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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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 ...
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?
4
votes
5answers
2k views

Extracting tree crown areas from remote sensing data (visual images and LiDAR)

I am looking for a method to process a remote sensing image and extract the crown areas of the individual trees from the image. I have both visual wavelength areal imagery, and lidar data from the ...
21
votes
5answers
6k 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. ...
22
votes
12answers
14k 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 ...
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 ...
25
votes
7answers
4k 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 ...
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, ...
4
votes
1answer
3k 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 ...
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 ...
5
votes
2answers
3k 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 ...
4
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 ...
8
votes
2answers
2k 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.
2
votes
1answer
2k 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
2answers
106 views

How to remove bounding box extents based on reflectance values of the image of Landsat8 by using R programming

I have taken the reflectance image from Landsat8 bands. Now the extents of bounding box showing negative values , to proceed to my next level of the process i need to remove this negative values and ...
-2
votes
1answer
205 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
3answers
4k 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 ...
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 ...
3
votes
1answer
583 views

Random-Forest Classification of 10cm Imagery for species-distribution in R (no point-shapes)

I'm actually trying to classify 10cm-resolution images with the RF-package. I do this to separate some species in the forest, seen on my images. While I was searching for an answer, I found the ...
4
votes
1answer
573 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
1answer
287 views

Difference Between Radiometric calibration and radiometric correction

I am new in remote sensing field. I sometimes got confused when I read about image pre-processing. Can someone please elaborate to me the difference and some example methods to do radiometric ...
2
votes
1answer
131 views

Incorporating terrain data to predict canopy cover using randomForest in R

This is a subjective question. Thank you bearing with me. I have a 5.8 m resolution satellite image (LISS IV by IRS-P6, in bands 4, 3 and 2) of a densely forested region in the Eastern Himalayas. My ...
4
votes
2answers
167 views

Why does the resolution decrease with increasing incidence angle in the Sentinel-1 SAR sattelite

On this link (Sentinel1 webpage for a SLC product), the resolution is written as a range from the highest corresponding to low incidence angle, to the lowest resolution corresponding to high incidence ...
4
votes
1answer
492 views

How can I parse modis MOD13Q1 quality layers in R?

I'd like to parse MOD13Q1 VI quality layers in R. My original code must have been incorrect, because it gave lots of "deep ocean" flags in the middle of Brazil. After the changes suggested by ...
4
votes
2answers
2k 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 ...
2
votes
5answers
3k views

Fix Landsat 7 SLC-off in ENVI?

I have a couple of Landsat 7 images and they all have striping as a result of the SLC failure. Does anyone have any suggestions as to how to destripe the image using ENVI? I plan to use these images ...
4
votes
1answer
731 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 ...
3
votes
2answers
136 views

Is SRTM 3 second arc free of non-terrain features?

I made an elevation map of my study area in Macapa, Brazil. But the region has the average elevation lesser than 30 m as I can see from my map derived from SRTM 3 second arc. According to my ...
2
votes
2answers
2k views

Converting *.tif file into headerless (flat) binary file?

I am using NDVI files (value range -1 to +1) created from Landsat CDR images to produce a timeseries in TIMESAT software. My .tif file has following characteristics. File type TIFF,Data Type ...
1
vote
2answers
305 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 ...
1
vote
2answers
773 views

LANDSAT 8 i.landsat.toar error GRASS 7

I am a bit new to GRASS, but I have managed to get a lot of good work done thus far. However, the following error is really throwing me off, because I can't find any help anywhere for it. I am using ...
14
votes
3answers
787 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 ...
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 ...
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 ...
6
votes
2answers
6k views

Landsat in ArcGIS

I need to learn how to download, import and compose Landsat 8 in ArcGIS for natural colors (preferably in a GEOTIFF format). I have tried on my own but it seems that I am doing something wrong... can ...
5
votes
2answers
2k views

Are there Python packages for Landsat 8 processing?

While there are a number of python projects for MODIS acquisition and processing (pyModis and get_modis), I have yet to encounter a toolset for automating Landsat 8 processing in Python. There's ...
6
votes
2answers
312 views

Landsat8 DN to TOA Reflectance (minus values)

I'm learning how to perform atmospheric correction manually, hence not using the automated methods available in ENVI metadata (band 1) for my Landsat 8 scene is as follows; RADIANCE_MULT_BAND_1 = ...
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 ...
0
votes
2answers
2k views

how i calculate land surface temperature using landsat 8 in Envi 5.1

I am doing research about land surface temperature using Landsat 8 image. However, I have a problem with them. I have read document from Landsat.org, but i can not do it in Envi. Could you help me ...
4
votes
2answers
132 views

How to correctly parse MODIS QA layers?

I'd like to correctly parse the MOD13Q1 VI Quality layer (see Table 2 in "layers" here). For this, I'm trying to follow Example 1 from this tutorial (page 10). I'll illustrate my problem with a pixel ...
4
votes
2answers
158 views

“Official” definition to hyperspectral sensor

I was checking in the literature about a formal definition for hyperspectral sensors, and the most complete definition I found was from The Center of Space Research (@ University of Texas in Austin): ...
4
votes
6answers
3k views

shadow simulation from buildings [duplicate]

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?
3
votes
1answer
335 views

Is atmospheric correction necessary when working with multi-spectral indexes?

When you are working with Landsat Level 1 data and calculate indexes, e.g. NDVI, NDBI, SAVI ..., do you calculate them using raw data (pixel DN value), or atmospherically corrected data (surface ...
3
votes
3answers
4k views

Download high res NDVI imagery

I'm trying to find a good source of NDVI imagery, but I'm struggling to find proper high res imagery, particularly for northern Europe. Does anyone have references to high res imagery, that is ...
3
votes
3answers
717 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
4answers
878 views

Some remote sensing tutorials [closed]

I could use some tutorials on remote sensing, but some books provided they are free, would be useful. To be specific, tutorials on ERDAS Imagine, ENVI and other remote sensing software, general ...
3
votes
2answers
2k views

Figuring out map scale when you know the spatial resolution of a Satellite Image?

I'm interested in figuring out how map scale and satellite pixel size (spatial resolution) are related. For example the TM or ETM+ has roughly 30m ground resolution, then, what could be the finest ...
3
votes
3answers
3k views

Where to download 4 band NAIP imagery?

I seem to recall USGS Earthexplorer providing current and historic 4 band NAIP imagery over the last few years. It appears that these data have been migrated to the National Map. However, the ...
0
votes
3answers
234 views

Automated Forest Change Detection

Using two different time of images in the same places. Can i develop an automated change detection for forest area? What / which are the suitable software to used?
9
votes
1answer
488 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 ...