All Questions
15 questions
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35
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How to the image date/ metadata used when using the .median filter in GEE?
I am processing LST, NDVI, NDBI, & UHI data in a 1 year period. I used the .median filter function for filtering the dates.
My question is, how do I know what images to use? I've tried the ...
1
vote
1
answer
117
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Google Earth Engine Landsat NDVI
I'm trying to map deforestation using Landsat NDVI time-series. But unfortunately I can't find the data from 2022 - 2023, on the other side data before that year is available. Can someone explain me ...
- 31
0
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1
answer
285
views
Get monthly NDVI and NDWI median for a year, from Landsat collection Google Earth Engine (GEE)
I am trying to get NDVI and NDWI per month, based on the median of the images in one month. For this, I am using Landsat8 collection an year 2018. I keep getting empty bands for the var monthlyStats. ...
0
votes
1
answer
52
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Visualize mean NDVI for the past 4 years Jan to Dec to distinguish cropland in GEE [closed]
My goal is to perform supervised classification in a large area using Landsat 8 images. Since the area has a lot of vegetation, it is challenging to accurately distinguish agricultural areas. To make ...
user226282
0
votes
1
answer
35
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NDSI handling of areas that cross over a pixel
I am using GEE to calculate the NDSI on Landsat8 using a polygon area of 500m.
Since Landsat8 has a 30m pixel resolution, I wondered how the partial pixels are handled in the calculations.
Are they ...
-2
votes
1
answer
193
views
Extraction of NDVI values against each GPS coordinates of Landsat 8 images
My goal is to calculate the NDVI value of each image from 2017 to 2022 but output values show the same value for each image.
Can you look at the code?
var Date_Start = ee.Date('2017-01-01');
var ...
1
vote
2
answers
197
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Extracting NDVI and EVI in Alaska (EVI is showing -2 to 2 values)
I am working on extracting NDVI and EVI across the Landsat 8 collection in Alaska. Everything seems to be going swell, except the calculated EVI values are going from -2 to 2 instead of -1 to 1. I ...
3
votes
2
answers
748
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Forcing y-axis range in ui.Chart.image.series()
I am harmonizing Landsat 8 and Sentinel-2 datasets for agricultural mapping purposes. When plotting the results using ui.Chart.image.series function, one graph shows the y-axis starting not at 0. For ...
- 568
0
votes
1
answer
406
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Creating NDVI time series graphs from buffered point (vegetation plot) locations in Google Earth Engine
I am aware there are a lot of similar questions to this on here like
Time series analysis of NDVI using Google Earth Engine
Creating NDVI time series from single polygon of shapefile using Google ...
1
vote
0
answers
161
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Quarterly composites for calculating NDVI and EVI
I am trying to create a code that could be helpful for making quarterly composites from 2013 to 2016 in order to calculate NDVI and EVI.
I have figured out this code:
var start = ee.Date('2013-01-01');...
- 75
1
vote
0
answers
63
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How to add different NDVI layers of Landsat 8 data from 2014 to 2019 to a map in Google Earth Engine?
I am trying to calculate NDVI for each month and masking NDVI images with lte(0) filter to identify water bodies and show the timelapse between encroachment area of waterbodies in different years and ...
- 11
3
votes
1
answer
1k
views
Different min and max NDVI values with different approaches using Google Earth Engine
I'm trying to calculate the vegetation fraction for land surface temperature calculations of a single Landsat 8 image. I need to find the min and max NDVI of the scene.
I've masked the image and ...
- 674
4
votes
2
answers
5k
views
Smoothing/interpolating across images in an ImageCollection to remove missing data
I have some code that is working properly to calculate the monthly NDVI averages for the previous two years from a date but I sometimes have missing data in some of the months and I would like to get ...
- 419
5
votes
1
answer
1k
views
Black vertical lines on exported image from Google Earth Engine
I tried to export the NDVI obtained from the Landsat 8 Surface Reflectance Collection in Google Earth Engine and I keep on getting black lines in my final export. Everything looks fine when displaying ...
- 63
1
vote
0
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784
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How to export image on google earth engine for large area?
The area that i have been work have about 159695,938 km² and I am mapping the deforestion on this with NDVI. I had to use 2 years to remove all the clouds (eg. 2015-01-31 , 2016-12-31) using a reducer....