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[DPRG] Long Haul Way Points

Subject: [DPRG] Long Haul Way Points
From: David P. Anderson dpa at io.isem.smu.edu
Date: Sun Sep 10 14:38:48 CDT 2006

Howdy,

Martin, the finish waypoint on the webpage I think is perhaps
a typo.  The coordinates are listed as

finish		32.77791 N	96.7646 W

Seems like the longitude is truncated?  That puts the point out
in the parking lot, as John observed.

Should that perhaps be:

finish		32.77791 N	96.76246 W

??

best
dpa


> 
> All:
> 
> The differences in GPS coordinates don’t come as any
> surprise to me. That’s why I also described the course
> in terms of headings, distance, and pictures. After
> yesterday’s meeting two potential competitors walked
> the course with their GPS’s, and noted discrepancies
> between their readings. If they’d like to share their
> results, I’d be interested in comparing them to what
> I’ve already calculated. The maximum difference
> between what yours and my readings are about 2/1000.
> That doesn’t sound like much; until you realize how
> much distance a single degree covers.
> 
> What does surprise me is not being able to get a lock
> at some key way points. When mapping the course, I
> made sure I could get at least 5 satellite’s per mark.
> But I wanted this to be a contest of ingenuity, rather
> than who has the best equipment. In that spirit, Eric
> offered an interesting suggestion yesterday, when
> another GPS had the results you mentioned: Activate
> your robot far enough away from the building to get a
> satellite lock prior to the start of the attempt. Then
> direct the robot to the starting area, and use
> odometry to compensate. There is nothing in the rules
> about taking that approach.
> 
> > For those who might like to try another challenge
> while we are at FiarPark,
> > here are the 2 waypoints to go from the meadow next
> to the Science Place
> > to the meadow next to Texas Star Ferris wheel, which
> must circumnavigate the
> > Band Shell, as jBot demonstrated in a round trip a
> few months ago:
> 
> I have no problem with this, provided it does not
> disrupt the planned contest or distract from the
> people running attempting to compete.
> 
> -Martin
> 
> 
> --- "David P. Anderson" <dpa at io.isem.smu.edu> wrote:
> 
> > Howdy,
> > 
> > I went by Fair Park yesterday to verify Martin's
> > waypoints and got the
> > following.  John, you might try these out with
> > Google Earth:
> > 
> > start:	N  32.77715
> > 	W 096.76190
> > 
> > waypt1	N  32.77753
> > 	W 096.76208
> > 
> > waypt2	N  32.77770
> > 	W 096.76266
> > 
> > waypt3	N  32.77790
> > 	W 096.76249
> > 
> > Note that these are specified in decimal degrees
> > (hddd.ddddd) as are Martin's
> > rather than degrees-minutes-seconds.
> > 
> > The first waypoint is in the shadow of the Science
> > Place building on two sides
> > and I was only able to get three satellites at that
> > location, so it is not
> > a very accurate measurement.  Likewise with waypt2,
> > which is in the building
> > shadow and also under a large tree.  
> > 
> > For those who might like to try another challenge
> > while we are at FiarPark,
> > here are the 2 waypoints to go from the meadow next
> > to the Science Place
> > to the meadow next to Texas Star Ferris wheel, which
> > must circumnavigate the
> > Band Shell, as jBot demonstrated in a round trip a
> > few months ago:
> > 
> > start:	N   32.77634		// Water cover next to TSP
> > 	W  096.76179
> > 
> > end:	N   32.77631		// In front of Ferris Wheel.
> > 	W  096.75965
> > 
> > 
> > A little more challenging is the route from the
> > Science Place meadow, 
> > across the entrances and parkinglots to the field
> > behind the Natural
> > History Museum:
> > 
> > start:	N  32.77636		// Water cover next to TSP
> > 	W 096.76179
> > 
> > end:	N  32.77821		// Behind Nat'l Hist Museum
> > 	W 096.76369
> > 
> > 
> > For those without obstacle avoidance working, you
> > might want to at least
> > run a demo course.  Here is one laid out earlier
> > this year. This was for
> > those who might have a navigating robot but don't
> > have obstacle avoidance
> > working yet.  
> > 
> > It begins in front of the Cotton Bowl and has a
> > second
> > waypoint at a bend in the road, and a third point in
> > front of the Aquarium where the path is blocked.
> > 
> > Plaza in front of Cotton Bowl (intersection of brick
> > paths):
> > 
> > start:	N  32.77790 		// Cotton Bowl Plaza
> > 	W 096.76112 
> > 
> > 
> > waypt1	N  32.77707 		// Corner of Band Shell:
> > 	W 096.76085 
> > 
> > 
> > finish:	N  32.77654		// In front of Aquarium
> > 	W 096.76042 
> > 
> > Here is an ariel view with the route marked out in
> > red, from
> > upper left to lower right:
> > 
> >
> <http://geology.heroy.smu.edu/~dpa-www/robo/jbot/jbot2/fairpark2_x.jpg>
> > 
> > 
> > best,
> > dpa
> > 
> > 
> > John wrote:
> > > I plotted the way points with Google Earth.  I
> > don't know what is ground
> > > truth, that is Google Earth also has errors.  I
> > was comparing them to
> > > the map posted on the web.  
> > > 
> > > Start:  Was in the grass NNE of the round doom.
> > > WP1:  Looked like it is on the edge of the
> > sidewalk.
> > > WP2:  Halfway between building and sidewalk, 8
> > meters from the corner of
> > > the building (to the southeast)
> > > Finish:  Across 2d street in the parking lot 195
> > meters from WP2.  This
> > > point was also located here by TopoUSA.  Since
> > TopoUSA doesn't show the
> > > building (all of Fair Park is just a green blob) I
> > couldn't use it to
> > > verify the other points. 
> > _______________________________________________
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> > http://list.dprg.org/mailman/listinfo/dprglist
> > 
> 
> 
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