Questions tagged [remote-sensing]

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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3answers
2k views

How to process Sentinel-2 data from AWS

Sentinel-2 imagery granules downloaded from AWS archives (http://sentinel-pds.s3-website.eu-central-1.amazonaws.com) have a little different data structure than the original granule sub-folders of ESA ...
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4answers
883 views

What satellite imagery would help to show spring locations?

I've got lots of tiny streams on a hydrography shapefile. Historic texts indicate that certain ones have headwaters at "sources" or springs, and I want to try to find these. Browsing the historical ...
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2answers
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What is NIR LiDAR?

Can LiDAR sensors collect near-infrared (NIR) data at the same time or does there need to be a separate NIR camera that is combined with the LiDAR data after collection? Blue Marble makes reference ...
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2answers
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How do I deal with tiles in the Orfeo Toolbox segmentation?

I'm using the Orfeo Toolbox for segementation of large Very High Resolution Satellite images. It performs very well and i'm mostly very happy with it. But I still get some weird/bad results that I ...
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1answer
6k views

the difference between pattern recognition and image classification in remote sensing? [closed]

Does anyone know the difference between pattern recognition and image classification?
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3answers
390 views

Matching Landsat 8 with previous Landsat images

I am working with Landsat 8 in ENVI. My image's dimensions are 8921 x 13131. I need to apply a forest mask to this image with dimensions of 8805 x 12321. I try to resize an image, but it doesn't work. ...
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7answers
9k views

Failed to create signature file

I've no clue how to solve this issue in 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 says in the exercise. I ...
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2answers
906 views

LANDSAT Image classification and open source solution(s)

I have some experience with ERDAS IMAGINE in doing some supervised/unsupervised LANDSAT imagery classifications and now find myself in the position of needing to do the same but without the access to ...
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3answers
859 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.
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1answer
201 views

How to interpret MOD44B 8-bit quality layer

I have 15 annual MOD44B (vegetation continuous field) HDFs for 2000-2014, working in Arcmap 10.2. Each contains several bands. The two I'm concerned with are "percent tree cover" and "quality." The ...
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1answer
192 views

Understanding measurement units for MODIS data?

I am working on MODIS data in ESA SNAP, specifically the Terra sensor, and I'm having a hard time understanding the unit of measurement of the data provided. I have downloaded Level 1B data (...
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1answer
980 views

How to automatically check for lidar flight line overlaps?

I have a series of lidar-based raster products created via FUSION. Since I am working with low density lidar data, many of the raster images show significant striping where lidar returns overlap on ...
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1answer
256 views

Sun glints and landsat 8 surface reflectance product

I was wondering if the Landsat 8 surface reflectance product needs to be corrected for sun glints if I want to use it for atmospheric correction over water surfaces. I'm actually working on ...
5
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1answer
142 views

Is it possible, and if so how, to effectively classify vegetation types using false near infra red imagery?

Background : I use near infra-red imagery to delineate wetlands and water bodies with good success. It's also obvious to distinguish between new healthy vegetation and older growth and land areas with ...
5
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1answer
291 views

Accuracy Assessment for single date classification - possible to apply to classification without reference images?

I applied supervised maximum likelihood classification to a yearly stack of Landsat images (resolution 30m). The land cover classes are related to coniferous forest, i.e., forest, clear-cut, fire, ...
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2answers
343 views

Pattern search in satellite imagery

I would like to search for the specific buildings (polyhouse in my case) on the map like the one shown here Are there any free options available which can give me lat and lng of such shapes/features ...
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1answer
490 views

Sentinel 2 Tool Box on Commandline

Has anyone tried to use the Sentinel toolbox in command-line? I have downloaded the SNAP tool and installed on a Ubuntu workstation and the GUI works well. I now want to want to use it in a command-...
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1answer
493 views

Why does the peak of a mountain appear bright on Radar images?

Why does the top of a mountain appear bright on a SAR (radar) image. I know that the peak of a mountain is subject to a layover effect, thus appearing closer on the radar image than the bottom part of ...
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1answer
344 views

Using remote sensing satellite for chlorophyll mapping?

Location of my research are reservoirs which have an area of 47 and 62 km2. I need a better image resolution than Landsat(Pan).
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1answer
488 views

MCD43A3 MODIS products

I have MCD43A3 product and I am using that to get the albedo values(Black sky and White Sky). I have some in-situ snow depth data, corresponding to which I want to get these albedo values. For most ...
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1answer
711 views

Detect cattle on high resolution satellite images

I have no deep experience in remote sensing. I would like to know if it might be feasible to detect cattle (i.e. a single cow or bull) from a high resolution satellite image e.g. Worldview 3 with a ...
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1answer
275 views

How to classify different surfaces having almost similar Reflectance responses?

I am using ENVI 5.3 to classify a Region of Interest clipped from Landsat 8 OLI. I have already performed calibration of my DNs by transforming it into Radiance and derived Reflectance image using ...
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1answer
350 views

Loop NDVI calculations for hyperspectral datacubes in R

I am writing a script for the processing of different hyperspectral datacubes. The datacubes contain flight lines that I've recorded with a UAV. In total there are 10 flight lines that need to be ...
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1answer
117 views

What's this line in Landsat MSS image?

I have a Landsat MSS image file that contains a vertical string of incorrect pixels. Does anybody know what this might be?
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2answers
1k views

Resolving Sentinel-1 Interferogram Unwrapping error when constructing DEM/DSM?

