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13 votes
Accepted

Removing cloud cover using Sentinel Toolbox?

ESA's Sen2cor Toolbox removes haze, cirrus and cloud shadows, not dense clouds. It's performed over the same scene, not by mosaicking. The AC flow is the following from L2A algorithms document: So, ...
aldo_tapia's user avatar
  • 13.7k
10 votes
Accepted

6S atmospheric correction results wrong

Short answer: It's a numerical precision issue: the xa, xb and xc coefficients are not displayed in the 6S output file with enough precision to produce the correct answer when using the formula. It is ...
robintw's user avatar
  • 4,006
9 votes

Atmospheric correction algorithm in Python or R for Landsat 7 ETM+

you could also check the Atmospheric and Radiometric Correction of Satellite Imagery (ARCSI) Python library, which supports a range of sensors, including Landsat 4,5,7 and 8. To complement the ...
dmci's user avatar
  • 4,902
7 votes

Sentinel 2A L1C product convertion from TOA reflectance to BOA reflectance

You'll need to run ESA's Sen2Cor algorithm to process Sentinel-2 Level-1C data to Level-2A. This will give you atmospherically corrected BOA data. If you then divide the values by the quantification ...
Val's user avatar
  • 273
7 votes

Calibrating Landsat Level-1 Precision and Terrain (L1TP) corrected data?

The three sensors are all slightly different. However the OLI/TIRs setup is a marked departure from the TM/ETM+ sensors. The changes are succintly summarised by Li et al. 2013 as the: replacing of ...
RoperMaps's user avatar
  • 2,166
6 votes
Accepted

Sentinel-2 images color cast

Blue color cast is caused by atmospheric scattering (= light reflecting off particles in the atmosphere is added to the light reflected from the ground), and it is always present in top-of-atmosphere ...
mkadunc's user avatar
  • 2,071
6 votes

Atmospheric correction algorithm in Python or R for Landsat 7 ETM+

In R, there are landsat package (CRAN) landsat provides basic tools for working with satellite imagery such as automated georeferencing and cloud detection. It contains functions for ...
Tung's user avatar
  • 409
5 votes

Sun glints and landsat 8 surface reflectance product

The Landsat 8 Surface Reflectance products are not sunglint corrected , so if your application is going to be adversely impacted by the presence of sunglints, then you should implement a suitable ...
Mikkel Lydholm Rasmussen's user avatar
5 votes
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Are landsat 8 SR and TOA rasters calibrated/corrected data or the data to be used for calibration/correction?

You will want to use the *_sr_band1 to band7 data for your analyses as these are atmospherically corrected surface reflectance products (Figure 1). Only the Surface Reflectance data products and ...
Aaron's user avatar
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5 votes
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What are the necessary correction/calibration on Landsat 8 imagery for land cover classification?

You can perform a land cover classification on a single Landsat scene without performing spectral and radiometric corrections. You will only need to do those corrections if you're trying to apply ...
Dan's user avatar
  • 1,100
5 votes
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Atmospheric effects on extracting soil from BSI index?

Bare soil and urban areas are notoriously hard to segregate. Even with a perfect atmospheric correction, there will be relatively high confusion between the two, particularly when limited to ...
jbukoski's user avatar
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4 votes
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Does RapidEye level 3A imagery need any kind of preprocessing before applying classification?

You need good reflectance values if 1) you want to measure some biophysical characteristics of the surface or 2) you want to generalize your approach over large areas. The radiometric corrections ...
radouxju's user avatar
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4 votes

Removing cloud cover using Sentinel Toolbox?

Yes, they are refering to atmospheric correction, to get Bottom of Atmosphere reflectance. The specific tool used for this is called Sen2Cor, which can be installed standalone or part of a package. ...
Roberto Ribeiro's user avatar
4 votes

Atmospheric correction algorithm in Python or R for Landsat 7 ETM+

I have also found a source code useful which is provided in RStoolbox package in R.Therefore I have attached the link here for other users and developers which might be useful for them as well. ...
morteza's user avatar
  • 303
4 votes

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

You do not need to do any further atmospheric correction with Landsat OLI/TIRS Level-2 data products as they are already corrected to surface reflectance. These data will be sufficient for time-series ...
Aaron's user avatar
  • 51.7k
3 votes

How to interpret 6S atmospheric correction results?

