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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22
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5answers
2k 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 ...
19
votes
7answers
2k views

Machine Learning Algorithms for Land 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 ...
19
votes
6answers
2k 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
5answers
3k 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. ...
19
votes
9answers
4k 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?
18
votes
6answers
652 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 ...
15
votes
10answers
8k 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 ...
15
votes
3answers
3k 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 satilite ...
15
votes
4answers
625 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 ...
14
votes
7answers
662 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
2answers
2k 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, ...
14
votes
3answers
632 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 ...
14
votes
3answers
663 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 ...
13
votes
8answers
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
4answers
5k 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?
11
votes
2answers
509 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
670 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 ...
10
votes
5answers
2k 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 ...
10
votes
3answers
3k 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 ...
10
votes
1answer
617 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
788 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 ...
9
votes
6answers
496 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
1answer
292 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 ...
9
votes
2answers
241 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
207 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 ...
8
votes
4answers
295 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 ...
8
votes
1answer
204 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
2answers
601 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. ...
8
votes
1answer
859 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 ...
8
votes
4answers
698 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
1answer
477 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
votes
3answers
4k views

Best 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 ...
7
votes
5answers
666 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?
7
votes
2answers
735 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 ...
7
votes
1answer
400 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 ...
7
votes
1answer
2k views

Open Source Remote Sensing vs eCognition, ERDAS etc Is it worth it?

What, if any, would be the main benefit of using a commercial tool like eCognition (in particular) or ERDAS as opposed to something like Orfeo Toolbox or OpenCV? (Feel free to suggest other open ...
7
votes
1answer
3k 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 ...
7
votes
5answers
238 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 ...
7
votes
1answer
205 views

How to decide possible areas for water retention using lidar

I have lidar imagery for a watershed and am trying to process it so that a landowner know if they can hold water on their property or where they can hole the water (this is the more important part). ...
7
votes
2answers
476 views

How to perform enhancement operations on an satellite imagery in QGIS?

I am a new user of QGIS please suggest how to perform image enhancement operations on an satellite imagery like ratioing, contrast stretching, edge engancement, filtering etc. in QGIS?
7
votes
1answer
306 views

How to produce a vegetation stress map utilizing the spectral blue shift of the red edge?

I am interested in mapping vegetation stress utilizing the blue shift to the red edge phenomenon in remote sensing. The figure below shows the expected change in reflectance of green leaves under ...
6
votes
2answers
133 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?
6
votes
1answer
367 views

How to remove clouds in High resolution Imagery(.5 mGeoeye)

i have imagery with high resolution .5m, large parts covered with clouds,so it's obscure many urban areas. thank you.
6
votes
3answers
301 views

Is it possible to automate the 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 their research or documentation that supports a specific ...
6
votes
3answers
297 views

Python resource for remote sensing?

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 ...
6
votes
3answers
184 views

Classifying small structure in water using IR band

I was wondering how to identify small structures (eg. beacons) in a water body. I have worked with RGB images and its almost impossible to classify waterbodies in these images. How does IR band help ...
6
votes
1answer
167 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 ...
6
votes
2answers
827 views

Transform SPOT5 images to natural color images

We're currently using PixelSense to convert raw SPOT5 images to natural color ones for display and printing. Do you know a good algorithm to perform the same task as we want to ingest raw images in an ...
6
votes
2answers
671 views

Imagery Database/Metadata Store

I'm a Remote Sensing PhD student, and as such I have a large number of satellite images that I'm working with. I'm starting to fail to keep track of them all and I have a lot of metadata that I want ...
6
votes
1answer
363 views

Methods of cloud shadow detection for Landsat data?

Detecting clouds doesn't seem to be much of a problem, rather the challenge is in selecting cloud-shadow classes that don't also include coastal areas, agriculture, etc. For a project I'm working on, ...