image classification. I have access to the following ...
7
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3answers
2k views

Atmospheric correction algorithm in Python or R for Landsat 7 ETM+

I am looking for an algorithm which can be tuned in python or R for atmospheric correction for Landsat 7 ETM. Searching Google I have found only a few algorithms in ENVI or ERDAS which are not ...
7
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4answers
850 views

Automating detection of clearcut areas in optical satellite imagery?

Given optical satellite or aerial imagery of a resolution similar to the image below, is it possible to accurately detect clearcut areas? Is there research or documentation that supports a specific ...
7
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2answers
1k views

Extracting building footprints from Sentinel-2 imagery

My attempt to extract building footprints from Sentinel-2 images using machine learning algorithm trained on Sentinel-2 images produced a lot of false positives and there is no sign that the algorithm ...
7
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2answers
965 views

Why Sentinel-2 bands have different spatial resolution

Sentinel-2 has 13 bands with 3 distinct resolutions. Band 1 60m Band 2 10m Band 3 10m Band 4 10m Band 5 20m Band 6 20m Band 7 20m Band 8 10m Band 8A 20m Band 9 60m Band 10 60m Band 11 20m Band 12 ...
7
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2answers
538 views

Are PDAL or PCL capable of producing LiDAR grid metrics?

I typically use Windows-based FUSION to generate grid metrics, which can be used to describe forest structural characteristics. From the FUSION documentation: GridMetrics computes a series of ...
7
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3answers
13k views

Download high res NDVI imagery

I'm trying to find a good source of NDVI imagery, but I'm struggling to find proper high res imagery, particularly for northern Europe. Does anyone have references to high res imagery, that is ...
7
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2answers
4k views

processing MODIS hdf files with gdal

I'm trying to open an MODIS file (hdf format) with gdal in a python script under windows OS. I use the HDF4 driver, as read at http://www.gdal.org/frmt_hdf4.html. But when I run it I got this error ...
7
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1answer
2k views

Calculating EVI from Sentinel 2 imagery gives difference in results between ArcMap & QGIS?

Though EVI coefficients have not been developed for Sentinel 2 imagery, I am using the same coefficients used for MODIS to calculate EVI for Sentinel imagery. I know that Sentinel 2 imagery is TOA ...
7
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2answers
6k views

Opening image files with Sentinel 2 toolbox

Anyone worked with the Sentinel-2 toolbox/SNAP? It doesn't support sentine-2 data to be opened directly. I tried opening .safe, .zip and .xml files.
7
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2answers
6k views

How to write every raster from a list of rasters?

I have created a list of rasters - "norm" and run a several loops. Now I would like to write every created raster from "norm" (containing 1 layer) into one raster, having its specific name. # I can ...
7
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3answers
1k views

Programmatically Downloading Landsat Images

There was a very similar question to this one here , but it specified Landsat 8 images; I'd just like to be able to download ANY landsat images, given latitude and longitudes as inputs. Just wanted ...
7
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5answers
469 views

What technique is used to acquire client location?

So far I know how to grab the client location to a application or web application by using the users geolocation or GPS location. I remember the possibility of finding the users approximate location ...