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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15 views

Can BFAST algorithm be applied to to a whole study area/ ROI?

I am working on identification of breakpoints in Landsat based NDVI time series (1990-2018). I am using The Breaks for Additive Seasonal and Trend (BFAST) algorithm which is a pixel based time series ...
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2answers
104 views

Resampling 1000m resolution Aqua MODIS images to 30m resolution

I am trying to resample the MODIS (aqua) image from 1000m resolution to LandSat image resolution which is of 30m for applying ESTARTFM technique. So you need to do preprocessing (Resampling and ...
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5 views

Get Fmask working, in any environment, with arbitrary satellite images [on hold]

I am working with satellite images from USGS Declassified collections. I want quantify the amount of clouds on them, and I am betting on the Fmask method since Foga et al. think it the best. I realize,...
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18 views

Seeking tool to calculate area specific Tasseled cap coefficients?

It is well established that Tasseled cap coefficients are sensor-specific and are available to disaggregate the amount of soil brightness, vegetation, and moisture content in individual pixels in ...
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11 views

QUAC implementation

Looking for an open-source implementation of the Quick Atmospheric Correction algorithm. I'm trying to create a MATLAB based repository with some essential hyper-spectral imagery tools, one of which ...
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25 views

Exporting large size image from GEE?

When trying to export large size image, I got max pixel range error. Export.image.toDrive({ image: subresult.clip(roi), description: 'Result', scale: 30, crs:'EPSG:4326', maxPixels: ...
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1answer
30 views

Conversion of MLS/AURA RELATIVE HUMIDITY PRODUCT to correctly referenced GeoTIFF

I have downloaded the following product https://cmr.earthdata.nasa.gov/search/concepts/C1251101764-GES_DISC.html and it gives me a .he5file. Can anyone help me in correctly geo-referencing the file ...
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1answer
25 views

Using NDVI along with regular RGB and NIR bands for image classification

Is it plausible to use NDVI along with other regular bands for image classification related data processing? Recently, I came across a comment that RED and NIR band might interfere with NDVI or vice ...
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2answers
40 views

Water reflectance effect on Sentinel 2 images

I'd like to know what is causing the effect on the water depicted on the following screen (sentinel tile id: S2B_MSIL1C_20190805T144739_N0208_R139_T20PPA_20190805T162922 located near Saint Lucia). You ...
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2answers
40 views

How to define new classes from a change detection raster layer [closed]

As part of my thesis, I'm looking at the atmospheric and landscape effects of the 2018 wildfire in the Algarve. As part of the process, I want to estimate total biomass loss so I have classified two ...
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54 views

How can I compute confusion matrix using Python [closed]

My project is about "Extracting water and urban features from satellite images". I have extracted urban and water features using Python code. Now, I want to do accuracy assessment. I know two primary ...
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1answer
32 views

Do I need to perform any corrections on Level-2 Landsat imagery?

My objective is to perform a land cover classification with multiple scenes over historical imagery (one year every decade). Most of the imagery I have downloaded is level-2 imagery. From my ...
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19 views

Registration of a panchromatic satellite image to a multispectral image

I have a multispectral satellite image (RGB and NIR band) which will serve as the reference image. I also have several panchromatic (PAN) satellite images which I need to register to the multispectral ...
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1answer
55 views

How to increase or decrease the spatial resolution of a band in Google Earth Engine?

In LANDSAT var mndwi = ee.Image("LANDSAT/LC08/C01/T1_RT_TOA/LC08_148044_20130425").normalizedDifference(['B3', 'B6']).rename('MNDWI') gives us MNDWI Band In Sentinel 2 the resolutions of Green ...
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1answer
22 views

Fusing Collection 1 Landsat 7 and 8 Surface Reflectance NDVI

I'm fusing L7 & L8 surface reflectance into an NDVI time-series. I'm using the method described in Roy et al. 2016 to convert L7 NDVI to L8 NDVI using a simple regression equation found in table 3:...
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1answer
101 views

Computing MNDWI for Sentinel 2 Images in Google Earth Engine?

