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I want to run a classification application but feed it with time series data of Landsat imagery. I have a set of points (each point has an attribute of 'class') and an image collection LandsatCol. For my task, I need to extract time series of Landsat band values for each point over whole image collection, then make dataset of these sequences and their associated labels. What I was doing before was to first do a map and sampling in GEE as follows:

var LandsatSeries = 
    LandsatCol.map(function(image) {
      return image.sampleRegions({
        collection: points,
        properties: 'class',
        scale: 30
      });
    })

Then for each feature in the resulting feature collection I added an ID and also a date (using its system:index field) and exported the resulting 2-D table (band values as columns, each point in each image as rows) out of GEE. Then I had a second Python script to read the table and reorganize it to a 3-D dataset (points as first dimension, sequence time as the second dimension, and band values as the third dimension). Then I split it to training and testing partitions and do my classification.

But as my number of points grow, I am now thinking if there is a more efficient way of doing it but I couldn't find a clue how to define a map function over a collection to extract the time series for each point separately and wrap them in a 3-D feature collection directly. I also played a little with iterate function but I was not successful.

Any idea?

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