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How to calculate NDVI time series using Landsat 7?
I want to to calculate NDVI time series from 2015 to 2018 using Landsat 7 and get the maximum NAVI value in this period and it’s corresponding image index. That is, the horizontal and vertical axes value of this picture, I want to get the Image index in Google Earth Engine, not the time. To get the maximum ndvi you could use qualityMosaic function.
How to create NDVI time series in Google Earth?
I am exploring Sentinel-2 time-series NDVI with Google Earth Engine. In another post ( here) I calculated and exported NDVI values from Sentinel-2. Now I would like to create a NDVI time series chart, but when I run the code (see below) I get
What are the time series of Landsat sensors?
This time period is covered by 3 Landsat sensors: Landsat 5, Landsat 7 ETM and Landsat 8. We need to combine these. Landsat 7 ETM suffered a scan line failure in 2003. You can read about it here. Landsat 8 has different band numbers. Band 1 in Landsat 5 and Landsat 7 ETM is blue; in Landsat 8 Band 2 is blue.
How is Google Earth Engine used for Landsat data?
Thesis, the Google Earth Engine (GEE) is used to extract NDVI data from Landsat 5 and Landsat 7 satellite images. The NDVI data is then processed and visualized using R. GEE and R code, as well as the NDVI data, is available here and can be reused or be easily adapted by others.
How to calculate the vegetation index on Landsat?
Landsat Surface Reflectance-derived Normalized Difference Vegetation Index (NDVI) Specifications Attribute Value Long Name Normalized Difference Vegetation Index Short Name LC8NDVI, LE7NDVI, LT5NDVI, or LT4NDVI File Name *_sr_ndvi.tif Data Type Signed 16-bit Integer
How to calculate the maximum NDVI time series?
To get the maximum ndvi you could use qualityMosaic function. To be able to know which image ID the pixel comes from is more complicated because as it is not a numerical property, you have to encode it some how. This is how I’d do it, but it’s just one way, there could be other ways (may be easier)
What is the normalized difference vegetation index ( NDVI )?
The Normalized Difference Vegetation Index (NDVI) is a quantitative index of greenness ranging from 0-1, where 0 represents minimal or no greenness and 1 represents maximum greenness. NDVI is often used for a quantitate proxy measure of vegetation health, cover and phenology (life cycle stage) over large areas.