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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26
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7answers
4k views

Machine Learning Algorithms for Land Cover Classification

I am interested in learning what software exists for land classification using machine learning algorithms (e.g. k-NN, Random Forest, decision trees, etc.) I am aware of the randomForest package in R ...
23
votes
5answers
4k views

OpenSource Remote Sensing Tools for Classifying Roofs

with envi image processing and classification tools, you can get roofs from images with some spectral value and then you can convert it some vector data for your app. in python with OpenCV which have ...
22
votes
12answers
15k 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 ...
21
votes
5answers
7k views

What is Change Detection and how I can perform such analysis with open source tools?

From wikipedia page: Change detection for GIS (geographical information systems) is a process that measures how the attributes of a particular area have changed between two or more time periods. ...
21
votes
6answers
5k views

Is GPS more accurate on specific hours of the day?

I have heard that the GPS system is more accurate, and less accurate on some specific hours on the day. If this is true, how can I get the information on when GPS is more or less accurate at my ...
19
votes
3answers
5k views

How to produce high-resolution DEMs from new Sentinel-1 data?

This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
18
votes
9answers
5k views

Which Tools do you use for Classification of Remote Sensing Data?

Which tool do you prefer to use for classification of remote sensing data, e.g. classifying land use, and why? Which other tools have you tried, and why did you decide against them?
17
votes
6answers
790 views

What are people using LANDSAT data for?

Obviously it's potentially a very powerful tool, but I'm curious as to what practical applications people are using it for? Admittedly, this is a very broad question... The reason I ask is because ...
16
votes
3answers
5k views

Which remote sensing satellite is best used for vegetation extent mapping

I'm currently writing an assignment for my remote sensing class and while I think I have correct answer was wondering what people who do this stuff for a living think. The question is: which ...
16
votes
4answers
2k views

Is there a tool that performs automatic recognition of buildings?

I'm wondering if there is a tool, which takes a satellite map of a region, detects typical buildings and allows the user to review its result (check, whether the tool correctly identified the ...
15
votes
3answers
3k views

Is there a way to automate the preprocessing of LANDSAT data?

I'm currently enrolled in a remotesensing course, using LANDSAT data. Part of my course is about standardizing the scenes based on radiance values. I assume that because this is such a tedious task, ...
15
votes
3answers
1k views

Alternative vegetation indices

I have been using NDVIs with limited success to identify trees in the central Great Plains region of the USA. The problem I have been encountering is that reflectance from farm fields/pastures have ...
14
votes
9answers
951 views

What is the best/easiest way to obtain temporal Landsat imagery?

It's been awhile since I've dealt with optical imagery. I need to perform a land cover classification at mid-latitudes using several LANDSAT scenes. I've noticed that some online tools are still ...
14
votes
4answers
8k views

free GIS software that can orthorectify?

Would someone care to recommend a free and/or open source GIS application that can orthorectify map images?
14
votes
3answers
797 views

Ecological geospatial conundrum

I am looking for a different, more elegant solution to a spatial statistics problem. Raw data consists of an x-y coordinate for each individual tree (i.e. converted to a point .shp file). Although ...
13
votes
9answers
1k views

Is there a smartphone app for mobile asset logging?

I'm after a recommendation for a smartphone app (iPhone or Android) to log asset information for litter bins. I need the following features GPS geotagged photos Form with drop down menus for user ...
12
votes
5answers
4k views

Recommended programming language for remote sensing?

I am beginning studies that hopefully will lead to a long career as a remote sensing specialist. I am currently working with ArcGIS for some applications and learning ENVI for others. I have ...
12
votes
3answers
5k views

Land Cover Feature Extraction from Satellite Imagery

I'm interested in a low-cost or open source solution for creating land cover GIS layers that utilize both spectral and textural extraction algorithms. I have used PCI Geomatica, ENVI, and Feature ...
12
votes
1answer
1k views

automating roof orientation detection from satellite imagery

A while ago I did a neighbourhood roof orientation survey for solar panel deployment, by visually checking each roof and marking individually whether they were south or almost south-facing. As this ...
12
votes
2answers
1k views

NDVI in urban environment

What considerations should be taken into account when trying to derive a NDVI from an urban environment? I pulled a tree canopy layer from LAR-IAC data and used an NDVI of 0.38. However, this FAQ on ...
12
votes
5answers
13k views

Source for high-resolution satellite images free/low-cost?

