Questions tagged [reflectance]
Reflectance is the ratio of incident flux and reflected flux from a surface
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Seeking Ocean RGB Reflectance Dataset
I am looking for a dataset of ocean reflectance.
I am building some ML algorithms and I need RGB "ocean satellite images".
I tried using the Landsat 8, and Copernicus datasets in Google ...
0
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1answer
41 views
Cloud masking the Landsat-8 Surface Reflectance product without using GEE
I have a collection of Landsat8 Collection2 Level2 images (surface reflectance) and I would like to cloud mask those images somehow, so I can further make a time series of NDVI and other remote sensor ...
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23 views
GEE ：Cloud/Cloud Shadow Masking for Landsat TOA Data
Due to data limitations, I need to use TOA data to extract cloud shadows instead of SR data. Is there any good way?
In addition, why is the amount of SR data less than that of TOA?
and this is the ...
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24 views
Spectral Profile Chart Using Landsat 5 TOA Earth Engine
I'm attempting to create a spectral profile chart for 4 features in my feature collection that represent vegetation. I'm not really sure how to move forward, this is one of my first few times coding ...
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How to get right reflectance from Sentinel-2 LIC images?
I found that the range of DN from Sentinel-2 images is 0 ~ more than 10000. How can I get reflectance(0~1)?
This picture showed the way to get reflectance. But in this way, reflectance will over 1. ...
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24 views
How is Band 8 (panchromatic) of Landsat connected to Surface Reflection/Albedo?
I want to work with the surface reflection/Albedo of Landsat 8 and got told to use B8 which is the panchromatic. It catches all the visible light so it makes sense to me that it is connected but I ...
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1answer
53 views
Limiting cloud estimation of Landsat8_SR over ROI in GEE
I intend to create an image collection of Landsat-8 surface reflectance not TOA that has 100% free cloud over my Region of Interest (ROI). Not surprisingly the code I have found in the forum ( Filter ...
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1answer
141 views
Correcting Worldview-3 data to ground reflection/bottom of atmosphere with open source?
I have some worldview-3 imagery that needs to be corrected from digital numbers to actual reflection values (preferably bottom-of-atmosphere). But the tricky part is I am looking for open source ...
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179 views
Rescaling Landsat-8 SR to surface reflectance
I want to rescale the Landsat-8 SR image using the rescale factor in the documentation, which is 0.0001 for each band. I assume that the original values are DN values, and after rescaling I can get ...
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1answer
54 views
NDVI out of range?
I have composed a mosaics of 3 images of Landsat 8 Surface Reflectance Level 2 for the bands NIR and RED. According to the Landsat Surface Reflectance Product Guide each band is supposed to be ...
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1answer
45 views
Explanation on band conversion from radiance to reflectance final value
I've watched few video on conversion of radiance to reflectance for landsat band, most of them recommended to use formula below to to make sure the final reflectance value lies in between 0 to 1. My ...
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Extraction of reflectance value in ERDAS Imagine
How can I extract the reflectance value from a raster in ERDAS Imagine. If possible I would like to know the steps.
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1answer
43 views
Understand values for Landsat 8 surface reflectance image
What do the numbers represent when you download an image, in my case Landsat 8 OLI TIRS surface reflectance.
Are they DN numbers or reflectance values?
If the image is not surface reflectance product, ...
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1answer
259 views
How to apply a Bitmask for radiometric saturation QA in a image collection (earth engine)
I am new to earth engine and I am trying to apply a radiometric saturation mask in a image collection based on ''radsat_qa'' in earth engine data catalog for landsat reflectance tier 1.
I am trying ...
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213 views
PlanetScope NDWI calculations
I am trying to calculate NDWI for a PlanetScope image scene. I currently have 2 products: one is the "3B_AnalyticMS_SR.tif" and the other is the "3B_AnalyticMS.tif" product. I believe the former is ...
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80 views
Implementing BRDF in R
I use UAS to survey vegetation at subcentimeter resolution for my research and have found that bidirectional reflectance (BR) is a huge issue that impacts the reliability of estimates across ...
