I know this is an older topic but I have a few thoughts I'd like to share in regards to "peak wind" with both the Davis mechanical and ultrasonic anemometers.
TLDR #1: The ISS ID # and associated delay doesn't really cause any data to be lost but if you care about "peak wind" and short gusts should probably still aim for anemometers to be on the lowest ID # possible.
TLDR #2: Sonic anemometers are not really better at recording short gusts and "peak wind" than mechanical anemometers unless you have a large power budget that allows a high sample rate.
Yes that seems to be the picture. When you really start to look at the detail then one or two wrinkles appear like the difference you've highlighted between the 2.25sec and the 3sec (if you had an anemometer on ID #8) periods. AFAIK these aren't explained in any technical documentation that I'm aware of.
I can't speak for older ISS firmware but the current ISS firmware appears to adjust the sample period based on the ISS ID. Basically, ID #8 results in a longer sample period than ID #1. I'm working on an adapter for 3rd party serial and 0-5v anemometers and the gap between sample periods stays constant regardless of ISS ID #.
That said, I still recommend setting any ISS transmitting wind data to ID #1 if short gusts and "peak wind" is something you care about. The reason for this is that the higher the ID and the longer the sample period, the more quick gusts will be washed out by averaging.
Time remains a variable even with Ultrasonic and most conform to WMO standards.
Like in the case of some Ultrasonic sensors, wind Gust is the highest 3 second average of the wind speed within the last 10 minutes with the 3 second averages based over 250ms values with the values updated/outputted as some additional time interval. This thinking that somehow anemometers measures instantaneous wind speed somehow in real time is totally false ... again and always will be
People definitely tend to put sonic anemometers up on a pedestal for all the wrong reasons. Unless you have a large power budget, they are not going to be any better at detecting "peak wind" and short gusts than most mechanical anemometers. Most all of the higher end sonic anemometers allow you to adjust both the output interval (or you can opt to poll the sensor) *and* the samples taken for each interval/request. The more samples, the higher the power draw. Now here's the kicker, most of these sonic anemometers do not spread the samples out over the output interval and do not have an option for this as this would prevent the sensor from sleeping between sample periods to save power. The output interval is basically just an auto poll/request and each X seconds the sensor will take X samples and output the average. You can almost always find the time it takes for a single sample in the documentation and adjust the number of samples per interval to almost max out the interval period. However, this comes at the cost of more power draw.
What does all of this amount to? Let's say we have a sonic anemometer than can take 200 samples per second and the output interval is set to 2 seconds but due to available power limitations you only have it taking 16 samples (real world example with 16 being the default). Unless you *know* that sensor spreads out the samples over the output interval or it has an option to do so, the gap between samples periods may result in short gusts and "peak wind" not being captured.
To bring this back to something applicable with Davis systems... The solar powered LCJ/Davis sonic anemometer has a update update frequency of 1 second as mentioned in the documentation. Basically, it updates the pulse frequency sent to the ISS once per second. What is *not* known is the number of samples and the sample period. With the limited amount of power available, I doubt the numbers are impressive which would mean it's fine for average wind speed but may not be ideal for people interested in peak wind.