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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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3
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1answer
16 views

Evaluating Elevation Change Between Multiple LiDAR datasets

I am hoping to get some insight from others who are familiar with comparing multiple LiDAR surveys to one another. I have two LiDAR surveys with similar extents that I would like compare for elevation ...
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0answers
8 views

Mask clouds across multiple images using Google Earth Engine

I Have multiple Landsat8 images at the same place in different years. I want to have a cloud mask for each image, then merge the mask so that all images will be masked with a same aggregated mask. I'...
2
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1answer
33 views

Applying Google Earth Engine cloud mask on each individual image BEFORE mosaicing the images?

How can I apply a cloud mask to each individual image in a collection THEN mosaic them together based on (for example) mean pixel value across images? The code does not work because the maskClouds ...
0
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1answer
28 views

Is re-gridding a good idea?

I am working with MODIS Aerosol data (the Level-2 AOD_550_Dark_Target_Deep_Blue_Combined product). I am retrieving the data using the LAADS DAAC data API, and requesting all swaths as GeoTIFF files. ...
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0answers
6 views

TIMESAT3.3 output errors

When I ran "fit2img" in TIMESAT3.3,I got problematic result image.Contrasted with original image, this result image seemed to be cut into two parts and was badly deformed.I did not know what happened....
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0answers
10 views

Difference between local and global image co-registration

I want to co-register Landsat and Modis image after Reprojection and Resampling. So for that I was trying to understand the difference between local and global image co-registration of this library. ...
1
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1answer
41 views

Which band to use for LSWI?

I have a sentinel 2 L1C data and I am trying to calculate the Land Surface Water Index (LSWI) using the NIR and SWIR bands. As the Sentinel 2 data is having 2 SWIR bands (B11 and B12), I am confused ...
2
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2answers
49 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 ...
1
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2answers
114 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 ...
1
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1answer
31 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 ...
1
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1answer
30 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
44 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 ...
1
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0answers
56 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 ...
2
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1answer
35 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 ...
0
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0answers
22 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 ...
2
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1answer
64 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 ...
2
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1answer
29 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:...
0
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1answer
116 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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0answers
47 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 ...
1
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1answer
76 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
38 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....
1
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2answers
30 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 ...
0
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0answers
44 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, ...
2
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1answer
54 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 ...
2
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0answers
49 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 ...
0
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0answers
110 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 ...
0
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1answer
29 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). ...
0
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0answers
134 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 ...
0
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0answers
40 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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0answers
59 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 ...
0
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0answers
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 ...
0
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1answer
37 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 ...
0
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0answers
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 ...
0
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1answer
45 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. ...
0
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0answers
30 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 ...
1
vote
1answer
123 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 ...
0
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0answers
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 ...
1
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0answers
50 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 ...
2
votes
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 ...
0
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1answer
70 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....
0
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2answers
68 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 ...
1
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0answers
39 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 ...
2
votes
2answers
275 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 ...
4
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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 ...
2
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1answer
136 views

Convert Planet Imagery Surface Reflectance product DN to surface reflectance values

I have a PlanetScope Ortho Scene Product (3B) which includes an AnalyticMS.tif and AnalyticMS_SR.tif files. Based on what I have read so far, the AnalyticMS_SR.tif file is scaled surface reflectance ...
1
vote
1answer
45 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 (...
2
votes
1answer
243 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 ...
1
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1answer
81 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. ...
1
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0answers
36 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. ...