I am doing a household survey in Kenya, and I need to ensure that my survey team visits every house within a given area. I've been going to google maps and right-clicking on roofs to get coordinates ...
11
votes
2answers
610 views

How sensitive is Landsat to atmospheric correction?

How important is it to correct Landsat for atmosphere, haze and convert DN to reflectance? What impact does it have on the results, say for many of the vegetation indices?
11
votes
1answer
657 views

Multispectral image segmentation for natural-resources applications using R

R has the capacity for image segmentation, although all of the examples I have come across utilize a single band for the segmentation (example). I am interested in combining R's capacity for random ...
10
votes
4answers
399 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 ...
10
votes
4answers
1k views

Python resource for remote sensing? [closed]

I am looking for a good resource (MOOC, book, etc..) to teach Python for remote sensing applications. I am already familiar with http://www.rsgislib.org/ - are there any other resource out there for ...
10
votes
1answer
950 views

How to compare aerial and satellite images for land use analysis?

I am interested to compare the land use-cover dynamics for four periods: 1950s, 1980s, 1990s and current for a certain area having a max size of 5000 ha. For the first three periods detailed aerial ...
10
votes
2answers
625 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
votes
1answer
236 views

Automated detection of tracks

Given an area with depressions in open area from; say all terrain vehicles driving on soft surface. The vehicles will cause parallel depressions (paths) of about 10-20 centimeters in depth and around ...
9
votes
5answers
1k 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?
9
votes
6answers
646 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 ...
9
votes
2answers
599 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, ...
9
votes
2answers
2k views

How do you explain that band width and relative spectral response of MODIS band do not match?

To define relative spectral response, I referred to EFFECT OF RELATIVE SPECTRAL RESPONSE ON MULTI-SPECTRAL MEASUREMENTS AND NDVI FROM DIFFERENT REMOTE SENSING SYSTEMS by David James Fleming, 2006. ...
9
votes
2answers
174 views

How precise are overpass times of sun-synchronous satellites?

sun-synchronous satellites, as their name say, acquire scenes at the same solar time of the day when they pass over the same location. According to this site, sun-synchronicity is achieved by taking ...
9
votes
1answer
5k views

How to fill gaps in SLC-Off Landsat 7 ETM+ Images with QGIS?

Explanation of the problem: On 31 May 2003 the Landsat 7 Enhanced Thematic Mapper (ETM+) sensor had a failure of the Scan Line Corrector (SLC). Since that time all Landsat ETM+ images have had ...
9
votes
2answers
300 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, ...
9
votes
1answer
515 views

Most Effective Format to Manage Aerial Photography for Viewing Only

What is the most effective format to manage aerial photography for viewing in ArcGIS? I manage several datasets of Aerial Photography at a few different companies. I have backups of the original ...
9
votes
1answer
1k views

How to pan-sharpen Landsat images for image-classification in GRASS?

I'd like to learn how to do an unsupervised classification of a Landsat scene using i.cluster > i.maxlik in GRASS using pan-sharpened 15m-resolution images (the example given in its Wiki uses the ...
9
votes
4answers
925 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 ...
8
votes
2answers
3k views

What are LiDAR returns?

Can someone help with an explanation and some references, in order to understand the nature of return pulses within a LiDAR system.
8
votes
2answers
1k views

Extracting roads out of Landsat raster images

For a study into the expansion of road networks in the rainforest I am trying to extract roads out of Landsat images. We already have sharp and cloud-free composites on which the roads are clearly ...
8
votes
1answer
529 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 ...
8
votes
1answer
208 views

Confidence in pan-sharpened classification?

I pan-sharpened one Landsat Image on ERDAS using the resolution merge resource, with brovey transform and nearest neighbor techniques. But I was told that in terms of land-use classification, it would ...
8
votes
1answer
577 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.
8
votes
1answer
3k 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 ...
8
votes
2answers
5k views

Difference between Albedo and Surface Reflectance

Can anyone tell me what is the difference between Albedo and surface reflectance? I know for sure that they are not the same. Any links / comments are most welcome. Thanks GBh
8
votes
3answers
587 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 ...
8
votes
1answer
539 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?
7
votes
2answers
14k 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....
7
votes
2answers
2k 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?
7
votes
1answer
6k views

Panchromatic Image association with high spatial resolution

How and Why is a Panchromatic Satellite Image associated with high spatial resolution? I googled and found that it is a single band image, but then why is it called pan-chromatic(All Colors). Does it ...