0
$\begingroup$

I have a time series of remote sensing observables. For example, the observed brightness from 2007 to 2019. And we have 2 datapoints per day. How can I calculate the interannual variability of this variable? and the seasonal amplitude? and how to define them? I want to study the relationship between interannual variability and seasonal amplitude of this variable. It's better to do a scatter plot with X-axis as interannual variability and Y-axis as seasonal amplitude. But I have no idea about the definition and the calculation of inter annual variability and seasonal amplitude (and also seasonal variability). I am a beginner, is there anyone who can help me? thanks a lot!

$\endgroup$
0
$\begingroup$

In what context are these terms? Surely they must be defined somewhere if needed. If you thought about them, then their definition is up to you.

"Inter-annual variability" doesn't tell much. It could be the variance between yearly averages, i.e. the average of the variance within year 1, variance within year 2 etc. but that would give you only one number. Or it could be the year-over-year variance, i.e. the variance of: variable at day 1 year 1, day 1 year 2 etc., like stock returns (though I don't see this making much sense here). It may make more sense to get the "intra-annual variance" here, i.e. the variance of the variable within a year.

"Seasonal amplitude" is just as vague. Could mean the absolute distance of the most extreme value observed (negative or positive) from the mean of that year/season. Or it could mean fitting a Fourier series (a sine or cosine curve may do) for each year/season and calculating the magnitude of the amplitude of the wave.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.