difference windspeed Davis console - MB PRO

[ws-kaiserville]

I see that the reading of wind speed is different when looking at the console from Davis and what the PRO2 is reading. The Vantage pro is fairly new (from early 2025) and sends decimal wind speeds to the console in contrary to the older generations. The meteobridge (using the RF receiver) seems to interpret the signals in the old fashion with increments of about 1,8 km/h. It also seems the wind speed of the VP console is somewhat higher on average (like 5-10% if I check 10 minute averages), although the difference is not a fixed value or percentage. Individual readings can sometimes be lower on the console (I sometimes see that in the gusts) but most often higher, sometimes by more than 10%.

It's not really disturbing since wind speed within a village will never be like on an official site, but still I'm wondering if anyone else noticed this, or if there is already an update on this part foreseen in the future?

[admin]

The ISS is sending windspeed in mph via RF without decimals. The decimals you see when converted into m/s or km/h in the display are giving you the false impression of being more precise.

Nevertheless differences can show up when PRO2 or console miss RF packets.

What is the reception rate of the PRO2? Which RF threshold did you define? Those have an impact to avoid loosing any ISS packet.

[Mattk]

.... The Vantage pro is fairly new (from early 2025) and sends decimal wind speeds to the console in contrary to the older generations....

Have never seen anything to the contrary where the Davis ISS specifications have changed, can you provide the Davis source in that regard?

The latest Davis spec sheet states resolution and units as Measured in 1 mph with other units converted from mph and rounded to nearest 1km/h, 0.1m/s or 1 knot with an Accuracy of +/- 2 mph (2 kts, 3 km/h, 1 m/s) or +/-5% whichever is greater and that has been and continues to be the case to this days as far as I am aware? if you have new details then please share?

Where Davis consoles can vary is how they handle the incoming ISS data which is all the same to all units. Davis differentiate between between small & large cups and treat the Vue ISS differently again. As such a VP2 console needs to be told if the anemometer is a VP2 or Vue or other (like an Ultrasonic) etc. An Ultrasonic is believed not to require any corrections as might be applied to a VP2 cup anemometer with solid state magnetic sensor?

Different Davis consoles with different firmware can show wind speed differences due to the inherit Look Up Tables which supposedly correct the raw wind speeds relative to wind direction angle of attack on the anemometer head/body but this is something that Davis has never released.

MB's I don't believe differentiate between cup size and/or Ultrasonic etc and if under the +/- 2 mph then it all becomes rather speculative especially considering non conforming Davis anemometer setups which many consumer setups are.

[ws-kaiserville]

I don't really have a Davis source, but I can see it on my console that wind speeds like 0.8 km/h or 1.1 km/h are shown. There are however also others on wxforum who noticed the same behavior and did some investigation around it. See in this thread. It seems like this is added in more recent transmitters.
The humidity also has a resolution of 0.1%, but the accuracy of that sensor is too low for that having any value.

Just to be clear: the console of my VP station is the new WL console. On the old VP1 I have had for over 20 years, the resolution was indeed 1 mph.

The sensitivity of the PRO2 is set to -90dB for the transmitters which have a not so strong signal. The anemometer has the strongest signal (-65 to -60 dB usually) and certainly has >90% reception. In a rare case I can have a wrong wind speed reading (probably RF interference), only happened twice in 1.5 years.

[admin]

May be the new WL console does some averaging on the wind data and generates more decimals by that. Meteobridge reports the RF data from the ISS as it comes.

[ws-kaiserville]

According to the WXForum topic it depends on the firmware of the transmitter, since with older transmitters the WL console also shows the classic whole integers in mph. So if I have to believe that, then not every transmitter says the same, newer ones send extra information (probably since late 2024 or early 2025). Luckily they built it backwards compatible (otherwise they would have had many angry owners of the older type of console by now )

As I say: it's not really important because the accuracy is too low to be bothered by 0.1 or 1 mph. It is just something I was wondering about.

Another difference I see is that sometimes the humidity is dashed out on the console for a short period (worst case 20 minutes), while the MB Pro keeps giving a value for humidity (although it doesn't change as long as the value on the console is dashed out). In this case I like the behavior of the MB Pro more. Also a somewhat weird difference.