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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5
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2answers
2k 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
4
votes
2answers
160 views

What Information Does the Blue Band Provide?

I am playing around with ERDAS and was implementing image difference on two rasters separated by interval of time. I was using a blue band raster and I created a default threshold for percentage ...
0
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1answer
134 views

MODIS LDOPE mask_sds Error

I am using the LDOPE mask_sds tool to mask a MODIS image based on the quality flags for MOD13A3 NDVI. The full command that I am using is: mask_sds -of=mask.hdf -fill=-3000 -sds='1km monthly NDVI' ...
6
votes
1answer
344 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.
8
votes
4answers
670 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 ...
19
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5answers
2k 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. ...
7
votes
5answers
626 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?
0
votes
1answer
667 views

MRT (MODIS Reprojection Tool) input error

This is my first time to use Modis Swath Tool to deal with images. I've downloaded 4 MOD44B granules (using the FTP script method), and am trying to use MRT to mosaic them. When I add the 2 files I ...
5
votes
1answer
1k 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 ...
9
votes
2answers
235 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, ...
4
votes
1answer
434 views

Statistical analyses for survey against raster?

I am somewhat of a newbie to geostatistical analyses, but pretty familiar with GIS and remote sensing packages. I was wondering if anyone had suggestions on appropriate geostatistical analyses for a ...
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 ...
14
votes
3answers
629 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 ...
3
votes
2answers
594 views

How to convert Landsat L1G raster to Geotiff?

Is it possible to convert a Landsat L1G raster file like L71001070_07020000728_B30.L1G to Geotiff using free software?
4
votes
1answer
89 views

What proportion of the 240m area sensed by MODIS must be forest before it is defined as forest?

MOD12 is a MODIS product at 240m resolution. Landsat produces 30m resolution products, which I resampled to 240m resulting in a raster of proportion forest cover in each 240m pixel (based on the mean ...
6
votes
0answers
380 views

Land Classification with Spectral Python (SPy) [closed]

Does anyone have experience working with the Spectral Python module for land classification? The following k-means clustering example takes an iterative approach to classification through pixel ...
14
votes
3answers
608 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 ...
5
votes
2answers
2k views

Moisture Interpretation from Landsat Images

I am working on a "land suitability for crop" project. Can anyone let me know how to get any type of information which can be related to moisture index of soil? I have Landsat 5 data with band 3 and ...
1
vote
1answer
113 views

Dicing large mosaics

What is the best way to take a large mosaiced raster dataset (e.g. from http://viewer.nationalmap.gov/viewer/) and tile it to USGS 3.75 minute quarter quad specs? The problem I am having is creating ...
2
votes
1answer
124 views

Applications and methods for TerraSAR X

People who already used or are familiar with TerraSAR X, can you point out: Main applications and methods Opensource software tools Thanks
3
votes
1answer
406 views

How to use a spectral library

I want to classify an Aster image using the ASTER Spectral Library - Version 2.0 Anyone here ever done this? Any suggestions? Note: I'm using opensource GIS and Remote Sensing software Thanks.
0
votes
2answers
212 views

Remote sensing: How to start with interferometry?

I need to start learning about the interferometry techniques available/used for remote sensing data (radar or optical). Which are the main applications? Which techniques are applied? Which Earth ...
2
votes
1answer
170 views

Sandbars feature extraction from satellite image

I want to know if we can analyse the permanancy of sandbars from a satellite image? Whether the formation of the sandbar is permanent or temporary.
3
votes
1answer
316 views

Cloud and Snow Differentiation

I am doing unsupervised classification of a mountaneous terrain and I have used 500 classes to classify the land use. In my result, cloud and the snow are categorized in the same class. How do I ...
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 ...
4
votes
3answers
597 views

Remote sensing: How to define landuse from remote sensing data?

I am trying to research ways into obtaining landuse data for a project which calculates the visual impacts of wind parks. I have a DEM and DOPs for a relatively large region (5000km²), but I have no ...
2
votes
1answer
742 views

How to make a cloud mask from a daily MOD09 image?

I'm currently working with MODIS data and i've been having some trouble with several aspects of the steps I need to take. For example, I need to make a cloud mask from a daily MOD09GQK image, and i'm ...
4
votes
6answers
792 views

Looking for free DEM and other remote sensing data for Germany

Does anyone know of any sources for free DEM and other remote sensing data in Germany? I don´t think Europe is as open as the USA when it comes to free data!
2
votes
2answers
136 views

What exactly is 'anti-aliased image generation'?

I tried to google it, but didn't quite get it. Any help and/or examples? Thank you!
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 ...
2
votes
1answer
801 views

QGIS and satellite images band combination

When I add a satellite images as a raster in QGIS: 1. Why the image is changed, it looks like it has only one band?; 2. where is a tool for band combination? Thanks!
14
votes
7answers
625 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 ...
11
votes
1answer
632 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 ...
4
votes
2answers
147 views

Remote sensing software options for creating structure footprints from aerials

As shown in screen shot here, just wondering what other software options for creating polygons based on structure footprints are available. Something cheaper than ENVI but still versatile would be ...
10
votes
1answer
576 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 ...
7
votes
1answer
391 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
5answers
237 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 ...
0
votes
1answer
147 views

Problem running i.gensigset in Grass. Any ideas?

It just returns ERROR: Unable to create signature file. It doesn't say why... Anyone had this before and found a solution?
3
votes
3answers
1k views

Problem with NDVI image value

I'm really happy to find this website. It is very helpful for the learners of Arcgis. Now I wanna ask a question. When i open NDVI image in ENVI, its value is still within the range (-1 to 1). But ...
3
votes
1answer
315 views

To determine phenological events based on Greatest increase NDVI appraoch

I have a problem with a phenological study. The study area is in temperate zone of Asia. I have been doing phenological research using MOD VI product. I wanted to extract phenological events ...
4
votes
2answers
1k views

Calculating Net Primary Production (NPP)?

When I calculate Net primary production (NPP) for a local scale, what kind of software should I use? I always use ENVI, ERDAS IMAGINE, ArcGIS for Desktop and IDRISI. Is it possible to use these ...
3
votes
1answer
288 views

About FAPAR calculation

I want to calculate FAPAR in different land cover types using max and min value of NDVI. I have a raster image with 9 Land cover types and max, min value of NDVI in each land cover type. But I don't ...
10
votes
2answers
748 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 ...
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 ...
11
votes
2answers
502 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?
17
votes
6answers
621 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 ...
13
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, ...
3
votes
1answer
422 views

Slope, aspect and beam in R.Sun (GRASS)

I'm starting to mess about with the solar radiation packages of GRASS and ArcGIS and have become rather stuck on the GRASS side of matters. I have a DSM area, and that is feeding into GRASS well ...
1
vote
3answers
1k views

Reading BSQ file format

is there a way to open BSQ file format in IDL? thanks in advance.
6
votes
2answers
656 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 ...