Yes it is rather commonplace to obtain some negative reflectances after atmospheric correction over dark surfaces. As said by Markus, this may result : from a too high aerosol optical thickness in ...
O. Hagolle's user avatar
3 votes

How to interpret 6S atmospheric correction results?

We just has a similar discussion in the GRASS bugtracker. It seems that a negative result may originate from visibility is assumed too low (optical thickness too high). See here for the reference: ...
markusN's user avatar
  • 13k
3 votes

How to find out whether a satellite image is atmospherically corrected

Well, one way would be to read the data documentation. The Scientific Data Hub specifically states: "The Sentinel-2 data offer for the Scientific Data Hub will consist of Level-1C user products", ...
Jeffrey Evans's user avatar
3 votes

How to find out whether a satellite image is atmospherically corrected

To put it bluntly, the best way is simply to look at the spectral bands of your Satellite image. If it has a near infrared band, the atmosphere should make a gap here in the case of an image without ...
Moreau Colin's user avatar
3 votes
Accepted

Dark Object Subtraction using Top of Atmosphere Reflectance?

Dark object subtraction is not atmospheric correction. It is image normalization. It is the simplest way of making two images acquired at different times, with different atmospheric conditions and ...
Mikkel Lydholm Rasmussen's user avatar
3 votes
Accepted

Why are colour distorted at large solar zenith angle in satellite image?

As you mention yourself, different wavelengths behave differently through the atmosphere. In theory, this can be counteracted through atmospheric correction, however, modelling the atmosphere ...
Mikkel Lydholm Rasmussen's user avatar
3 votes

Calibrating Landsat Level-1 Precision and Terrain (L1TP) corrected data?

Although the band specs are different for different Landsat sensors your answer depends on the product you're planning to use. The part you have copied and mentioned the "well-characterized radiometry ...
Ayda Aktas's user avatar
3 votes

Is atmospheric correction relevant for Landsat Level2 before classification?

As you can see from Landsat Collection 2 Level-2 Science Products, the level 2 Landsat 8 products are already corrected for radiometric, geometric and atmospheric effects. So to answer your question, ...
pan's user avatar
  • 567
2 votes
Accepted

Are Landsat 8 data from ESPA corrected and calibrated?

Yes, these are the Level 2 data products, which are calibrated to surface reflectance. These are able to be used for further analysis directly. *_01_T1_sr_band1 to band7 refers to the surface ...
Aaron's user avatar
  • 51.7k
2 votes

Age of RTK corrections - fixed solution accuracy

I have experience using RTK NTRIP corrections in the field, ideally, corrections should be less than 3 seconds depending on the application. Fixes every 10 seconds will be compromised depending on the ...
Elton Santiago's user avatar
2 votes
Accepted

Strips/scratches on PlanetScope imagery

There is not a single answer unfortunately. The satellites with the 0c prefix are getting on in age and sometimes exhibit artifacts. The UDM file signals which pixels have been detected as being ...
bosth's user avatar
  • 1,560
2 votes
Accepted

What are the available global GNSS corrections?

As far as I know, there is no real "global" system but their are different networks. From the government augmentation system, there is WAAS in North America, EGNOS in Europe, SDCM in Russia, BDSBAS ...
radouxju's user avatar
  • 49.8k
2 votes
Accepted

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

For the LS4-7 level 2 surface reflectance products which are supplied as Int16, you need to multiply the values by the scale factor 0.0001 to convert the values to 0.0-1.0. This is documented in the ...
user2856's user avatar
  • 67.2k
2 votes

Convert Planet Imagery Surface Reflectance product DN to surface reflectance values

The SR product is provided as a 16-bit GeoTIFF image with reflectance values scaled by 10,000. There is also a tutorial tutorial to convert MS radiance to reflectance.
mmann1123's user avatar
  • 591
2 votes

Sentinel 2 surface reflectance error Python code Google Earth Engine

As the error says, the max pixel's allowed is 10000000. You can change this to suit your data: image.reduceRegion({ reducer: x, geometry: x, scale: x, maxPixels: 1e9 });
aldo_tapia's user avatar
  • 13.7k

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