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CFDoc
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- TL;DR Summary
- Uncertainty propagation, stochastic data, gradients of noise, overall uncertainty in mean values.
Hello all,
I've been on the hunt throughout the scientific literature for a little while now for some information, but I'm coming up empty. I'm hoping there's some expertise here in the area of altimetry as it relates to sea level calculations. More specifically, I'm trying to find the actual formulations, raw data filtering, and uncertainty propagation methods implemented in the global sea level average calculation.
My searching thus far has included reviewing the IPCC reports, Colorado State & Tolouse France journal articles, and JPL/NASA websites describing the TOPEX/Poseidon/Jason/etc. missions. However, the more scientific detail related information I am looking for has been difficult to come by. That is to say, I can't seem to find the more detailed information regarding how researchers took the instantaneous measurements over a given sampling period and calculated the low order moments reported in the literature.
For example, the JPL document for the TOPEX/Poseidon mission contains information regarding instrumentation used, orbital paths, and expected precision/accuracy of the instrumentation used. For sea level measurements, the instantaneous measurement shows an accuracy of +- 14cm.
See: JPL Poseidon Link
I am therefore taking this to mean that, in the raw data that would be a given sample in time, one would expect that measurement to be a distance measurement accurate to within +- 14cm. There are several other sources of error in the measurements such as orbit shifts/decays, atmospheric noise, etc.
However, when I read the documents discussing the average sea level height calculation during the TOPEX/Poseidon mission, I see accuracies listed as +- 0.1mm.
See: IPCC report
The information I can't seem to find is the detailed formulas used for (a) the ensemble mean calculations, (b) the propagation of all uncertainties throughout the dynamic period of sampling, (c) the justification for how instrumentation with accuracies on the order of tens of centimeters can yield low order moments on the order of tenths of a millimeter, and (d) how gradients of stochastic samples are somehow reducing, not increasing, the overall uncertainty in the calculated statistics.
For (d) I am referencing the rate of changes and accelerations being reported to the hundredths and thousandths of a millimeter, respectively.
If anybody knows where I can find this information and read these papers, I would appreciate it.
Thanks in advance.
I've been on the hunt throughout the scientific literature for a little while now for some information, but I'm coming up empty. I'm hoping there's some expertise here in the area of altimetry as it relates to sea level calculations. More specifically, I'm trying to find the actual formulations, raw data filtering, and uncertainty propagation methods implemented in the global sea level average calculation.
My searching thus far has included reviewing the IPCC reports, Colorado State & Tolouse France journal articles, and JPL/NASA websites describing the TOPEX/Poseidon/Jason/etc. missions. However, the more scientific detail related information I am looking for has been difficult to come by. That is to say, I can't seem to find the more detailed information regarding how researchers took the instantaneous measurements over a given sampling period and calculated the low order moments reported in the literature.
For example, the JPL document for the TOPEX/Poseidon mission contains information regarding instrumentation used, orbital paths, and expected precision/accuracy of the instrumentation used. For sea level measurements, the instantaneous measurement shows an accuracy of +- 14cm.
See: JPL Poseidon Link
I am therefore taking this to mean that, in the raw data that would be a given sample in time, one would expect that measurement to be a distance measurement accurate to within +- 14cm. There are several other sources of error in the measurements such as orbit shifts/decays, atmospheric noise, etc.
However, when I read the documents discussing the average sea level height calculation during the TOPEX/Poseidon mission, I see accuracies listed as +- 0.1mm.
See: IPCC report
The information I can't seem to find is the detailed formulas used for (a) the ensemble mean calculations, (b) the propagation of all uncertainties throughout the dynamic period of sampling, (c) the justification for how instrumentation with accuracies on the order of tens of centimeters can yield low order moments on the order of tenths of a millimeter, and (d) how gradients of stochastic samples are somehow reducing, not increasing, the overall uncertainty in the calculated statistics.
For (d) I am referencing the rate of changes and accelerations being reported to the hundredths and thousandths of a millimeter, respectively.
If anybody knows where I can find this information and read these papers, I would appreciate it.
Thanks in advance.