Rain calibration since firmware update v94

I’ve got false rain readings this morning. Got up at 530a and ground was dry… seems a little too windy to be a bird and the wind has not affected rain readings on the past.

@dsj Well the bug seems away well done !! Yesterday we had rain it was a frontal zone ( so no rain showers that can give local deviations)

The topo chart is from the Dutch KNMI these are handmeasured rainvalues by volunteers , they are verified. Measurements are always over 24 hours these are the measurements from nov 1st 8 UTC till nov 2d 8 UTC , I am located where the red spot is drawn , the rainfall was 5 mm in that timespan.

I’ve extracted the values over the same timespan from my weatherstaionsoftware (I’ve used local time UTC+1 for the same timespan. The sky sid measure 10.89 mm = 10.9 mm so I had about 2.2 more measured with the SKY , it’s improved but not yet good. I did not expect you can fix this so soon but thought it was a good idea to let you know my observations.

The coming days it will be dry so no rainfun have a nice weekend !
2 attachmenst rainchart KNMI and raingraph from my SKY.
rainfall
rain%20wf

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@dsj & @WFmarketing

Everything is spot on between my WeatherFlow SKY & AIR and Ambient Weather Osprey. My SKY is about two feet away from my Ambient Weather Osprey 2902. The AIR is about fifteen away direct line of sight from the SKY and Osprey. The data from both stations are trending very well side by side. My Osprey’s sensors are checked, calibrated if needed, every week to make sure they are working properly and to make sure the data is good. The Osprey’s barometer is calibrated to the local METAR - Andalusia/Opp Airport K79J.

If any data from my Ambient Weather Osprey can be used to help in my SKY & AIR’s calibration, then I wanted to let you all know of its availability. The Osprey has been online since June 2018.

Ambient Weather Osprey - Davis WXNet’s Osprey KALREDLE5

Keep up the fantastic work. :clap:

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Also if it helps to compare:
Davis VP2: https://www.wunderground.com/personal-weather-station/dashboard?ID=KCTSHERM2

Weather Flow: https://www.wunderground.com/personal-weather-station/dashboard?ID=KCTATCHI2

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@spacesnow Seems that my rain vallues where correct.

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@spacesnow I had in the same period 8.7 mm of rain, and you little map shows 5-6 (note that the map is from 8.00 till 8.00, but I added the amount together, so 8.7 from wf vs 5-6 from your map

Yes that map goes from 8 to 8 UTC thats how the KNMI measures when there’s no DLS as I said and those charts are mostly completed at the end of the day in the meantime they are provisional https://www.knmi.nl/nederland-nu/klimatologie/geografische-overzichten so you need the amount from your SKY from 9 to 9 (we’re in UTC+1) I think you had also to much rain registered.

A few days ago we had very light rain with mist coming in from the NE quarter - this was being driven with a wind of average speed of about 15km/hr. While we could see the rain, it was not being register by Sky. It appeared not to be working, but later as the rain became heavier and from the South the recording was working. It almost appeared that the wind was preventing measurement, maybe due to boundary conditions preventing the rain touching the sensor, and being carried over it.

To understand the rain “density” in Hamburg it would be called spu regen - in a word not much, can be seen and is rather wetting.

I would be interested in any comments.

You’ll find a lot of useful information in this thread: Rain calibration since firmware update v94

Two key points:

  • If the rain is too light (ie just misting) to cause a vibration it won’t be recorded. This is a known limitation of the haptic sensor.
  • The exact method you’ve used to mount your sky has an impact on its calibration, yet all sky units are currently using the same calibration. This is known to make some sky units over sensitive and some sky units under sensitive. WF is working on a calibration routine that will be applied to each sky unit separately, hopefully massively improving the performance of each individual unit.

Hope this helps :smiley:

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@peter,

Reading this post made me think.

If you look at WF roof top photos the array all have short poles to minimise vibrations.

At present all units calibrate the same while we await the CL roll-out. Given that all installations are different and given the longer the support pole the more likely there are vibrations that influence it, would it not be a good idea for users to have a slide to personalize the sensitivity of vibrations that affect the reading.

This would allow users to change the sensitivity (threshold) of the unit in order to disregard the likely / perceived disruption of vibrations. This would therefore also lead to the user comparing and localising comparable readings.

@dsj May be the CL program will do this by automatically by analysis

They all have short poles so they are easy to inspect and change out.

https://community.tempest.earth/t/rain-sensor-and-vibrations/1345/105?u=iladyman
To @14quaioui,
There is lots of discussion on the ‘Rain sensor and vibrations’ topic that explains the interactions between rain and wind.
cheers Ian :slight_smile:

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Yes, it will! The specifics of each SKY’s response will be accounted for by the CL process.

Rain results period Wednesday nov 7th 8 UTC till Thursday 8 UTC

Chart topo red dot is my location. Toatal rain measured by SKY 2.4 mm nov 7 till nov 8 UTC

Rain measurement nearest METAR 1.2 mm

Comparing charts added it seems WF overestimates about factor 2.1 not sure how much rain really was fallen on my location I think less as 1.4 mm this is about the same factor as in my previous observations https://community.tempest.earth/t/anybody-had-any-rain-since-firmware-update-v94/2266/163?u=spacesnow

Charts included rain%20wednesday%20thursday%208h%20utc%20till%208%20h%20urtc

rain%20wednesday%20thursday%20%20nearest%20metar%20graph

5%20mm

First two are official graphs from Dutch KNMI (Metoffice)
-Ron
More rain coming this weekend

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Here’s a summary of the last rainy days. My hub is at v98.
I’m very satisfied with my Sky. The final thing to fix is the wind speed when Sky is wet and find a better spot for my Air to avoid false lightning.
rain_comparison

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Values from another soaking overnight rain here in the North East US:

Rainwise #1 1.10" (WU station KMATOWNS8)
Rainwise #2 1.07"
Cocorahs 1.15" (station MA-MD-47)
Weatherflow .90" (WU station KMAWESTT16)

These stations are all within a radius of about 20 feet.

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Its firmware V98 and still too wet SKY measured today till this moment 7.1 mm rain
My raintip station measured 3.9 mm Nearest metar 3.8 mm no progress in callibration !?
rain%20saturday%20till%20now

I had a long duration rainfall today. the first 10 hours it was a moderate rainfall and my Davis VP2 and WF were within a .01 inch of total rainfall. The last three hours the rainfall has been light and very light. The Davis VP2 has .22 inches of rain more than the WF.
Seems in light and very light rain the WF doesn’t register much of the rain.

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station 4664
Sky over reporting rain in light and moderate falls
Sky 1.7mm
Rain gauge .8mm

It is currently raining here on mount Tzouhalem (Vancouver Island, British Columbia):

  • the Davis Instruments Vantage Pro2 shows the rain rate at 6.60 mm/h
  • the WeatherFlow shows the rain at ‘heavy’ (whatever that means!)

The WeatherFlow has been holding at ‘heavy’ for the last 15 minutes while the rain rate on the Davis Instruments Vantage Pro2 has varied between 2.4 and 7.1 mm/h.

Oops, the WeatherFlow has just changed to ‘moderate’ whereas the Davis Instruments Vantage Pro2 indicates a rain rate of 5.8 mm/h

The current cumulative daily rainfall for the WeatherFlow is 17.1 mm whereas for the Davis Instruments Vantage Pro2 is 14.2 mm.

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