Weather Station Hardware > Hydreon RG-11 Optical Rain Gauge/Sensor

RG11 as a rain rate/intensity detector

<< < (2/7) > >>

Exactly... That's why one of the parts of this experiment is to divide the drop count by the rain gauge reading (currently 0.0001" TB emulation), to see how many drops make up each tip.

Here's a chart of drops per tenthousandth from that sample data.

Keep in mind that the base data was recorded every 60 seconds so this is 15 minutes of samples

I talked with Hydreon a while back and they either didn't know or wouldn't tell me what the effective aperture or effective surface area of the sensor is, so I could use that to calculate drop volume. So, I'll have to measure or calculate or estimate it.

Due to the admitted inaccuracies of the units, I'm not really sure if the outcome will be useful or not. I suppose I will have to try to compare results with perceived drop size.

And, not knowing the underlying algorithms Hydreon uses, I wonder about any "self-referential" error that might creep in. I believe it has some finite integration time, because sometimes on the TB unit, I would get 2 quick clicks in a row, like it was trying to catch up. 

--- Quote from: Old Tele man on November 02, 2016, 10:03:49 AM ---Rain *amount* is measured in VOLUME...cubic inches per square-inch per unit time...however, each falling rain drop has multiple characteristics: (1) physical size/volume, (2) velocity, and (3) impact rate. Also, at the cross-over from water into ice, even #1 physical size/volume changes!

--- End quote ---

Over the last few days, I finished setting up my rain lab, installing the cabling, and getting the logging programming written just in time for some rain yesterday.

This is from 10:21 until about 19:00 yesterday, Sunday. I logged the counters from the RG11 in drop counting mode and ten thousandths TB mode. The I opened the CSV file in LibreOffice Calc and subtracted subsequent readings from the previous one to get drops or ten thousandths per minute and graphed it.

It shows pretty clearly the waves of rain going through.

Old Tele man:
What does the preliminary mathematical correlation analysis look like? R2 > 0.90?


--- Quote from: Old Tele man on November 21, 2016, 02:44:32 PM ---What does the preliminary mathematical correlation analysis look like? R2 > 0.90?

--- End quote ---

Correlation of what to what?

Actually, I'd like to compare it to a tipper, but right now I have a problem.

The RG11 data is "synchronous". That is, the numbers come in so fast that I record the totals once a minute.

However, the 0.01" tippers are "asynchronous". They are comparatively so slow that I record the seconds between individual tips, and, last rain, didn't record the time stamps for each tip.

So, I need to time stamp that data, or otherwise figure out how to compare the 2 data sets.

Old Tele man:
As a "first-cut" analysis: what's ORANGE line vs. BLUE line (and vice-versa) look like? Somewhat linear or just a 'cloud' of dots vs. dots?


[0] Message Index

[#] Next page

[*] Previous page

Go to full version