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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QGIS - clip a large amount of rasters - starting from a WMS layer

I would like to make a comparison of mangrove health and cover, between 2008 and 2022, at the scale of a region. For this, I will use a satellite imagery, taken from the plugin : "...
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Crop Water Stress [closed]

I am trying to calculate crop water stress using Sentinel-2 imagery, What's the equation that's used to calculate crop water stress index?
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Negative Rrs on SeaWiFS file

I'm working with the following file "SEASTAR_SEAWIFS_GAC.20030716T122701.L2.OC.nc" Which can be accessed through here: OceanColor-Nasa-URL After accessing the Rrs I noticed that there seems ...
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Meaning of "advance(-2, 'month')" in GEE

I am learning GIS using Google Earth Engine. When learning "Changing detection" I have this code: // Define the area of interest var geometry = ee.Geometry.Polygon([[ [76.37639666685044, 11....
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Combining Reducers in Google Earth Engine to Calculate Mean Annual Temperature

I'm new to Google Earth Engine and am hoping to calculate and visualise mean annual temperature for Ethiopia using the TerraClimate: Monthly Climatic Satellite dataset, ee.ImageCollection("...
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Can I use histogram matching to harmonize two sensors data? (SPOT and Planet)

I have to image collections of SPOT (airbus) and Planet. The images are not overlapped (from different locations) and are not from the same dates. However they have RGB-NIR. I would like to be able to ...
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How to know the spectral range (or spectral domain) of an composition bands?

In the image segmentation process, the spectral range (or spectral domain) is an important parameter in the construction of segments in an image. considering an 8-bit image,with a size of 3*3 pixels, ...
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In remote sensing and image processing what does the term "spectral domain" mean?

In remote sensing and image processing what does the term "spectral domain" mean? How could this be understood in an image segmentation context? In an article on segmentation of satellite ...
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Determining sea surface salinity with multisprectral satellite imagery

Could anyone with knowledge of remote sensing tell me if multispectral satellite imagery such as Landsat 8 or Sentinel 2 can be used to determine salinity differences in ocean surface water? My ...
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RPC sensor model coefficient auxiliary data structure

I am part of a college team building a hyperspectral small satellite (3U). We would like to use ENVI's orthorectification module to do ortho. However, we need to generate our own RPC or sensor model. ...
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What is name/terminology for area in .tif satellite image file which is blank space/not land?

I have some L2 satellite images from an MSI bundle, and I need to produce a mask over the area in the file which is not the image itself - the black part in the image below. What is the technical name ...
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Adding validation point over image in Remote Sensing software

I want add validation point of bamboo sites using coordinate value on sentinel image using any Remote sensing software like ecognition or ERDAS imagine? Is that possible or should I need to use GIS ...
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Problem Facing while performing Interferometry using Sentinel-1 image

I am using sentinel 1 data to extract the surface elevation using snaphu-unwrap tool. I perform all the steps according to literature and all the steps provide data too. However in the last step where ...
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MEAN satellite zenith angle for WorldView imagery

Is satellite zenith angle (view zenith angle) for a WorldView imagery = 90 - satellite/view zenith angle (just as we do for solar zenith image)?
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Differentiating Bamboo with validation Points

I need to work on bamboo distribution mapping using sentinel-2 data for my project. I found many researchers mentioning Bamboo Index calculated as (BI) = (NDVI-SI)/(NDVI+SI) Where; SI is Water Stress ...
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In which software do I add a watermark to the map?

I want to know in which software I can do the following operations (esri/ pci/ hexagon et.)? Adding Watermark to the satellite image/coordinated map. Make the added watermark invisible Detect which ...
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I am using BFAST to do a time series analysis of LST and I am getting NaN errors

This is the blog post I refer to, https://philippgaertner.github.io/2018/04/bfast-preparation/, and the author's code is as follows: # NDVI data data(tura) selected_pixel <- 90 represents a ...
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Missing tiles in Sentinel 1 data

I am working with VV/VH Sentinel 1 descending data in Google Earth Engine but there are large areas misisng as shown in the screenshot below. The image indicates the mean data from 1-31 August. The ...
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Trying to obtain image with max NDVI value for each month of the year across multiple years using Sentinel

For my project, I am trying to obtain a single image for each month that represents the maximum NDVI value for that month across several years. So, basically I want 12 data points across the range of ...
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Can we do soil analysis for Nitrogen using remote sensing without field data for validation? [closed]

Background: Remote sensing is used for monitoring land cover change and for monitoring vegetation etc. In addition to that, it is used for soil analysis (alterations in soil properties) as well. There ...
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Classify Land Use Land Cover

I am asked to classify an image (Landsat 7 scene) for 2 different time period one for the month of July (Image 1) and the other December (Image 2) as shown below. Image for the month of July Image ...
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Change ruleset for images using E-cognition Software

I need to work on Object Based Image Classification using E-cognition software. The first map is as shown below: - This map belongs to that from the month of June. The other map is as shown below: - ...
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Detection of permanent changes in low resolution images

I want to detect permanent changes in lows resolution sentinel-2 satellite images, such as new buildings. Most research I found focuses on pair-wise change detection, which leads to many false alarms ...
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Sentinel-1 No products found - Looking for alternatives

I'm interested in doing flood mapping for a specific region, using SAR images from before and after the event. However, Sentinel-1 images are missing for this region (no products for more than 8+ ...
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1 answer
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How to calculate and export a table of mean of the maximum daily NDVIs over a particular period

I am using code from Nina Kattler to calculate the mean of max daily NDVI in particular districts in Mali over the growing season in 2019. The original code gives the mean NDVI over the growing season,...
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LandSat Land Surface Temperature - Python

I'm trying to determine if my code for determining land surface temperature is correct. The imagery contains a fire in the middle of October with snow mixed in so temperatures show be nice and ...
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Seasonal/monthly image composite generation for crop classification

I want to create multi-temporal composites for crop classification. However, when I print, I get 36 bands, but I was supposed to get 27, right? Besides, if I want to add multiple indices to each of ...
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Eliminate mismatch between two GeoTIFF satellite images

I have two GeoTIFF satellite images of the same area made on different dates (both are in the same CRS). When I open the images in QGIS, I can see that objects (buildings, etc.) have slightly ...
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Should I re-scale all the dataset to one scale before running them into model?

