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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7 views

Bulk Download App 'Insuficient Previledges'

Ordered Landsat 7 data from USGS and wants to download it using the Bulk Download application. However, i get this error while running the software. I have JRE Installed properly. Does someone knows ...
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1answer
20 views

How to represent seasonal variability in a single global NDVI map?

I have twelve monthly MODIS datasets for a 1 year period (http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MOD13A2_M_NDVI&year=2015) and wish to combine all the data into a single map highlighting ...
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0answers
13 views

What units are associated with these raster bands?

The picture is a scatterplot of roughly 400 pixel values from 4 different raster bands. Im curious what the units are? They do not correspond with the sensor's band values. Sensor is WV-II. 1 - Red ...
2
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1answer
60 views

KEA File Conversion using gdal_translate

I was using ARCSI (The Atmospheric and Radiometric Correction of Satellite Imagery) to convert a 'kea' file format to 'tif' format using this gdal statement (gdal_translate –of GTIFF LS8_sref.kea ...
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0answers
15 views

Why Pixel value is zero in Image metada? Do Pixel value and file pixel value represent different or same meaning?

I have opened a Raster Raw image in Erdas Imagine and stacked four bands and I opened the stacked image in software. After I opened the metadata from home menu. I clicked on Pixel and saw that all ...
3
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1answer
55 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 ...
2
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2answers
515 views

Classification, Change detection and NDVI Using (landsat2 MSS), (landsat5 TM), (Landsat7 ETM+) and (Landsat8 OLI)

I have 5 Landsat images for the same study area. One of them in 1975 (Landsat 2 MSS), two in 1985 and 1995 (Landsat 5 TM) and one in 2005 (Landsat 7 ETM+) and the last one in 2014 (Landsat8 OLI). I ...
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3answers
41 views

substitute for landsat 7 for land classification?

I am doing a project where I need to do a land classification for a forest reserve in Honduras. The dates I need are 2005, 2010, and 2015. I'm good for 2015 with LS8, but I am having difficulty with ...
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1answer
185 views

NDVI values for MODIS images [duplicate]

I have downloaded NDVI MODIS 500m image i.e. MOD13A1. From the hdf format that i got i converted them into tif format using the HEG tool. The images that i got some are showing pixel values -32767 to ...
2
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1answer
260 views

applying savitzky golay filter to modis ndvi data

I want to smooth the ndvi MODIS 16 bit integer data .tif for LULC classification . i have timesat 3.1 software on windows but i don't how to apply the SG filter . i am not that good in programming . i ...
3
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1answer
46 views

Random Forest out of the bag and confusion matrix

I have implemented Random Forest classifier to classify remote sensing data in R. The original code comes from here: How to perform Random Forest land classification? Everything works fine, but what ...
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1answer
34 views

How to calculate GSD(ground sample distance) from zoom level and vise versa

I am an application programmer, a beginner in the GIS domain. I have an image with its ground sample distance parameter. I need to associate the zoom level with GSD. I am using MapBox.
2
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1answer
31 views

vegetation classification from only the panchromatic band

I am mapping mangroves over a period of several years using satellite imagery. I use QGIS semi automatic classification plug in. Supervised classification (maximum likelihood) as I can visually ...
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0answers
14 views

Complex Coherence with SNAP or SarScape

is it possible to estimate the complex coherence between two RADARSAT-2 SLC images with SNAP or SarScape? If I try to estimate the Coherence I get only float data but I need it in a complex form.
3
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1answer
451 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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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 Landsat-...
4
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3answers
111 views

Where / How to download Sentinel 2 Images

I need Sentinel 2 imagery of Nigeria, I signed up in Copernicus Scihub but typing Nigeria into the text box no results appear. I must be doing something wrong, how can be possible that they do not ...
3
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2answers
117 views

Removing cloud from Sentinel 2A imagery?

I would like to use sentinel 2A imagery to look at canopy cover in Northern Vietnam. The only problem is that ALL the recent images have large amounts of cloud in the area I want to look at. Is it ...
4
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2answers
51 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/...
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1answer
44 views

After doing TOA correction to a lansat 8 image band using raster calculator, the reflectance is slightly out of range. Why is that so?

the reflectance range was like for example 0.0023 to -1.02356 for some band and -0.0156 to 0.009. Why is this reflectance range slightly out of range? Isn't it should be in exactly in between 0 to 1. ...
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1answer
30 views

modis surface reflectance

I wanted to perform atmospheric correction using MODIS surface reflectance products for validating my atmospherically corrected images (from Landsat 8). As Landsat 8 only became available in 2013, is ...
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0answers
16 views

Why can't get correct RGB img of Landsat 8 using np.dstack

I use np.dstack to stack Band4, Band3, and Band2 of Landsat8 data to get ture color image,I use code from Milos Miljkovic, but the result looks incorrect. import numpy as np from matplotlib import ...
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0answers
22 views

Downloading high resolution multi spectral commercial satellite images

how can i download high resolution multi spectral commercial satellite images like rapid eye, worldview etc. that have less return period like 1,2 or few days .And i need image of Pokhara city of ...
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0answers
37 views

land sat 8 sensor zenith and azimuth angle

i need Landsat 8 sensor zenith and azimuth angle for atmospheric correction using 6S but in "mtl" file only solar zenith and azimuth angle information is given
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0answers
48 views

Setting background value transparent in ENVI 5

How might I set the nodata/background value as transparent in ENVI 5.0? I know that I can edit the header of the file and set the "ignore value" field, which I tried (setting the field to -3....
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0answers
12 views

sensor zenith and azimuth angle

if SUN_AZIMUTH = 153 then sensor_azimuth would be=153 and if sun zenith is = 57, then sensor zenith also equal to =57? is there any relationship between them?
26
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7answers
4k views

Machine Learning Algorithms for Land Cover 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 ...
3
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0answers
15 views

Snapping vectors to vertices for ROI delineation?

