Questions tagged [remote-sensing]
Questions about measurements which are taken from remote locations / are not taken in situ.
114 questions
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footprints L2 IASI data
I tried to process the L2 NH3 data from IASI.
How can I estimate the elliptical footprint of a pixel from the following geolocation and geometry data for the IASI instrument?
The available information ...
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How can I convert methane concentrations from kg/m2 to ppm?
I am working with the IASI MetOp-B satellite data which provides information on intergrated methane in units of kg/m2, and I would like to convert it to ppm , i have also the information of surface ...
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Indirect evidence for the Americas [closed]
The existence of the Americas to the peoples of the old world is, nowadays, indisputable. However, this was not the case 600 years ago (for most of Europe).
Columbus landed in the Bahamas, leading to ...
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Reading MSG Native(.nat) file with satpy
I am trying to read an MSG (Meteosat Second Generation) file given in the native(.nat) format using satpy. I tried using:
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What does the SST field represent in the GFS forecast/ analysis?
What does the SST field represent in the GFS forecast/ analysis? For example, in the ERA5 reanalysis product, the SST is a foundation SST taken from the OSTIA. Similarly, what is the SST in GFS? Is it ...
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Are DInSAR and InSAR same?
I am reading papers that talk about InSAR methods. For subsidence, some papers have employed DInSAR approach and others InSAR. While the methods section explanation are similar, I would like an expert ...
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What's the strongest earthquake we currently can miss observing on Earth?
Reading jeffronicus' answer about how seismic stations record bomb explosions, particularly the reminder that the intensity of earthquakes drops by distance, made me start wondering what scale of ...
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Are seismometers over the world "feeling" the small earthquakes caused by air raids and shelling on Gaza Strip?
When watching news about earthquakes, I think most people are used to hear about the Richter scale, a logarithmic scale used to measure earthquake intensity. A very strong earthquake, like the 2011 ...
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Tech stack for crop related information using satellte data
I want to perform tasks like crop area estimation, crop yield estimation, crop growth stage monitoring using Sentinel 2 or Landsat data for a particular region. What tech stack would I need to do that?...
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Single-Antenna-Single-Pass SAR interferometry
As I understand, for elevation mapping using InSAR, one typically requires an out-of-plane baseline to create the required phase difference between images to detect objects at height. This usually ...
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How we convert TOM
TEMIS NO2 tropospheric Data by KMNI Netherland is retrieved in TOMIS (ASCII) format. My issue is to convert the said format in to ESRI Gird format or any other Raster format to analyze the retrieved ...
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Question about VV and HH polarizations in radar
I am doing something with ASCAT which is measuring backscatter to reflect the status of soil moisture. Some research indicated that VV polarization is much more suitable for soil moisture measurement ...
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Remote sensing and GIS
Please how can I get landcover landuse data from landsat 4 or landsat 5.
Please can anyone help me and provide me the details?
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Why is the ρστ absorption band called the ρστ absorption band?
Differential absorption in the near-infrared is used to retrieve total column water vapour from MODIS (Gao and Kaufman, 2003), OLCI (Preusker et al., 2021), and others. The idea is that reflected ...
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How to use actual evapotranspiration in irrigation scheduling?
I have estimated actual evapotranspiration using the Penman-Monteith method and by using remote sensing data.
I have weekly evapotranspiration images. How to utilize this in irrigation scheduling? How ...
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What is this error regarding easting and northing of ground control points?
*I want to understand what would it mean by easting of ground control points (GCP), and what would it mean to have rmse of x m with a minimum of a m.
The average root mean square errors (RMSE) in the ...
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Difference between Hillshading and Terrain Resource Information Management
I am picking up on remote sensing. I came across a paper where they use the shaded relief model from Terrain Resource Information Management (TRIM) for hillshading. However, is it the same as the ...
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Forest canopy structure
Optical remote sensing technology is commonly used for forest biomass estimation. The NDVI is used to define greenness. But how can we tell about biomass after capture only canopy area from above? Is ...
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How is tree age estimated?
I am trying to study about forest biomass and carbon amount of forest.
First of all, I studied some papers, they mentioned that age of forest is related to the biomass. So, How do we measure the age ...
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Do farmers gain any particular benefits from crop monitoring?
Recently, crop monitoring through satellite or other remote sensing devices has become a hot topic. However, I was wondering if, say, satellite data combined with ML software mapping out crops being ...
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Visible satellite imagery, atmospheric anomaly (descending air) in cumulus fields?
When looking at GOES satellite imagery, in the visible channels. I have noticed these "lines" if you will, usually forms in Cumulus fields. I understand the process of the 'Mackerel sky' (...
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What is the elevation angle of sun at lunar poles?
The Moon's orbital plane is inclined by about 5.1° with respect to the ecliptic plane, whereas the Moon's equatorial plane is tilted by only 1.5°.
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DEM coordinates do not align other data layers
I recently downloaded Original Product Resolution (OPR) Digital Elevation Model (DEM) data for some analysis. The DEM do not align with any of the other data sets I have for the area. How can I ...
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The-nature-of-sar-pixel-value-vs-of-panchromatic-pixel-value
When we compare sentinel-1 SAR orthorectified 8-bit image vs a very high resolution panchromatic 8-bit image, the panchromatic cells are a resemblance of signal amplitude in an 8-bit scale (0-255). ...
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Pansharpening of Landsat 8
If I have a four band Landsat 8 image (Blue, Green, Red and NIR) and pansharpen this image using the panchromatic band. How accurate would the pansharpening be for the Blue and NIR bands? See band ...
