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.

learn more… | top users | synonyms

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 ...
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?
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 ...
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 ...
4
votes
1answer
1k views

Open Source Alternatives to ERDAS IMAGINE ATCOR?

I have been using ERDAS IMAGINE's ATCOR extension for ATmospheric CORrection of ASTER imagery. What opensource options exist for atmospheric correction of ASTER Level 1B products? I'm primarily ...
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 ...
3
votes
2answers
2k views

Open source solutions for Landsat-8 mosaicing and correction?

I am familiar with the major commercial remote sensing packages (ENVI, IDRISI ERDAS, etc), but I haven't previously had the opportunity to utilize open-source solutions. I have a several new ...
-2
votes
1answer
108 views

MODIS LST 8 days data to have 16 days LST? [closed]

can i combinate two parameters with different Temporal Granularity , i mean can i combinate image LST MODIS 8 days with image NDVI modis 16 days??
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?
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, ...
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. ...
4
votes
1answer
453 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 ...
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 ...
4
votes
1answer
324 views

Estimating Landsat 7 azimuth (heading)

I am trying to understand if the Landsat 7 satellite ETM+ orbit has any significant azimuth or if it could be assumed as 0° (as it is not a pointable sensor). I searched in the web but could not find ...
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 ...
14
votes
3answers
633 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
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 ...
7
votes
2answers
736 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 ...
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 ...
3
votes
3answers
377 views

How to extract surface from air photo avoiding trees and buildings?

I am working with Drone air images. These are geotiff images and clearly portray trees and buildings. I need to first classify the image according to land cover distribution, then need to remove the ...
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?
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
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 ...
4
votes
2answers
376 views

Best Landsat-5 TM band combination for detecting fire scars

I am looking for the best band combination with Landsat 5 imagery to detect fire scars.
3
votes
1answer
1k 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 ...
2
votes
1answer
397 views

Failed to create signature file

I need some help, because I've no clue how solve this issue the exercise that I'm trying to perform. The point where I'm stuck is 4. "Create signature file as LandsatCompS.sgs". I've done what it ...
2
votes
1answer
245 views

I need some more information on ASTER for time series analysis

See my previous post on ASTER I have a question about that I am not sure about. So, if I wanted to analyze 10 years or so, do I need to download each ASTER file for each year (e.g. 2003 ASTER, 2004 ...
2
votes
2answers
226 views

MODIS Level 1B batch process

I am a new MODIS Level 1B user. I have been using the MODIS Swath tool to process my images. However, I have over 1000 images to process. I was wondering if there a script available in IDL or R (very ...
1
vote
0answers
69 views

How to Normalize or rescale the NDVI raster image

I have processed my landsat band 3 and band 4 of different years to derive NDVI values the possible values of Normalized difference vegetation index is -1.0 to +1.0. The bands were atmospherically ...
1
vote
1answer
743 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 ...
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 ...
1
vote
2answers
100 views

How to find the minimum pixel value within a region of interest?

I am working on a Python script for dark object subtraction, a radiometric correction method for remotely sensed data.To accomplish this, I need to find the minimum band pixel value of a waterbody ...
0
votes
1answer
158 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?