Questions tagged [satellite]

In the context of spaceflight, it is an object which has been placed into orbit by humans.

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Unique product name for Sentinel-2 products, which does not change after re-processing by the distributor

Currently, I use the names of the Sentinel-2 space imagery product archives as a unique image identifier in the database. It turns out that this identifier contains processing data and time, which ...
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GPM monthly data is inconsistent with the half hourly data aggregated to monthly

I wrote a code in GEE to first aggregate half-hourly GPM data into cumulative daily precipitation and then aggregate daily data into cumulative monthly data. In the next step, to ensure that my code ...
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Downloading recent GRACE data

I have been doing GRACE data processing in GEE, but from what I can tell - only the first mission's data (dating from 2002/04 to 2017/01) is accessible through the library for import. Can I access ...
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EarthPy plot scatterplot on top of plot_rgb

I am using earthpy.plot_rgb() for some satellite image because it works very well. However, I have the coordinates of a line that I'd like to plot on top of it with scatterplot, but I can't make it ...
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Python Rasterio Writes JP2 without Colors

When opening a JP2 image in rasterio, the image seems to have the width and height dimensions flipped. So, I correct by changing the transform and Affine manually: src = rasterio.open("img.JP2&...
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Getting the real pixel size from scan and track

I'm using FIRMS's Fire data, and in the datasheet, they note two values per reading: Scan and Track. They say that those two values reflect the actual pixel size. How to use them to obtain the "...
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Seeking QGIS Tile / Basemap Options

We have been using QGIS to collect and produce maps for fiber optic deployment to areas where there is no fiber. We use OpenStreetMap as the base tile map, for streets and building structures. We ...
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How can we know that a random satellite image is atmospherically corrected or not using python?

If a satellite image in .tiff format was given. what are the values that can be obtained from a satellite image using python to see whether it has atmospheric errors or not? I am expecting what values ...
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Projection best practices for applying ML to large scale Earth Observation imagery [closed]

I come from a data science background, rather than GIS, but work in a domain where remote-sensed imagery is widely used; so I'm still learning some of the do's & don'ts when it comes to the 'right'...
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MODIS MCD18A2 (PAR) reproject via rasterio vs. via HDF-EOS

I downloaded MODIS L3 PAR data (https://lpdaac.usgs.gov/documents/750/MCD18_User_Guide_V61.pdf, https://e4ftl01.cr.usgs.gov//DP128/MOTA/MCD18A2.061/2014.07.04/MCD18A2.A2014185.h18v04.061.2021258072101....
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What transformation of raw sensor values from Sentinel-2 is GEE using?

What transformation of raw values obtained from Sentinel-2's sensors is Google Earth Engine using? When accessing the data from the Sentinel Hub directly, the values that I get are a bit different ...
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Brush up satellite image coloring

I have received the following satellite image. Unfortunately, the color grading is really poor and makes working with this image very tedious (see screenshot below). I am rather new to QGIS. How can ...
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How feasible is it to scan CORONA satellite imagery in the National Archives?

I'm building a dataset of several hundred historical CORONA satellite images for a research project. I know that one can request these images from the US Geological Survey, but new scans cost $30 ...
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GRASS GIS 7.8.5 i.sentinel.mask Error

I am trying to run i.sentinel.mask in GRASS GIS 7.8.5 I am having the following Error: ERROR: Option <input_file> is mutually exclusive with all of <blue>, <green>, <red>, <...
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Seeking FREE satellite images than ones provided by MapBox [closed]

I have made a desktop map system for myself with NW.js, MapBox GL JS and MapBox.com's free satellite pictures. I don't have money to pay anyone. While it's cool and fun to use, it's largely ruined by ...
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Satellite sun-synchronous orbits and local acquisition time

I have two questions about sun-synchronous satellite orbits. Firstly, I know that equator crossing time for a particular platform is approximately 10:30 – 11:00 local time (descending node). My study ...
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Noisy lines in all scenes for Landsat 7?

