Received: from opus.hpl.hp.com by jr.hpl.hp.com with ESMTP (1.37.109.24/15.5+ECS 3.3+HPL1.1) id AA172080264; Wed, 21 Jul 1999 11:04:25 -0700 Return-Path: <harris@Synopsys.COM-DeleteThis> Received: from hplms26.hpl.hp.com by opus.hpl.hp.com with ESMTP (1.37.109.24/15.5+ECS 3.3+HPL1.1) id AA197640250; Wed, 21 Jul 1999 11:04:10 -0700 Received: from hamachi.synopsys.com (hamachi.synopsys.com [204.176.20.26]) by hplms26.hpl.hp.com (8.9.1a/HPL-PA Relay) with ESMTP id LAA09014 for <wind_talk@opus.hpl.hp.com-DeleteThis>; Wed, 21 Jul 1999 11:04:08 -0700 (PDT) Received: from marathon.synopsys.com (marathon.synopsys.com [146.225.100.41]) by hamachi.synopsys.com (8.8.8/8.8.5) with ESMTP id LAA09116; Wed, 21 Jul 1999 11:00:22 -0700 (PDT) Received: from synopsys.com (dhcp-146-225-75-129 [146.225.75.129]) by marathon.synopsys.com (8.8.8/8.8.8) with ESMTP id LAA20850; Wed, 21 Jul 1999 11:00:20 -0700 (PDT) Message-Id: <37961884.D862477F@synopsys.com-DeleteThis> Date: Wed, 21 Jul 1999 10:59:17 -0800 From: Greg Harris <harris@Synopsys.COM-DeleteThis> Organization: Synopsys X-Mailer: Mozilla 4.51 [en] (WinNT; I) X-Accept-Language: en To: wind_talk@opus.hpl.hp.com-DeleteThis, david@windcall.com-DeleteThis Subject: Re: Why are the reports useless? References: <000401bed311$03e7cbe0$52e137ce@pokey.windcall.com-DeleteThis> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit
I think you touched on it at the end of your message but I wasn't 100%
percent sure what you guys were thinking of incorporating to the
website, so this is a request of what I want. I'd like to see exactly
how they are calibrated for all the wind directions and to have it on
the web. Maybe even a note as to where the sensor is. It would clue
people in to what's going on with the sensors far better. There is an
issue of trust now - we don't really know what's going on with the
sensors and we know calibrations are made and we're really sensitive to
anything that is happens to them.
Being told "it changed, it's more accurate now" is not something people
want to hear because all our experience with the sensor is suddenly
thrown out the window. For the directions 250-290 degrees it's adding
10% to the readings is more exact and something people can incorporate.
Being able to simply look at all calibration values at the web would
make it so we can check whenever we want to see if any changes were made
as well. That way, even if we miss an announcement we can still find
out whether or not it's changed instead of repeatedly going out to the
sailing site to see that it looks like it's a great time to go
waterskiing. Thanks.
Greg
"David St. John" wrote:
>
> Hi Sergei,
>
> Thanks for the comments. Sorry for the late response, but my wife and I
> (mostly my wife ;) were busy having a baby boy! A brand new little
> windsurfer-to-be. How soon can he start? Anyone know what the youngest
> kid's rig made is?
>
> I've followed most of this thread, I think. And I think I can answer some
> of your questions.
>
> > As callwind is concerned, it's more clear. The guys calibrate their
> > readers. I.e., what they show us is not what they get from sensors.
> > They make corrections trying to project what is on the water from
> > what they measure on shore.
>
> Yes, it's true that we *sometimes* calibrate the readings our sensors give
> us in an effort to give our members the most accurate data possible. Since
> we don't have sensors out on the water (yet!), we adjust the reading for
> certain directions when the anemometer does not have a clear view of the
> wind out on the water. Crissy field is the classic example - it can be
> glassy on the beach and a steady 25 knots at Anita Rock. So, we make
> adjustments to certain directions (about 20% to the SW reading) to give
> members the closest estimate of what the wind is doing. But sometimes the
> best the sensors can give you is just that: an estimate.
>
> However, for the vast majority of our sensors, you are seeing the actual
> reading - for most sites the wind on the shore is a pretty good gauge of the
> wind on the water. We make adjustments only after receiving lots and lots
> of feedback from from sailors at the particular site who have volunteered
> their input to help us make the system better. The adjustments usually
> happen in the first couple months of service - we rarely change them once
> the initial calibration is set. Since we know that people who sail
> particular sites regularly make their own mental calibrations (as you
> mentioned), we send out a message on the pager if ever a site's calibration
> is changed (again, that's very rare after the first few months a sensor is
> in service).
>
> The "field research" we've done confirms that the vast majority of our
> members would rather have the sensors calibrated than not.
>
> > Trouble is, their correction function
> > is apparently does not take into consideration the wind direction.
>
> Actually, as I mentioned above, our correction does take direction into
> consideration. We can adjust each of the 16 direction points individually
> from -50% to +50% actual reading.
>
> > I believe the callwind guys who carge for their service should consider
> > investing part of the proceeds into installing sensors on buoys, bridge
> > pillars, barges at 3rd, Anita rock, etc. Who needs wires in the midst of
> > Silicon Valley these days?
>
> We would love to have wireless wind sensors on the pillars, barges, buoys,
> everywhere! The technology, however, is not really the issue - it's getting
> the permission to put our sensors there. The vast majority of our revenue
> goes into the legwork necessary to acquire rights to, and install sensors
> at, new windsurfing sites; the rest goes into better technology and better
> information delivery mechanisms. No one is getting rich here, or even
> making a profit - we do this because we love it.
>
> > 1. Post TWO wind reports, with:
> > - raw data
> > - corrected data
>
> Posting two reports - raw and corrected - is a nice idea, but sure would be
> a pain to implement, and I think more confusing to most of our members.
>
> > 2. Announce any changes to the correction coefficients
>
> Finally, as I mentioned above, we *do* notify members when a change is made
> after the first "breaking-in" phase of a new sensor. And in the next
> iteration of our website we will have much more local information, including
> sensor notes and correction factors. So stay tuned!!
> --
> David St. John
> Call of the Wind
> http://www.windcall.com/
This archive was generated by hypermail 2b29 : Mon Dec 10 2001 - 02:35:51 PST