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Remote sensing of glaciers, season for data collection
I would like to understand to view the health of a glacier using optical or SAR data. What season would be the best for observation? Is the ablation season better or the accumulation season? More ...
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How can I relate aerosol particle size (2, 5 and 10 microns) with the aerosol index measurement of the Sentinel-5P (TROPOMI) data sets?
I would like to know the relation of aerosol particle size (2,5 and 10 microns) with the measurements from the Sentinel-5P TROPOMI data, in the wavelengths 340-380 and 358-388 nm bands.
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What are those precipitation and water droplet characterization instruments called that they put on meteorological aircraft? How do they work?
A long time ago I did some reading on Mie scattering and atmospheric particulate counting and I got sidetracked on raindrop characterization.
I remember reading about light and laser based ...
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Normalized Difference Vegetation Index sensitivity to soil
A lot of papers mention that Normalized Difference Vegetation Index (NDVI) is sensitive to soil background such as bare soil. My question is what is the exact reason behind the impact of soil on NDVI?
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Why does SNAP let me open some Sentinel-5p products and not others?
Good morning,
I am working with Sentinel-5p products, my final thesis is to establish a methodology for processing this type of images, from downloading to the implementation of a colour map with the ...
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How do I convert Sentinel-5p / TROPOMI vertical column density to concentration?
I am doing an study on Sentinel-5p TROPOMI images. I would like to convert the data from mole/m2 to μg/m3, for this I know I need the height data of the measurements. I have looked for them and I have ...
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Can I regard the grayscale of a RGB color image as a panchromatic image?
Here I have a remote sensing dataset with many bands (e.g., blue, green, red, ...), and I use the blue, green and red bands to get a true color image. I want to know if I can get a panchromatic band ...
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Is there any intuitive and easily understandable way to help students understand the triangular facet of outcropted stratigraphy?
I find it difficult to teach college students about using the triangular facet on remote sensing images to judge the dip direction of sedimentary formations. Is there any intuitive way that can help?
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How can we distinguish fold and cycle of sedimentation on a remote sensing image or in the field?
A fold is composed of stratigraphy that is symmetric and repeated. Cyclic sediments (also called rhythmic sediments) are sequences of sedimentary rocks that are characterised by repetitive patterns of ...
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Free periodical satellite/aerial imagery
There is a company called Planet Labs which sells daily satellite imagery covering the whole globe that can be used for various research like agriculture, forestry etc. I wonder if there is a free ...
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Is there a name for a type of algorithm or processing which uses only one source of data as input?
Many algorithms in remote sensing take one or more different datasets as inputs and return some output. An example might be computing the amount of sulfur dioxide (SO2) injected into the stratosphere ...
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Where can I find canopy reflectance data for crops (soybean in particular) for different dates across the growing season
I have been trying to find literature values for reflectance of soybean for different dates along the growing season (I am specifically interested in 30, 60 and ~120 days after planting - so the V3/V4 ...
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Lead remote sensing?
I am trying to formulate a research topic centered around the environmental effects of general aviation's continued use of leaded gasoline (containing tetraethyllead) to power piston aircraft. In ...
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How to convert mol/m^2 to total mass ( e.g gram, kg etc )?
I want to calculate the total $\rm{NO_2}$ amount in a year using satellite Sentinel-5p NO2 dataset. But the problem is sentinel satellite data stored in $\rm\frac{mol}{m^2}$ unit. But I have to ...
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Landsat 8 acquisition time and date
The the meta data text file that comes with Landsat scenes, contains an acquisition date and a scene center time in successive lines. I wanted to know if the image is recorded at the scene center time ...
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What is the use of HV or VH polarization in Radar?
Radar is a common tool in remote sensing, it is a so-called active instrument, hence it emits and receives energy. Modern Syntethic Aperture Radar (SAR) systems are capable of both transmitting and ...
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NDWI from Landsat 8
I have layer stacked Landsat 8 image, how can I calculate Normalized difference water index (NDWI) from it?
I would have been able to calculate it easily using the raster calculator, if I had the ...
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Planetary Reflectance vs Relative Spectral Response
I am confused between a Planetary Reflectance and the Relative Spectral Response (RSR). What I know/guess is that RSR is a response/function of an Instrument band's reflectance against a spectral ...
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How do the pros measure humidity?
I have used a wet/dry bulb setup to estimate humidity, and it appears that the Argentinian meteorological service uses one in Antarctica as well.
Wikipedia sez:
Humidity measurement is among the ...
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District/province wise air quality data for South Asia (2010 onward)
I would like to create a district/province-level air quality data for all the countries in South Asia from 2010 onward using satellite data.
As someone with absolutely zero background in remote-...
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What are the differences between down-looking and side looking radar?
In Radar concept the SAR-Synthetic Aperture radar performs as side-looking to collect information, why it is not downlooking? There are down-looking radar also. So what are the differences between ...
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Pansharpening of Spot 6 image
Would the pansharpening of Spot 6 work on the NIR band? Since the wavelengths captured by the panchromatic band does not overlap with the NIR band. The band designations are in the attached image.
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Google earth historical imagery date
I am working on a small creek in Colorado using historical imagery via Google earth. I want to know if the imagery date at the bottom of each image on google earth is the date the google acquired the ...
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What is the meaning of nomalized difference Built-up index？
I know how to calculate it by remote sensing image, but why do we define this?
What can we know about a remote sensing scene by this indicator?
What's the connection between normalized difference ...
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Regional and Relative Sea level
I am a little confused by the terms "regional" and "relative" in the sea level change context.
Do the two words have the same meaning? Does the "regional MSL trend" in https://www.aviso.altimetry.fr/...