I'm seeing patterned lines in all Landsat 7 images that clearly are image artifacts. There are lines that jet in from the edges (the center looks better) Does anyone know what it is and if there are ...
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Image Plane or Object Plane Scanning Satellite Instruments

Scanning systems can be classified as either Image Plane or Object Plane, depending on where the light rays converge, as shown in the following figure. I would like to know if the Terra MODIS, ...
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Are Landsat satellites exactly sun-synchronous?

Sun-synchronous satellites are known to pass over any given point of the planet's surface at the same local mean solar time (link-to-wiki). Landsat is one of these sun-synchronous satellites. I'm ...
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Why are there no Sentinel-2 images in northern latitudes from November to January?

I have found that there are no Sentinel-2 images in northern latitudes from November through January (near 64.11837149, 67.75836280 coordinates). Number of scenes around the point with coordinates 64....
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Latitude, longitude, elevation and altitude of satellites on a specific GPS receiver

I am currently working on calculating the GPS receiver's latitude and longitude coordinates by using three satellites above the earth. I have used the website https://www.n2yo.com/ to get information ...
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Improve ALOS World 3D vertical precision with GPS data from fieldwork

I'm working on sport topo maps in Russia, european part (Pskov region, near Estonia/Latvia border), typical map is from 1 to 10 km2 in size. The most precise source of DEM for generating relief lines ...
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Shouldn't albedo be determined by surface reflectance?

I am new to this field. I'd like to look up albedo in a small area (about 1 sq km), but I don't know much about how to do it. I was hoping to use surface reflectance with landsat correction, but it ...
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What are these rectangular structures on SAR image?

I'm looking through SAR images and I found this (kindly refer to SAR image below). And here's what it looks like on Google Satellite. As you can see, there's no similarly shaped structure found on ...
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Sentinel-2 L2A metadata XML

I am trying to select Sentinel-2 L2A scenes that have low cloud cover. How should I interpret the difference between these three types of cloudy pixel % values captured here? I made this image based ...
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Understanding resolution of multispectral satellite imagery (EuroSAT)

I am trying to understand the data that is provided in EuroSAT : Land Use and Land Cover Classification with Sentinel-2. It is comprised of "Sentinel-2 satellite images covering 13 spectral bands ...
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How to calculate LST in ECOSTRESS data?

I have downloaded ECOSTRESS images, but the LST band values are way too high. How do I convert the pixel values to degrees celsius? Someone said they use the TES method to retrieve LST from the five ...
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I couldn't find Landsat 5 scene starting from 2002-08-04 to 2008-06-01

I am searching for Landsat 5 TM image from 2000 to 2012 in Earth Explorer Web site (https://earthexplorer.usgs.gov/). However, I couldn't find any scene in my study area starting from 2002-08-04 to ...
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How to align set of satellite images?

I have a problem my set of four satellite images (4 different years of observations) of the same area are not aligned and more than that I see that there is a distortion problem also. I found this ...
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Reconstructing satellite sensor swath polygon (multiple orbits, antimeridian crossing)

I'm currently working on a project that involves displaying a given satellite's sensor coverage of Earth, with one of the objective being to count how many swaths overlap a given point on Earth over a ...
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Seeking free satellite imagery basemaps to be used in webapps with frequent updates

I am looking for satellite imagery base maps to be used in my web application. I have been using Google satellite base maps, but they are very old. I need something which has frequent updates, weekly ...
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Why does rasterio compression reduces image size with single band but not with multiple bands

I downloaded Sentinel-2 data. This data have 13 files one for each band as jp2 format. I am reading this images the writing them as GeoTIFF format on python using rasterio. These images are large so I ...
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GDAL: Stitching aerial photos with X, Y, Z coordinates and omega, phi, kappa

Long story short, I have a bunch of aerial images in JPEG that I convert to GeoTiff and a .txt file containing X, Y, Z coordinates and the omega, phi, kappa of each image. I need to stitch all the ...
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Exporting height values in ArcGIS Pro

I have ArcGIS Pro and I need to find a way that would enable me to export a file containing the height values of the entire .NTF/.TIFF files that I'll feed in. I read this manual from ArcGIS to get ...
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Changing MODIS spatial resolution (from 500m to 5km) in Google Earth Engine

I am using MODIS MCD43A4 in Google Earth Engine. I want to change spatial resolution this product to 1km and 5km. Below my code is working well, but I am not sure I could change the resolution easy by ...
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Sat data spatial resolution, where does the XY refer to in the grid?