I have been trying to create a DSM of a coast and some islands, and have run into some issues regarding how the data looks in the unwrapped interferogram (which affects my height data). I have been ...
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1answer
394 views

Using original Landsat multispectral image or pan-sharpened image in land cover classification?

I am currently creating land cover maps of a number of national parks across Asia from Landsat 8 imagery and also later from SPOT imagery. I plan to use supervised classifications in ERDAS IMAGINE and ...
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1answer
470 views

Atmospheric Correction Model Output for Landsat 8 Image?

Following are my procedure, observation and question/ request: Data Source: Earth Explorer Landsat 8 Grass GIS Version: 7.0.2 RC1 Windows 7 32 bit OS I have been trying to conduct an Atmospheric ...
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3answers
230 views

Can a satellite go over the same area in different passes overtime

Can a sun-synchronous satellite (let's consider Sentinel-1) go over the same place, one time in an ascending pass and the next time (or few times after) in a descending pass?
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2answers
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How to compute NDSI in ArcGIS for Desktop?

How do I compute a Normalized Difference Snow Index (NDSI) in ArcGIS's Raster Calculator? I have a Landsat 8 scene (hdf4 format) that contains derived surface reflectance band-by-band. Each band is a ...
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1answer
342 views

Remote Sensing Indices for urban expansion

Apart from NDBI, could you name a few indices for urban expansion? I have done some search on google but haven't found anything that could help me. Perhaps, What I'm interested is also: road/...
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2answers
949 views

Applying pixel reliability mask to time series MOD13Q1

I am working with a 23-band GEOTiff in which each band is a 16-day MVC MODIS NDVI image. The MODIS .hdfs include a "pixel reliability" image with the following values: [-1]: Fill/No Data-Not ...
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1answer
497 views

EVI coefficient values for Sentinel 2 image analysis

I am estimating EVI for Sentinel imagery and wanted to know the values of the coefficients L, C1, C2 etc. All the literature I have found use values from MODIS.
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0answers
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Single Tree detection in ArcMap? [closed]

I was wondering how I could extract "crown area" of single trees in a forest from a high-resolution image with only 3 band (RGB) in ArcMap. ( No NIR to use NDVI as any threshold). I need a fast easy-...
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6answers
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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!
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2answers
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Why is short-wave infrared portion of electromagnetic spectrum so sensitive to fire?

After attending a remote sensing workshop and using Copernicus data to monitor natural disaster scenarios, my question could not be fully answered by the instructor. All that was said, was that is in ...
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6answers
5k 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?
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2answers
556 views

Why use feature extraction?

Why is feature extraction important? Why do we have to reduce the feature space? Is it only a computational problem when we use hyperspectral imagery or does this procedure improve the ...
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3answers
1k views

Defining landuse from remote sensing data? [closed]

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 ...
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2answers
1k views

Satellites to retrieve UV bands

I want to retrieve some satellite images with UV bands, but I don't know which satellites are providing UV bands and whether we can freely download them. I have already downloaded Modis and Landsat ...
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1answer
510 views

Landsat images with bad quality

I downloaded several Landsat images from some years between 1985 and 2014, all of them with good quality. Nevertheless the period from 2003 to 2013 is not worth it. I checked all images. Most of the ...
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2answers
3k 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 ...
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3answers
1k views

Download MODIS/MCD19A2 AOD product with R

I'm looking for a programmatic way to download MODIS/MCD19A2 AOD data in R. So far, I've found a pretty solid R package called MODISTools that works nicely with the MODIS/VIIRS RESTful API. However, ...
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2answers
69 views

No Landsat across northern Australia in 1974-1977

Why there is no Landsat imagery available for the Gulf of Carpentaria, northern Australia, in 1974-1977? I have obtained imagery via USGS Earth Explorer from 1972 through to 2017, but there is a gap ...
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3answers
306 views

Estimating vegetation composition from digital images

I am running a Master's project researching Greater prairie-chicken nest and brood survival. Some of my intended covariates include local vegetation measures using digital imagery. I would like to use ...
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2answers
2k views

Detecting cloud shadows

I am trying to detect cloud shadows in Landsat images. I came up with producing good shadows and cloud masks. Now I'd like to implement my cloud mask adding cloud shadows. Do You have a good idea to ...
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2answers
3k views

How to calculate LAI (Leaf Area Index) using Remote Sensing? [closed]

I am new in remote sensing, and I would like to ask the community what are some good methods to calculate the Leaf Area Index (LAI) using Remote Sensing Data, for agriculture mostly applications.
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2answers
2k views

Classify forest with NDVI from Landsat 8 and 7

I'd like to calculate the NDVI for multi-date satellite images of Landsat (7,8) to perform a change detection on the deforestation of the Amazon rainforest. I already acquired surface reflectance ...
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3answers
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What should come first-Radiometric calibration or co-registration?

For a pair of images,in the pre-processing of satellite images, which step should come first- Radiometric calibration or co-registration?
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4answers
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Where to download 4-band NAIP imagery for California?

I've been trying to find orthoimages with 4 bands for a couple of counties in California. I managed to download some from the GeoSpatial Data Gateway from the USDA (NRCS), but they all only have 3 ...
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2answers
447 views

Zooming into landsat-8 produces pixellated view

I am working on a project were I am using LANDSAT 8 images for remote sensing. The issue that I have is that when I zoom into them the photo is pixellated. I can not see a thing. When I zoom out ...

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