CODEWITHSUNDEEP
pythongoogle-earth-engine
XIN
XIN

Reputation: 1

GEE:how to understand the parameter 'SCALE' in FUNCTION 'ui.Chart.image.series'?

print(ui.Chart.image.series(col, geometry,ee.Reducer.mean(),20).setOptions({
title: 'TimeSeries analysis',
lineWidth: 1,
pointSize: 3 }));

enter image description here

print(ui.Chart.image.series(col, geometry,ee.Reducer.mean(),200).setOptions({
title: 'TimeSeries analysis',
lineWidth: 1,
pointSize: 3 }));

enter image description here

when I set the parameter scale in different values, the chart is different(I mean at the same time while the value is different), so I want to know the meaning of the "scale" parameter and ee.Reducer parameter? I try to find the meaning in the GEE guide help, but can't understand.

Upvotes: 0

Views: 1034

Answers (1)

MadeleineN
MadeleineN

Reputation: 148

Scale refers to the pixel resolution used to analyse the image. The larger the scale the more aggregated the pixels will be, thus outputting different results. Say you are analyzing a vegetation index on a plot of land. If you want to know the max value, analyzing it by pixels of 20 m by 20 m will lead to a different result than if you analysed it in pieces of 1000 m by 1000 m. The smaller the resolution, the more accurate the results, but the slower the calculation and vice-versa.

More info on this here https://developers.google.com/earth-engine/guides/scale

Upvotes: 1

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