MNDWI is the normalized difference of Green Band and SWIR Band. In LANDSAT both are of a similar resolution i.e. 30m. In the case of LANDSAT var landsat8 = ee.Image("LANDSAT/LC08/C01/T1_RT_TOA/...
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31 views

ALOS PALSAR resampling

I want to combine Landsat bands with the backscatter coefficients of ALOS PALSAR. I used the following code to resample and combine. However, the HH, HV bands in combine image showed with 'masked'. I ...
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1answer
67 views

Sentinel-2 range of values, Level 1C (2A)

Is it correct that images (TIFF 8-bit, B2, B3, B4 bands, sentinel-2 L2A, high resolution) downloaded from sentinel-hub have very poor range of values? Min value is about 30 and max value is about 60 ...
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2answers
37 views

Earth Engine casting bands

I am trying to calculate mean reflectance values across landsat 5 and 8 images using the following code: var point = /* color: #d63000 */ee.Geometry.Point([-133.49, 69.18]); var l5 = ee....
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2answers
29 views

Feature space selection for river sand classification using multispectral imagery

I want to perform supervised classification for river sand detection. I have 3 m spatial resolution Surface Reflectance multispectral imagery with B, G, R and NIR bands (Planet data). Which all ...
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33 views

sen2cor BOA output

I have installed all of the necessary programs for this process (Anaconda, Step SNAP, Sen2cor, etc). I have installed the plugin for sen2cor in SNAP. When I run the Level1-c product through Sen2cor, ...
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1answer
51 views

How do I add multiple indices as bands to an image?

I want to be able to classify my image using bands for prediction (B2, B3, B4, etc.) but I also want to use indices as "bands" (B2, B3, B4, NDVI, EBBI, MSAVI2, etc.). Unfortunately, I can't seem to ...
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0answers
46 views

Smoothing MODIS LAI? [closed]

I am trying to smooth 8 days LAI data from MODIS and managed to work around it with several algorithms such as loess, Savitzky–Golay, smooth.spline etc. This is pretty much going well if the level of ...
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101 views

Determining extra seed for SNIC segmentation algorithm

Here is a part of a program that do segmentation based on SNIC algorithm and indeed compute some statistics based on the resulted clusters to determine the worst outlier for each clusters in order to ...
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1answer
23 views

Does per-pixel viewing zenith angle (VZA) is identical between landsat sensors for a common path/row?

Due to the distance from the nadir viewing vector of the satellite, variation in viewing zenith angle (VZA) is observed from the center to the outer edges of the scene (as shown in figure one). ...
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102 views

Aster L1T: Radiance -product to surface reflectance

Earth Engine provides access to Aster level 1 Precision Terrain Corrected Registered At-Sensor Radiance -product (Aster L1T). I would be interested to reach the surface reflectance values of the image ...
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34 views

How do I remove the black background of ASTER in Envi Classic 5.3 “display window”?

I want to change color or remove black bacground of my aster imagery when "save image as" from display window (that loaded as RGB to display.. is there a quick way to do it? here is the what i ask in ...
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57 views

Getting error running GRASS GIS 7.6.1

Here is the error notice I receive after starting GRASS GIS 7.6. I am not sure what is the source of these errors. I had reinstalled the application but it didn't fixed these errors. What are ...
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29 views

Algorithm(s) for Sensor Footprint at limbs

Is anyone aware of algorithm(s) that have been developed for computing remotely sensed image footprints that handle body limbs? The limb is the edge of the body / atmosphere where only the blackness ...
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1answer
31 views

How to modify MODIS subset function to download product for a specific region and time period?

I am trying to assess the land cover change that has occurred over East Asia over last 18 years only in winters (Oct-Jan) for which I want to use MOD13Q1 dataset of modis from 2000-2018. I am using ...
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22 views

Filter Date From FeatureCollection

I want to filter my crop data table on the basis of dates. I uploaded my file in the assets and call it. Now I am unable to filter this data accordingly datewise. The date column is added in the file ...
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1answer
39 views

Moisture Stress Index - how important is seasonal influence in a deciduous forest?

I want to calculate moisture stress index for a deciduous forest using the formula from the article 'Detecting vegetation leaf water content using reflectance in the optical domain' (Ceccato et al. ...
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28 views

Ground Control Point Experience

I have a number of aerial images that do not align with where my GPS says I am. For example, I am standing at the intersection of two roads with a Trimble R10 and a handheld IOS device with the ...
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1answer
88 views

Downloading Sentinel 2 imagery using Semi-Automatic Classification Plugin?

