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

5
votes
1answer
60 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 ...
0
votes
1answer
15 views

Rectifying a Tiff Given One Corner Coordinate

I'm trying to rectify an image that I don't know much about other than the coordinate of the southwest corner, which I was able to pull using ExifTool. Is there any programming solution to ...
2
votes
0answers
51 views

16-day-MODIS NDVI values seem to be wrong compared to my soil moisture ground data!

I'm using MOD13Q1 product of MODIS for estimation soil moisture. As I know, this product is made up of the maximum value of NDVI of each pixel over 16-day calculated NDVI values. The problem is that ...
3
votes
2answers
64 views

Atmospheric correction of Landsat images

In satellite imagery, isn't cloud removal supposed to be performed while atmospheric correction? My question arises from the fact that even though these Landsat images are atmospherically corrected, ...
1
vote
1answer
37 views

stack 10 modis ndvi geotiffs and scale them by 0.0001

I have 10 geotiffs Modis ndvi named 2005.tif ... 2014.tif I want to stack them all and create timeseries. i know how to do that, but the stacked images still need scaling by 0.0001. how can i bulk ...
1
vote
0answers
26 views

qgis Semi automatic classification pluggin how to add text to rows in attribute table

I want to use a previously created shapefile as Training shapefile in the semi automatic cassification pluggin. Therefore i added 4 fields to this shapefile: Macro_ID (int), MCl_info (text), Class_ID ...
0
votes
0answers
26 views

Radiance values of T-cap in ERDAS

I have applied USGS Defined method for Gap filling for Landsat ETM+ data. After i have to apply T-cap... but when i check its spectral properties in ERDAS, it shows slight different values in Radiance ...
3
votes
1answer
37 views

Is a photo of an infrared slide taken in a light box a digital Infrared image?

Many years ago we received many aerial infrared images. They were developed on transparent film like a slide but much bigger - 20cm x 35cm. If I now take a digital photo of these images, are they real ...
1
vote
2answers
63 views

Improves performance on R working with raster files

I´m trying this code to look for NA and negative pixel values and replace it for 0. But it´s too slow. Any tip for improve the performance of it? "all.files" is a list of address of the images. "r1" ...
2
votes
1answer
63 views

How to calculate the Scattering Matrix for a Sentinel-1 image

How can we calculate the elements of the scattering matrix (Spq with p and q being the transmit/receive polarizations), for a Sentinel-1 image? Does the image have to be in a Single-Look Complex ...
2
votes
0answers
70 views

Calculating Aerosol optical thickness from Landsat 7

EDIT I have added question down I am reading one paper and I found method to retrive AOT from landsat 7 image This should be simplifield equation, because they assumed observation zenit as 0. Than ...
0
votes
1answer
75 views

how to calculate summary statistics and produce line plot for daily MODIS LST quality bands

I have a raster stack (numpy 3d array) of daily MODIS LST quality bands. The quality bands have pixel values that correspond to the quality of the LST data in each pixel. For example, 2 = no data ...
0
votes
0answers
37 views

Accuracy assessment in change detection (satellite imagery)

What are some methods for assessing the accuracy of change detection, when performed on satellite images? From whatever study I have done so far, comparison with ground truth is suggested but mostly ...
1
vote
0answers
38 views

How to extact very narrow water linear features from GeoEye-1 image

I need to extract beaver channels from a GeoEye image (attached image). What is the best approach to automatically delineate such very narrow and not very sharp water features?
3
votes
2answers
149 views

Sentinel-2A: Begin of operational period?

This also might be of interest here, as it is an important data source: When does Sentinel-2A finally become operational and deliver images regularly? I tried to find information on that, but ...
6
votes
2answers
208 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 = ...
1
vote
2answers
45 views

i.landsat.toar not working and returning error [duplicate]

First time using grass. I need to convert DN to reflectance. Imagery -> Sat. images tools-> i.landsat.toar. But when I add raster name. I get error. Im using landsat 8 images WARNING: WARNING: ESUN ...
0
votes
1answer
51 views

Fractal Net Evolution Approach (FNEA) Citation

I've been looking for some original source to cite for FNEA (Fractal Net Evolution Approach), instead of just citing eCognition. Does anyone know of a paper on the origin of FNEA? My searches just ...
3
votes
1answer
222 views

SAR - Using the Intensity or the Amplitude for the classification

In a Sentinel-1 Level 1 Ground Range Detected SAR data product, Intensity = Amplitude * Amplitude. Should the intensity image or the amplitude image be used for radiometric calibration when using ...
2
votes
1answer
117 views

Is possible to merge landsat 8 with High Resolution Satellite Imagery?

i have landsat8 and High Resolution Imagery (1m) in the same study area, is possible to merge them to get one imagery so that i can take advantage of the accuracy satellite imagery.
2
votes
3answers
116 views

Search and concatenate Landsat bands with Python

I have a number of Landsat geotiff (*.TIF) file in a folder. The problem is simple, I need to search certain Landsat bands from that list and make a composite tif image. I am using Orfeo Toolbox's ...
7
votes
2answers
298 views

How to download MOD16 (Modis Evapotranspiration) image?

I use a 'R' script for downloading MODIS imageries. However, it doesn't give MOD16 product. I could neither find the MOD16 product in earthexplorer website. Though the desired product is available at ...
0
votes
0answers
43 views

Pan sharpening of World View 2 image

I want to pan sharp world view 2 multispectral data its panchromatic band using HCS resolution merge tool in erdas imagine, can any one guide about which resampling technique(Nearest neighbour, ...
2
votes
0answers
65 views

GIS or Remote Sensing technique to map sub-surface features?

