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Exo
07-14-2011, 06:10 PM
For some reason it just hit me... I don't know exactly how GPS works but, I believe it shows speed, location and, altitude...(correct me if I'm wrong). Has anyone ever used their hand held GPS while on a Disney coaster to record these? It would be neat to see when and where and how fast while on the ride.

PETE FROM NYC
07-14-2011, 06:48 PM
I don't think a GPS can update that fast.

DizneyRox
07-14-2011, 07:22 PM
Never tried it, most probably don't update fast enough to give you a terribly accurate representation of the ride. There may be some phone based that apps that may be useful, but at Disney with rides being indoors etc, they wouldn't work well without LOS.

azcavalier
07-15-2011, 09:21 AM
It might update the speed, but I doubt it would do the rest that fast....I mean, it can keep up with my car doing 70mph, right? But none of the coasters are that fast. The changing direction would probably be hard to keep up with, though.

ibelieveindisneymagic
07-15-2011, 09:29 AM
I'm having flashbacks to my grade 12 physics project! We had to analyze all of the forces on a ride, how much G-force, the speed, etc.

It was actually really neat (although annoying to measure everything, riding the ride OVER AND OVER AND OVER AND OVER again).

It would be neat if something like GPS could it is all for you!

Dulcee
07-15-2011, 10:17 AM
I'm having flashbacks to my grade 12 physics project! We had to analyze all of the forces on a ride, how much G-force, the speed, etc.

It was actually really neat (although annoying to measure everything, riding the ride OVER AND OVER AND OVER AND OVER again).

It would be neat if something like GPS could it is all for you!

We did this too! Only in the advance placement class we had to design the questions for the regular physics class. Pretty cool in retrospect.

wdwfansince75
07-15-2011, 10:57 AM
GPS is a positioning system...it measures location in terms of distance from from 3 satellites...and measures location again and again...but not continuously...It does not know your heading (direction of travel-most auto GPS's have maps installed, so they do know the road direction at any given location...hopefully, the vehicle heading and the road direction are the same)... A GPS determines speed because it knows your path (internal map) and the distance between to GPS locations..and knows which one you passed first...speed is distance traveled devided by time...
With today's data storage capabilities, a GPS device could determine sufficient numbers of locations, and store them, so with the appropriate calculations, you could process and display a complete "flight path"...Just as most aircraft navigation systems today do for pilots...and just as autopilots fly aircraft to their destinations, the technology is there to keep the vehicle on the road at all times...as long as there are no other vehicles in the way. One of the continuing law of physics...two solid objects cannot occupy the same space at the same time.

Not totally simple, but well within the state of the art..and if the device were developed with the actual track plan in the system (just as today's automobile GPS devices have maps), it could give you exact heading, altitude, speed...and even g's...

ryca1dreams
07-15-2011, 12:18 PM
A handheld GPS does not rely on a "track" (ie: a map) but shows direction of travel, speed, etc. by lat/long coordinates. In theory you could track a ride if you had one that could measure this on a small enough scale - maybe a 12 digit MGRS/UTM, but as others have said, I'm not sure it would update fast enough for something like Space Mountain.

Altitude in these units, if it has it, is generally measure by barometric pressure (assuming your starting point is correct) or relative position on a built in topographic map which, again, is hard to measure that fast. Most coasters don't show their topography on a map! :mickey:

Ed
07-15-2011, 12:54 PM
A little :offtopic: but I like to take my GPS on aircraft with me and stick it to a window. Mine does not show altitude, but it stores stuff like maximum speed, etc. and gives me an idea of where we are and what our ETA is.

It kinda spooks people when I recall the speed display while the unit is in my truck and they see that I've apparently had my truck up to 550 MPH. :D

:truck:

wdwfansince75
07-15-2011, 03:18 PM
Altitude in these units, if it has it, is generally measure by barometric pressure (assuming your starting point is correct) or relative position on a built in topographic map which, again, is hard to measure that fast. Most coasters don't show their topography on a map! :mickey:

OK, I'm going out on a limb here...GPS locations are basically x, y, and z coordinates...fix relative to 3 balls in space...solves as lat/long for surface (auto, boats, and people) but also solves altitude, relative to sea level....one of the original selling points for GPS was that it did away with need for Barometric and Radar Altimeters...although they were initially kept as backups. Hard to convince seat of the pants pilots that they could fly nap of the earth in total Instrument Flight Rules (IFR) environment...

Polynesian Dweller
07-15-2011, 05:12 PM
You were out on a limb. GPS receivers use at least 4 satellites in order to give position AND altitude. They actually calculate their distance from the satellites and the intersection of the spheres is where you are located. The spheres actually intersect twice, 180 degrees apart. But only one can be on the earth so that's the one used. The distance of the intersection from the satellite signals used is translated into position on the earth's surface.

Ok that's really simplified a bit and how it works is really quite complicated, too much so for a post here. But for the OP, the real problem is that handheld GPS receivers only update about every second because of the complexity of the calculations. You'd get a rough outline of the coaster but lots of the detail of turns etc would be missed.

ransam
07-18-2011, 01:43 PM
i can hardly hold on to my senses, much less a GPS on a roller coaster!

Mufasa
07-19-2011, 05:04 PM
In theory, you could get reasonable results if you were to use a newer iPhone/iPod Touch by taking advantage of the built in accelerometers and either the gyroscope/magnetometer also.

And if you had an external fixed reference for location then your results could be very good.

Accelerometer data by itself would indicate G forces which is interesting to look at (and experiments that are a favorite of high school physics classes) but you really wouldn't be able to construct a track map from that data alone.

If you had information from a gyroscope to correct for the device's rotational position then you can get some reasonable results from dead reckoning as you could derive reasonable position information (you could cancel centrifugal forces from true linear acceleration).

smsp
07-22-2011, 05:38 PM
I'll be in WDW in Novemeber 2011. I am planning on bringing my Garmin 60csx just to have in my backpack to track how much we will be walking throughout the day. May have to try it on a ride and see what happens as well.

SMSP