From rhoskins@home.com Tue May 2 05:58:11 2000 Received: from mxu2.u.washington.edu (mxu2.u.washington.edu [140.142.32.9]) by lists.u.washington.edu (8.9.3+UW99.09/8.9.3+UW99.09) with ESMTP id FAA10598 for ; Tue, 2 May 2000 05:57:47 -0700 Received: from mail.rdc1.wa.home.com (imail@ha1.rdc1.wa.home.com [24.0.2.66]) by mxu2.u.washington.edu (8.9.3+UW00.02/8.9.3+UW99.09) with ESMTP id FAA09398; Tue, 2 May 2000 05:57:15 -0700 Received: from c501552a ([24.5.121.123]) by mail.rdc1.wa.home.com (InterMail vM.4.01.02.00 201-229-116) with SMTP id <20000502125622.BJI2501.mail.rdc1.wa.home.com@c501552a>; Tue, 2 May 2000 05:56:22 -0700 Message-ID: <004601bfb435$d0244ed0$7b790518@olmpi1.wa.home.com> From: "Dick Hoskins" To: "Wright, Kevin" , "WILSON, BECKY" , "Waller, Patti" , Cc: "Sam Lamphier" , "Sonntag, Ron" , , Subject: Fw: Yesterday's Press Release [no more GPS error!!] Date: Tue, 2 May 2000 05:49:34 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6700 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6700 Dear Colleagues: Here are some "ground truth" observations about turning off the jittering on the GPS satellites last night at midnight. See below. Sam has the right spirit. Note the time. For those of you not yet quite geographically oriented in your public health work, this is a big big deal. For public health people: 1. The long and lat of a toxic site will be accurate when you do it with a $150 GPS unit. Any health department can have one now. "shoot" a suspect well, with a cheap unit, no need for expensive base stations. Environmental assessment can be done by anyone now. 2. It is now possible to use the GPS to "ground truth" GIS address geocoding. Cluster investigations can have a new level of accuracy never imagined yesterday. 3. Emergency response geocoding will put events on the correct side of the road, etc. 4. Our shellfish people can now map beds to foot accuracy rather than relying on old maps and "the XYZ bed extends from the boat launch near the Hoodsport Family Diner up to 20 feet this side Bill's boathouse." For hiking/Mt Climbing people: I guess I'll still carry an old fashioned compass, but I am now shopping for a GPS for sure to add to my pack. Topos suddenly are 100 times more useful than they were at 11:59. For environmentalists: Map suspected illegal clear-cut, birders can put the exact tree where Woodpeckerus redbackus was found, flower people can put a special grove of lupines on the map, tracking wild populations of wolves, caribou just became nearly cheap to do, might even be possible to put a GPS collar on teenagers. (venture capital anyone? a cell phone with a GPS unit that reports home to parents? (Jack at 12:01am now at -121.9206 47.05511 - that would mean he is in his room) Who out there has an application for the "new" GPS? Dick Hoskins rhoskins@home.com GIS uses in public health summer course: http://healthlinks.washington.edu/inpho/gis/course.html ----- Original Message ----- From: "Sam Lamphier" Sent: Tuesday, May 02, 2000 3:08 AM Subject: Re: Yesterday's Press Release [no more GPS error!!] > This appears to be the case -- no more Selective Availability error for > GPS. I tried out the GPS (within 4 hours of them turning off SA -- the > web is cool!) and had the following casual observations. > > - the claim was that we now have 10x more accurate positioning -- I > would agree that is roughly the case -- so now more like +/- 30 ft vs > +/- 300 ft before. > > - driving up and down the road (on different sides of the road) finally > puts you at the correct relative position, as you're often separated by > 15 ft or so. > > - likewise, intersections are nailed -- they're bigger than the 30ft > error (this means I can finally construct accurate custom maps) > > - going around our court finally makes a rough rectangle > > - benchmarks beside the road are usually on the correct side of the road > wrt the bread crumb trail > > - positions I spent hours integrating are very close as soon as you > reach them > > - this means GPS is now viable for walking (trails, trail heads, > locating items) whereas before it was really only good for driving and > gross location (like the size of a football field). > > - altitude on my unit used to be completely worthless... like +/- 500 > ft; now it appears to be about > +/- 100 ft; while driving you can actually see the elevation change on > low grades > > - I went out to the property and the driveway was finally in the correct > location wrt to the boundary markers I previously determined; and the > marks themselves were within 20ft or so vs 100s of ft before > > I think we'll finally see an explosion of GPS products, since we finally > have the accuracy to drive right up to someone's door (including > businesses). > > I had previously done 24hr integrations and had gotten roughly 10x > improvement -- I'm hoping this will be the case, so that I can get > something like 3ft accuracy -- that would be awesome, as I should be > able to see the difference between the two windows in the front of the > house. > > I wonder what a reasonable integration period is now -- with SA, I think > they had a mean of zero over roughly a 24hr (or maybe it was 48hr) > period. Now the error should be stuff like the position of the > satellites, whether there are signal reflections, and ionospheric > delays. > > Later, > Sam > > === > > http://www.whitehouse.gov/library/PressReleases.cgi?date=1&briefing=0 > > .