I have been working on the Flood susceptibility modelling and also have identified, collected and generated data of around 26 controlling factors(indicators). Furthermore, i'm going to put them into ...
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Eliminate mismatch between building images and their shape file annotations

I have little experience with geospatial data processing. I have a satellite image of an area (a geotiff file) and building footprints (building annotations) for this area (a shape file). When I open ...
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Mapping Soil Sealing and Water Bodies

I am asked which bands of Landsat 9 (or 8) is best for mapping soil surface sealing and water bodies at higher resolution. The band available in Landsat 9 is as shown:- From above band name; which ...
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Difference in color saturation in two Landsat-8 images

I have an assignment, where I have to do a classification and change detection between to satellite images. Now I have two Landsat-8 images from two different years (2019 and 2020) at captured nearly ...
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Image.classify: Classifier has no training data

function clip(image){ var image_clip = image.clip(corn); return image_clip } //corn,代码编号为0 function setcorn(feature){ var new_feature = feature.set({landcover:"corn",index:0}); ...
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Quick Map Services (QMS) Google Satellite Imagery Source Date

I have digitized landform features using the QMS Google Satellite as a reference basemap, and therefore need to know the date the image was taken. Is the plugin a 'live' updating feed from Google ...
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Change system:index of FeatureCollection ID in GEE to use Asset ID

I have a FeatureCollection with points loaded from an asset (shapefile). Since the system:index is empty, gee assigns a weird index to each feature (e.g. 000000000001, 0000000000a).Which causes ...
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Point value Change after projection - USGS DEM Raster VS Imagery Layer from Esri

I'm working on a project that requires National level DEM data, and Esri are providing the imagery layer (https://www.arcgis.com/home/item.html?id=0383ba18906149e3bd2a0975a0afdb8e). For the most part,...
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Calculate yearly change of LST data from MODIS in QGIS

I have monthly raster scenes (June) from MODIS for the period 2000-2020. So for each year one scene. Now I need to determine the yearly change in temperature for the month of June per pixel in degrees ...
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Why does no one use MODIS data from 2000?

While MODIS Terra was launched in 1999 and has data covering the year 2000, no one seems to use this in their analysis but rather starts the data collection from MODIS by the year 2001. Why is that? ...
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Bare soil detection using drone images

I'm working with drone images which separated to red, green and blue bands. My task is to determine bare soil pixels. I've tried to swap bands in the composite, and calculate different differences ...
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Error in generating a chart: No images in the collection intersect the specified regions

I am getting an error saying: no images in the collection intersect the specified regions thus my time-series chart cannot be generated. What might be the reason for this? The link to my code https:/...
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Atmospheric correction on Landsat scene using Python

I need to develop a workflow to analyze Landsat and Sentinel 2 scenes using Python and Xarray library. Generally I do this task using QGIS and Semi Automatic Classification Plugin, I'm using the ...
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1 answer
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Is there any way that can help determine the flow direction of a river in a satellite image (Landsat)?

For example, there is a stream in the following image, but I find it difficult to determine the flow direction of the stream. Should it be from south to north, or the opposite?
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No training data found (random forest algorithm in GEE)

I was trying to map rice in the Indramayu Regency in Indonesia using the random forest algorithm. It has responded with no training data found. When I used the same code previously for a different ...
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Band used for deformation estimation using In-SAR

Which polarization of SAR data (C-band - Sentinel-1A) shall I use to get a better deformation map of a mountain terrain - VV or HH?
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Vegetation Identification Plugin for QGIS

I was wondering if anyone knows of a deep learning plug in for QGIS that can identify different species of vegetation using high resolution RGB or multi-spectral imagery. Unfortunately I have not been ...
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Does a remote sensing image pixel value represent mean or max reflectance in a given band's wavelength?

This is especially relevant to multispectral sensors with wide bandwidths. For example, Sentinel-2's band 2 (blue band) has a bandwidth of 66nm, spanning ~459nm-525nm. If a pixel has a value of 1500 ...
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Is there a way to filter out polygons/lines using geometry in QGIS?

I am currently working on a project to digitize utility data, however my input layer is not classified. I am currently using length of the features to filter out unnecessary lines/polygons. Is there a ...
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Calculate transition of different NDVI classes from pre and post NDVI in Google Earth Engine

My competency in GEE is quite low. I have calculated 2 NDVI layers (pre and post-disturbance NDVI). I have separated these NDVI layers into 4 classes according to NDVI values. Now I need to calculate ...
6 votes
2 answers
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Applying HDR (high dynamic range) rendering in QGIS

I want to automatically (without manual adjustments) apply HDR (high dynamic range) rendering to Sentinel-2 satellite images so that the image can distinguish between very bright objects (e.g. clouds, ...
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Adding external data to NDVI Chart google earth engine To have Two line charts on the same plot

I am trying to add external data to ndvi chart on google earth engine in order to have both lines on the same chart. I have been able to plot them differently but not able to merge them. Here is my ...

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