I am trying to manually extract a set of ROIs in ENVI 5.0. However, I can't seem to successfully line up the vector to be flush with the boundary of the pixels, which means I don't have fine-tune ...
1
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2answers
571 views

view zenith angle and view azimuth angle with Quickbird

I am trying to do an atmospheric correction on a Quickbird scene. I am creating a user-defined geometry which requires six parameters. The six parameters are solar zenith angle, solar azimuth angle, ...
1
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1answer
228 views

Maintaining spatial integrity of Matlab matrix with missing data

I am working with MODIS Terra imagery (MOD13Q1). I am currently trying to compute the autocorrelation structure of the pixels in an MODIS NDVI raster. The problem is that I have clipped the original ...
2
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0answers
336 views

Format of raw LiDAR data (time-of-flight data)

I am doing a project where I need to simulate LIDAR data, and I am looking for specifications on how raw LIDAR data looks. I want the format of the data before it is translated to x,y,z coordinates (...
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0answers
24 views

Calculating Excess Green / Excess Red vegetation indices using Adobe CS6

I am undertaking an agricultural mapping project in which I'm imaging a field using a UAV equipped with a 16.1MP RGB digital camera. I am attempting to process the images to yield vegetation indices ...
2
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1answer
45 views

Georeferencing an oblique angle photograph in repeat-photograph studies

Backround: Aerial photography and remote sensing can be used to measure current land cover and recent land use change. However, these technologies are fairly recent and therefore time series are ...
1
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0answers
31 views

Combining hyperspectral bands to form a multispectral image?

I understand that the difference between the two are the number and width of the bands. Given a hyperspectral image, is it possible to 'convert' it to multispectral ? In this paper for example, the ...
3
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1answer
23 views

Except from Hyperion do you know any other hyper-spectral satellites?

There aren't many images for my research area. So I am looking for other hyperspectral satellites. Or maybe another site except USGS? The area is near here "40.223124, 23.031155"
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2answers
44 views

Landsat 8 Band Value Range

I'm confused as to the range of brightness values associated with Landsat 8 Bands. I know that for Landsat 7 and below it has always been 0 - 255 but some of the literature indicates that Landsat 8 ...
1
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1answer
40 views

Hyperspectral Imaging - Material spectral signature

I am reading about the working principles and applications of hyperspectral imaging (HSI). In this link, the uses of HSI over the range of the wavelength, from visible to longwave infrared have been ...
2
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1answer
467 views

Python script for dark object subtraction on Landsat 8 Imagery

Does anyone know of any python scripts that will allow me to conduct such a process? I am limited to open source software and have minor experience in Python.
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0answers
59 views

How to analyze Vegetation Index using Sentinel-1 SAR Imagery?

I am using the ESA open scientific data hub for Sentinel 1 SAR imagery (Interferometric Wide swath SLC VV polarization) and would like to know how to perform vegetation health analysis from this data? ...
11
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1answer
647 views

Multispectral image segmentation for natural-resources applications using R

R has the capacity for image segmentation, although all of the examples I have come across utilize a single band for the segmentation (example). I am interested in combining R's capacity for random ...
2
votes
1answer
39 views

MODIS temperature and NDVI data?

hope anyone could give me some hints here. I tried to download free MODIS data from their page(resolution 500m, 1km). Im interested in NDVI and temperature data. But when i load the hdf files into my ...
2
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0answers
22 views

Converting CDF file to NetCDF file to use in ArcMap? [duplicate]

This is a GIS question as well as a Remote Sensing question. I have downloaded CDF files from the ESA from MyEarth online and want to use them in ArcMap. In ArcMap you can Make NetCDF a Raster Layer. ...
0
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2answers
120 views

Satellites to retrieve UV bands

I want to retrieve some satellite images with UV bands,Bun I don't know which satellites are providing UV bands and We can freely download them? I have already downloaded Modis and Landsat images,But ...
19
votes
3answers
5k 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 ...
2
votes
2answers
915 views

How to perform an accuracy assessment in eCognition?

How to do accuracy assessment of classified images in ecognition? I have done the image segmentation for Worldview-2 image. Then, I have processed for classification for class names (e.g road,...
2
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0answers
62 views

Calibration error for Sentinel 1 image in SNAP toolbox

I am working with a Sentinel 1 SLC IW image (VV+VH) and trying to calibrate the data in the SNAP toolbox. However, it keeps returning the error "cannot construct data buffer" Does anyone have any ...
1
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1answer
49 views

Getting latitude-longitudes from tiff and world file

I have downloaded Version 4 DMSP-OLS from here, which is a bunch of tiff files with their world files. I would now like to crop an area specified by bottom left and top right lat-long points. I ...
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0answers
14 views

MODIS MCD43A3 albedo product: good quality observation and fill value at the same time?

I’m using the MODIS MCD43A3 albedo product on one of my projects. I only used the good-quality values determined based on the BRDF_Albedo_Quality band recorded in the associated MCD43A2 product. ...
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0answers
23 views

Spatial Resolution (Scanning Precision)

I am using Landsat_7 image and details is pasted below: - Date of acquisition: January 2001 -Pixel size: 25 m -Spectral bands:  Band 1: Blue 0.45-0.52 µm  Band 2: Green 0.52-0.61 µm  Band 3: Red 0....
1
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1answer
27 views

Remove raster pixel in R

This is the 32 year trend NDVI (raster data) I would like to remove the green grids data by using R (the green pixel value is larger than 0.03) and this one is R code that i use but i cannot ...