I have downloaded some NetCDF data. Using R I can obtain the following information for the dimensions > bio_nc$dim$latitude$vals [1] 48.00 48.25 48.50 48.75 49.00 49.25 49.50 49.75 50.00 50.25 50....
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Normalising raster comprised of lots of areas with different MinMax values using QGIS

I've got a raster which is provided to the company I work for on a monthly basis. However, the raster has lots of little areas which have different MinMax values, which give it a pretty bad look, as ...
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Convert ellipsoidal to mean sea level in Trimble Inpho

I have Spot 7 satellite stereo imagery, using Trimble Inpho SATMaster to do model setup. Once I got the stereo view I found the elevations are in ellipsoidal. I tried to convert it using coordinate ...
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Seeking open access 10-30 m spatial resolution imagery?

The data from Landsat-8 and Sentinel-2A&B satellite missions is available at no cost. I am curious to know if there are other sources of freely available multi-spectral moderate resolution ...
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How can I know the specific information of the monthly average data?

I know that the "google earth engine" site provides NOAA's VIIRS-DNB VCMSLCFG information. This is the monthly average data. The satellite photographs the entire earth twice a day, and I ...
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Online PPP Services?

I search different online PPP (PRECISE POINT POSITIONING) services, but I am new in geodesy, so I can find only a few services like: CSRS-PPP (Canada) GPS Analysis and Positioning Software (GAPS) ...
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2 votes
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How to fix white tile issue when exporting Sentinel-2 Satellite images as video to drive

I'm trying to retrieve Sentinel-2 satellite images from Google Earth Engine using Python, and export them as a video to google drive. But the problem I'm facing is that regardless of the export ...
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Is resampling necessary while calculating Normalized Difference Built-up Index (NDBI) on Sentinel 2

The formula for calculating NDBI using Sentinel-2 bands are as follows: Band 11 - Band 8 / Band 11 + Band 8 However, bands 11 and 8 have a spatial resolution of 20 metres and 10 metres respectively. ...
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Landsat 5 missing archives in Africa

I am trying to download Landsat 5 tile on USGS explorer from the Landsat Collection 1 and Landsat Collection 2 dataset in order to do temporal analysis. However, in Africa, I can only retrieve a few ...
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1 vote
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Bare World Satellite Map Base Layer and Tile Server?

I'm fairly new to mapping, and am working on a custom data visualization that will be presented on top of a Leaflet map. We'll be placing our own geoJSON polygons on the map (including labels) and ...
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1 vote
1 answer
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Convert OMI/AURA No2 data from molecules/cm2 to micrograms/m3 (µg/m3)

Currently, I am working on OMI/AURA NO2 data which is in molecules/cm2. I need to convert it to micrograms/m3 (µg/m3) to compare with the O3 concentrations. I have gone through the user guide for OMI ...
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2 votes
1 answer
407 views

Google satellite XYZ tile layer does not display with QGIS 3.16.1

Since I install QGIS ver 3.16.1 the Google satellite XYZ tile does not display. The URL I use is the http://www.google.cn/maps/vt?lyrs=s@189&gl=cn&x={x}&y={y}&z={z} I have no problem ...
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3 votes
2 answers
261 views

Is Satellite Image Continuous Data?

I have a satellite image of one region. I perform interpolation on this image. However, I am not sure Satellite Image is continuous or discrete data.
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2 votes
2 answers
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Calculating GPS uncertainty as a function of general position and time

Is it possible to calculate the uncertainty in a GPS measurement at a given point at a given time by taking into account the number and positioning of the GPS satellites overhead? People throw around ...
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1 vote
1 answer
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What are the white round holes at Antarctica and Arctica visible at pictures from Cryosat-2 satelite program?

At pictures from Cryosat-2 sometimes there is round hole(white circle) at the pole: https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/cryosat-2 https://www.researchgate.net/...
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