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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1answer
138 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
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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
300 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
999 views

Net Primary production (NPP) calculation

When I calculate Net primary production (NPP) for a local scale, what kind of software should I use? I always use ENVI, ERDAS, ARCGIS and IDRISI. Is it possible to use these programs for NPP ...
3
votes
1answer
270 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
700 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
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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
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2answers
483 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
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6answers
575 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
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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
404 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 ...
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3answers
1k views

Reading BSQ file format

is there a way to open BSQ file format in IDL? thanks in advance.
6
votes
2answers
613 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
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2answers
726 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 ...
0
votes
0answers
572 views

buildings shadow areas calculation

is it possible to calculate shadow areas of buildings or simulate shadows of buildings in a city using e-cognition software, with the DSM of the buildings and the sun angle and azimuth known?....if ...
3
votes
6answers
2k views

shadow simulation from buildings

is it possible to use hillshade function in ArcMap to calculate shadow areas of buildings or simulate shadows of buildings, using DSM of the buildings and the sun angle and azimuth?
19
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9answers
3k 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?
5
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3answers
665 views

ENVI EX reviews?

Does anyone have a review of ENVI EX? I am wondering how well the Feature Extraction and Image Classification workflows function.
13
votes
8answers
977 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 ...
9
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6answers
462 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 ...
5
votes
2answers
435 views

Disaggregating aggregate GIS data using remote sensing

I haven't really done much with remote sensing imagery. I have census data for an area, and a TIFF raster image of the area. I'm sure this is possible, is there a simple way to disaggregate the ...
18
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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 ...
12
votes
4answers
4k 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?