I am trying to delineate agriculture tile drainage in Midwest. Does anyone know of any GIS and/or sub-surface remote sensing techniques to detect tiles/objects buried in shallow depth of soil? Does ...
3
votes
2answers
98 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 ...
0
votes
0answers
20 views

Image ID Landsat8 in SCP plugin

I have tried to classify the land with SCP plugins. how do I get IMAGE ID in LANDSAT8 as in the image below. Thank you for your help and advice.
0
votes
1answer
114 views

Calculate NDVI with converted canon sx260 hs

I have converted my canon sx260 hs so it can capture NIR part of specter. Can anyone tell me how can i calculate NDVI now? My guess is that on the blue channel is now NIR value and Green ...
2
votes
1answer
92 views

How to handle MOD13Q1 NDVI Product Quality Assessment(QA) flags?

I am working on MOD13Q1 NDVI Product and i want to apply Savitzky Golay filter for smoothing Ndvi time series using Quality Assessment(QA) flags. I studied MOD13Q1 NDVI help file and found that ...
3
votes
1answer
64 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 ...
2
votes
1answer
45 views

Rigorous geometrical models for InSAR imagery?

I'm looking for rigorous geometrical models for InSAR imagery. I'm familiar with the rigorous models for SAR images, but I don't know the model for InSAR. I searched through the internet, but I didn't ...
3
votes
3answers
223 views

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?
1
vote
1answer
84 views

Enhanced Vegetation Index Value

Can enhanced vegetation index have values greater than 1? I am using the ENVI software to calculate enhanced vegetation index (EVI) of a hyperspectral image and my EVI value range was from 0 to 1.9. ...
3
votes
3answers
84 views

Multi Temporal Images

I am new to remote sensing, so I would want to clarify my understanding of the meaning of Multi Temporal Images. As far as I understand, multi temporal images are multiple images of the same scene ...
1
vote
0answers
79 views

Format of SAR images

What is the format in which SAR images are stored? By format I mean when a SAR captures an image, it gets saved in what format? jpg? png? tiff? or there is some other special format? Is there a ...
0
votes
0answers
36 views

How to get multi-temporal InSAR data?

I am very much new to InSAR data. At the moment, i'm stuck at this website https://ursa.asfdaac.alaska.edu. Just wanna know, is it possible to get multi-temporal InSAR data for a particular region ...
3
votes
1answer
72 views

what does it mean to store cross products in SAR product data file?

I'm reading the UAVSAR data format For definition of two types of file we have: MLC files (.mlc): calibrated multi-looked cross products, floating point format, three files8 bytes per pixel, ...
3
votes
1answer
136 views

What is multilooking?

Today I found a video on youtube for multilooking the data with NEST (Next ESA SAR Toolbox) and it seems that it produces square pixel out of rectangular SAR pixels. Does it operate as simply as ...
2
votes
2answers
209 views

Deciding variables for unsupervised image classification?

The results of an unsupervised image classification may vary A LOT depending on the variables you use from the beginning. These are the variables for the tool in ArcGIS:number of classes, minimum ...
0
votes
1answer
48 views

aerosol optical depth

i want to extract aerosol optical depth on land using modis it seems like I need a value from one of these parameters between Corrected_Optical_Depth_Land and Corrected_Optical_Depth_Land_wav2pl but ...
6
votes
1answer
125 views

Free open satellite or other remote sensing data for night time?

I usually work with daytime satellite images to do some image classification (mostly Landsat data from the USGS EarthExplorer). Right now I'd like to check at some night time images to work on city ...
2
votes
1answer
230 views

Calculating NDWI in Erdas IMAGINE 2014

I'm using MOD09GQ product of MODIS to calculate vegetation indices in Erdas 2014, and I was able to extract NDVI using Erdas Model Builder. What is the formula I should use in model builder for ...
0
votes
0answers
25 views

Problem using ENVI/IDL ENVITask('BuildBandStack')

I am trying to stack 2 bands together from 2 different landsat images using ENVITask('BuildBandStack'). These are landsat images from two different years, and Band 1 in both years. When I run my code ...
1
vote
0answers
48 views

Hard wood tree and Soft wood(shrubs) Vegetation Differentiaton

How I Differentiate Hard wood tree (like Mango, Sal) and Soft wood(shrubs like reed) Vegetation using Multispectral or Hyperspectral Image? I have TM, ETM, OLI, Hyperion, Aster Image and ERDAS 2011, ...
0
votes
1answer
106 views

Is there any packages to download landsat image by shapefile boundary in R or python? [closed]

I want to find a package which can automatically download images within a predefined administration boundary (shapefile format). Does anyone know a package can conduct or simplify the process?
1
vote
1answer
221 views

Why is azimuth resolution worse than range resolution in Sentinel1 (SAR) [duplicate]

Why is the azimuth resolution in Sentinel (SAR sensor) worse than the range resolution? The table in this link gives the resolution for SLC products aquired in the different aquisition modes. In ...
0
votes
1answer
55 views

Is there any comprehensive book or online instruction on image segmentation techniques?

I'm looking for a source to learn theoretical basis of image segmentation techniques thoroughly. The desirable book, or other kinds of source you may know, should cover the techniques that are more ...
4
votes
1answer
101 views

Determining the best month for discriminating between different vegetation types?

I ordered and downloaded several (Surface Reflectance) Landsat 5-8 images from USGS Earth Explorer with the purpose of choosing a few of them to calculate some Vegetation Indices for each (NDVI, SAVI, ...
3
votes
2answers
118 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 ...
5
votes
1answer
132 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 ...
0
votes
0answers
20 views

Is this terminology I'm using is suitable for the field spatial analysis of time series?

I'm going to apply time series concepts to an satellite image, but instead of using time data located on the 'X' axis, I want to use spatial variations on that axis. In addition, the 'Y' axis keeps ...