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72 views
Calculation of TOA radiance from Sentinel-2 1C product reflectance
I was trying to convert the Sentinel-2 1C product to radiance and came across two links first once says
radiance = ((pixelValueBandX * cos(incidenceAngle) * solarIrradianceBandX) / (pi * d2)) / ...
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0answers
66 views
Calculating Reflectance from Parrot Sequoia DN
I am dealing with the images of a Parrot Sequoia. I could not pre-process the images in Pix4d because I took single shots in different parts (so there are not overlapping images).. for me it is ...
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1answer
47 views
Comparing Landast 8 Images?
I'm currently working with Landsat 8 OLI/TIRS Level-2 Data Products - Surface Reflectance and I would like to compare different landsat images from different places on earth. I was wondering if pixels ...
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2answers
438 views
Conversion of Landsat ToA reflectance to BoA reflectance with an equation
I am using temporal datasets from Landsat 5, 7 and 8.
Since I have many datasets I would like to include the conversion from ToA(top of atmosphere) to BoA(bottom of atmosphere) reflectance into a ...
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1answer
194 views
Converting Landsat8 DN to TOA reflectance using GEE manually
I'm fairly new in Google Earth Engine and JavaScript. I'm trying to convert Landsat8 DN to TOA reflectance using GEE using a function.
// Load a raw Landsat scene and display it.
var image = ee.Image(...
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1answer
37 views
Blank table when exporting a feature selection of a image collection
I'm trying to get reflectance data of some points that i've gotten from another database through a Json table of pings.
I've used this code to get the data but returns only the title of columns with ...
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2answers
913 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 ...
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1answer
586 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 ...
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51 views
How to Correct Landsat 8 Imagery with TOA Reflectance >1 and <0?
I recently downloaded Landsat 8 T1 imagery and have ran into some difficulties during pre-processing. I applied the TOA reflectance and sun elevation corrections to Bands 2,3,4,5,6 using ArcGIS's ...
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1answer
1k views
Converting Digital Number (DN) to reflectance in order to analyze NDVI
I'm working with a mapir nir + red camera meaning that its blue band captures nir light and its red captures red normally. I understand that NDVI is calculated using reflectance values.
How do I ...
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1answer
582 views
Radiometric, reflectance and atmospheric correction for Landsat 8 image
I am struggling with the pre-processing process for landsat8 imagery.
I want to use some indices (e.g. NDVI, SAVI, EVI, NDMI) and create a land cover map at the end using ENVI and ArcGIS.
As a ...
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1answer
1k views
LiDAR returns over water bodies?
I have obtained LiDAR data from my environmental agency in order to obtain the relative heights of each watercourse station. A far as I know, LiDAR signals do not get returned over water bodies. ...
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2answers
107 views
Why reflectance map in pix4d dont are normalized
I want to know, why my reflectance map, dont have value between 0 and 1. Because my calibration table said me: for example red band has max value = 0.88 nm, and my reflectance map in red band have max ...
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0answers
83 views
Set multiple values to nodata - Erdas Imagine 2015
I am having trouble with the data ranges in the Landsat 8 surface reflectance product which I downloaded from USGS. The Lansat 8 surface reflectance handbook says the valid range is 0 - 10,000 range ...
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1answer
155 views
I can apply tasseled Cap transformation in surface reflectance (not ToA)?
I can not understand if I should adjust the Tasseled Cap index with the surface reflectance values or the Top of Atmosphere
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124 views
When to rescale reflectance data to calculate vegetation indices
I'm attempting to calculate a number of vegetation indices using hyperspectral AVIRIS data in ENVI. Some of these indices are normalized, such as NDVI, whereas others are not, such as the Transformed ...
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1answer
201 views
Negative Surface Reflectance
I am using Landsat Surface Reflectance Level-2 images. I have to convert the DNs to reflectance values. When I apply the formula provided in the Landsat8 User Handbook :
reflectance = ...
3
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1answer
409 views
Landsat8 surface reflectance rescaling pixel
Sorry for this basic question, but I am using Landsat8 images with "surface reflectance" treatment from Landsat8.
I am having some trouble with the data from some bands. Most of pixel are beyond 10k.