I have been following this video (https://www.youtube.com/watch?v=FcETq8OWM0k) to download Sentinel 2 imagery using the Semi-Automatic Classification Plugin in QGIS 3. However, when I click run and ...
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25 views

Statistic validation for spectral trajectories/trend from ground truth dataset

I'm doing an extraction of spectral trajectories for disturbed forest pixels using multitemporal (single scene for 20 years) Landsat Surface Reflectance products. Usually, forest disturbances are ...
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43 views

Calculating MODIS 8-day composite GPP product as yearly [closed]

I want to use MODIS GPP 8-day composite product for an annual time series analysis. How to calculate the annual GPP from the 8-day composite? Since the fractions represent the daily average rates of ...
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1answer
43 views

Computing the harmonic mean of an image collection in the Google Earth Engine

How can I compute the harmonic instead of arithmetic mean for a series of images in Google Earth Engine? There is a build-in function to compute the arithmetic mean and median, but there is no ...
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1answer
61 views

Extracting atmosphere opacity using Google Earth Engine?

I met some doubts when I try to extract Landsat surface reflection product's atmosphere opacity. the code is : var inCollection7 = ee.ImageCollection("LANDSAT/LE07/C01/T1_SR").filter(ee.Filter....
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2answers
59 views

Hansen Global Forest Change - Forest Loss Year - Dates Clarification

I have scoured both the GFC website, research papers and Stack Exchange, but haven't been able to find a clear and reliable explanation of what the "Year of gross forest cover loss event" pixel values ...
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35 views

Clip a Mask (NDSI) from another Mask (NDWI) in GEE

I have created a mask of Normalized difference Snow Index (NDSI) in the late winter using a combination of Landsat 5,7,8 imagery and I would like to only keep a remaining land features by clipping out ...
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2answers
237 views

Landsat 8 - Reflectance Values

I downloaded some Landsat 8 OLI/TIRS C1 Level-1 images from EarthExplorer. I was hoping to get reflectance data out of the blue, green and red band; however, when I opened those images in ArcMap, the ...
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2answers
1k views

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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1answer
44 views

Make Level-2 Landsat images comparable with Level-2A Sentinel-2 images

Is there a way to make Level-2 Landsat images (e.g. Landsat-5 images ordered from EarthExplorer) comparable with Level-2A Sentinel-2 images? The objective is to calculate water or vegetation indices (...
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1answer
218 views

How big is a MODIS 250m pixel in reality?

How big is a MODIS 250m pixel in reality? This appears to be a question that contains its own answer, but I have several reasons to doubt that the pixel size is actually 250m x 250m: I downloaded ...
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1answer
74 views

Landsat 8 Level 2 products. Converting Pan & Thermal bands to spectral reflectance

We have downloaded around 20 Landsat Level 2 Surface Reflectance scenes for our AoI. The processed bands available in the downloaded scenes are, as you people know - Aerosol,B,G,R,NIR,SWIR,Cirrus. ...
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35 views

What is the 4th band in a 16 Bit 4 Band RGB TIFF? [closed]

I am using TIFF files in a project, all of which are plain RGB imagery. When imported into the software program that I use they are just automatically shown as being three bands, Red Green and Blue. ...
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3answers
106 views

Bare Soil Detection

I try to find bare soil areas. Those which are bare over the whole year and those which are fresh harvest and remain bare over a certain time. I try to do this with sentinel-2 data. But the Problem is ...
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0answers
11 views

Normalizing a single band of landsat 8 imagery w.r.t an adjacent one

We have 23 landsat 8 level 2 imageries which has to be mosaiced. Based on date, we have mosaiced individual bands (B1, B2, B3, B4, B5, B6) and now it's down to 5 imageries. But we are not getting a ...
3
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1answer
121 views

A reproducible example for the use of separability measures in improving selection of spectral variables

I have been working with the tutorials in GEE on supervised and unsupervised classification, but I haven't come across any examples on the use of separability measures such as Jeffreys-Matusita, ...
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2answers
156 views

Removing noise from point cloud with lidR package

I have unclassified Terrestrial Laser Scanning (TLS) point cloud data which has some noise. Is there a function in the lidR package which can be used to remove noise?