...
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1answer
90 views
Obtain reflectance map in pix4d?
I can not obtain my reflectance map in pix4D.
The program said:
Unable to computed radiometric calibraticon from sequoia. Unable to
computed coordinated system.
Its rare, because normally i ...
2
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1answer
3k views
How to get property of each image in a collection in google earth engine?
I am trying to convert ASTER image from DN values to reflectance. For this I require gain coefficient of each image in the collection I have gathered.
//Defining geometry
var geometry = ee.Geometry....
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1answer
594 views
Are landsat 8 SR and TOA rasters calibrated/corrected data or the data to be used for calibration/correction?
I downloaded Landsat 8 Level-2 scenes from https://espa.cr.usgs.gov/ for land cover classification. Following are the product list in the package, cause I ticked Top of Atmosphere Reflectance (TOA), ...
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1answer
623 views
What are the necessary correction/calibration on Landsat 8 imagery for land cover classification? [duplicate]
I downloaded calibrated/corrected Landsat 8 data (Level 2) from ESPA (https://espa.cr.usgs.gov/) to do land cover classification. But there are many corrections and calibrations can be done as listed ...
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1answer
155 views
Surface reflectance product - do I always need it?
There is a neat Surface Reflectance product of Landsat imagery. I know the difference between SR and raw products: SR presents calculated values, that are supposed to represent state of the Earth ...
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1answer
838 views
Negative values in Landsat 8 surface reflectance higher level product
I have downloaded Landsat 8 higher level surface reflectance product from USGS to genetare chlorophyll map in lake. But the individual bands contain some negative surface reflectance values. So, when ...
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0answers
834 views
Calculate reflectance for UAV images
I have high resolution images captured by a drone using a , they are RBG and NIR images. My question is how can I calculate the reflectance for the images, the values are currently in digital numbers (...
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1answer
390 views
Whole image cloud cover for LC8_SR?
I need to filter the LANDSAT/LC8_SR image collection using an assessment of total cloud cover in the entire scene of each image. i.e. each image in the collection is "in" or "out" based on a ...
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1answer
2k views
Sentinel-2 Reflectance calculation
What is the procedure for reflectance calculation from Sentinel 2 1C products downloaded from ESA Scientific Hub?
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1answer
232 views
Landsat 7 - 8 surface reflectance bands from ESPA (LEDAPS)
I have downloaded some Level 1 and higher level imagery data including surface reflectance as well.
I should process these data in Idrisi (Selva) package.
The Level 1 images' pixel values are between ...
3
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2answers
388 views
Strange reflectance values in Sentinel-2 images over sea ice
I am dealing with Sentinel-2 (Level 1C) images over sea ice. I have downloaded some and was wondering: When I look e.g. at Band 8A, there are some images where the reflectance over the water between ...
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1answer
2k views
Calculating Albedo for Landsat 8 using QGIS with GRASS?
I am trying to estimate albedo for Landsat 8 OLI. The idea was to use the GRASS function i.albedo within the processing toolbox of QGIS. However, the option for Landsat 8 OLI is not available, ...
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1answer
100 views
Very low reflectance values landsat 7
I am getting very low reflectance values (mostly < 0.15) in all bands of multiple Landsat 7 scenes after having converted to TOA reflectance manually in ENVI. These values are not supposed to ...
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1answer
4k views
What is the range of values of Sentinel-2 Level 2A images?
I found in Level 2A Product Format Specifications Technical Note page29 that:
"The L2A Quantification Value is aligned with the L1C Quantification Value of the L1C product from which the L2A product ...
0
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1answer
121 views
A method to match narrow bands from in-situ spectrometer with Landsat-8 central band
Is there a way to resample Landsat-8 bands to match different bands from a spectrophotometer. I'm doing atmospheric correction, comparing in-situ reflectance measurements performed using 10-nm wide ...
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2answers
249 views
Sentinel-2 images color cast
I work with Sentinel-2 images (Level-1C products (top-of-atmosphere reflectances)). I would like to know why some of the images do have this blue(?) undertone/color cast. I think those images are from ...
