Cumberland ATV Riders

ATV's & UTV's & Proud Supporters of our Troops!
 
HomeCalendarSearchRegisterLog in
Latest topics
» Bledsoe State Forest Riding--Anyone Been?
Sun Jun 25, 2017 9:09 am by dkoogler

» Big Bottom Unit TWRA
Sat Jun 24, 2017 9:22 pm by dkoogler

» Mobile Two-Way Radio
Sun Feb 12, 2017 9:27 pm by ranger tim

» Any one ever ride Franklin State Park or Natural area TN
Fri Oct 28, 2016 12:14 pm by tosha20

» Tackett Creek?
Mon Sep 19, 2016 6:03 pm by bigcat

» Skyline WMA
Mon Aug 15, 2016 5:42 pm by pwm

» 2010 Polaris Ranger 800XP $8000.00 SOLD
Mon Feb 22, 2016 10:13 pm by ranger tim

» New Machine!
Tue Jan 19, 2016 10:29 pm by dkoogler

» New Place in NC Found!!
Tue Jan 19, 2016 3:20 pm by dkoogler

Similar topics
Search
 
 

Display results as :
 
Rechercher Advanced Search
Links
Mud-Throwers

Atv Trail Tunes

Four Wheelin Expeditions

QSC

October 2017
SunMonTueWedThuFriSat
1234567
891011121314
15161718192021
22232425262728
293031    
CalendarCalendar
Hit Counter
hit counters

Share | 
 

 GPS vs Odometer Distance Measurement

View previous topic View next topic Go down 
AuthorMessage
Dan
Senior Member
avatar

Joined : 2008-08-24
Posts : 754
Age : 74
Location : On a hill, Clinton, TN

PostSubject: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 10:03 am

Have you ever noticed that GPSr mileage is always ~10% less than your odometer readings? Well, there is a reason that happens. I'll try to explain it.

The GPSr measures distance along it's referenced coordinate system, a geodedic spheroid. This is basically an oblated sphere, a purely mathematically described surface, that should(?) represent the average earth surface. The GPSr coordinates are locations on this surface. Some GPSr units also rocord a calculated elevation that may be used in your computer programs, or used to display an altitude profile of your tracks. The GPSr calculated elevation is much less accurate than the location data and should be only used with caution.

The odometer measures topographical distance, or distance along the earth's actual surface, up and down hills and valleys.

So one good thing about this is that you cannot say your GPSr, or your odometer, is wrong just becuase they don't agree. They cannot agree, so don't expect them to. It take a sophisticated computer program to convert one type data to the other, using well defined topographical elevation data in the process.

A note of caution... a consumer grade GPSr should never be used for land surveys, or other measurement situations where precise locations are required. GPSr insturmentation is available to do this but costs run into several thousand dollars and is very cost prohibitive for us casual users.
Back to top Go down
pwm
Admin
avatar

Joined : 2008-01-15
Posts : 10937
Age : 53
Location : Knoxville, TN

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 5:56 pm

Alright, where did you copy this from Very Happy

_________________
2010 Ranger XP 800
PP Windshield F&B, EMP EXT Bumper, Warn 40XT, Kobalt Box, Backwoods Armor 2" Lift/Arched Forward A-Arms, ProArmor Doors, DJ Fab Heat Shield, KFI Front Hitch, UTV Tech Mud Guard & Grill Insert, Crow 4-point Harness, Hi Lift Jack, 27" Horns, SS108's, Garmin 76csx, IPOD 80GB w/Otter Box, ATV Trail Tunes Sounds, Dual Battery Setup,  2-way Radio, PWM Built Spare Tire/Gas Carrier, Diamond Back Top & Floor Mats, HID's, FlexSteel Seats


PWM's Pix

Back to top Go down
Dan
Senior Member
avatar

Joined : 2008-08-24
Posts : 754
Age : 74
Location : On a hill, Clinton, TN

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 6:17 pm

Phil, why would I need to copy anything? Has someone already posted info about this? If so, I would like to apologize to them. Some of the GPS sites go into great detail about this, and I thought folks would be interested.
Back to top Go down
pwm
Admin
avatar

Joined : 2008-01-15
Posts : 10937
Age : 53
Location : Knoxville, TN

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 6:24 pm

Dan wrote:
Phil, why would I need to copy anything? Has someone already posted info about this? If so, I would like to apologize to them. Some of the GPS sites go into great detail about this, and I thought folks would be interested.
Opps I thought it was Outlander Dan that posted this so I was ragging on him. Embarassed Very Happy Sorry I need some rest

_________________
2010 Ranger XP 800
PP Windshield F&B, EMP EXT Bumper, Warn 40XT, Kobalt Box, Backwoods Armor 2" Lift/Arched Forward A-Arms, ProArmor Doors, DJ Fab Heat Shield, KFI Front Hitch, UTV Tech Mud Guard & Grill Insert, Crow 4-point Harness, Hi Lift Jack, 27" Horns, SS108's, Garmin 76csx, IPOD 80GB w/Otter Box, ATV Trail Tunes Sounds, Dual Battery Setup,  2-way Radio, PWM Built Spare Tire/Gas Carrier, Diamond Back Top & Floor Mats, HID's, FlexSteel Seats


PWM's Pix

Back to top Go down
Rooster
CATVR Junkie
avatar

Joined : 2008-03-21
Posts : 4380

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 6:29 pm

Thank you Dan. I figured there was a good explanation for that difference. Now we know why.
Back to top Go down
pwm
Admin
avatar

Joined : 2008-01-15
Posts : 10937
Age : 53
Location : Knoxville, TN

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 6:30 pm

Rooster wrote:
Way to go Phil..... bonk
I try Very Happy

_________________
2010 Ranger XP 800
PP Windshield F&B, EMP EXT Bumper, Warn 40XT, Kobalt Box, Backwoods Armor 2" Lift/Arched Forward A-Arms, ProArmor Doors, DJ Fab Heat Shield, KFI Front Hitch, UTV Tech Mud Guard & Grill Insert, Crow 4-point Harness, Hi Lift Jack, 27" Horns, SS108's, Garmin 76csx, IPOD 80GB w/Otter Box, ATV Trail Tunes Sounds, Dual Battery Setup,  2-way Radio, PWM Built Spare Tire/Gas Carrier, Diamond Back Top & Floor Mats, HID's, FlexSteel Seats


PWM's Pix

Back to top Go down
REPOMAN
Moderator
avatar

Joined : 2008-02-01
Posts : 4111
Age : 49
Location : CROSSVILLE,TN

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 6:51 pm

roll PWM and thanks for the info Dan
Back to top Go down
THE ROXSTAR D
V.I.P Member
avatar

Joined : 2008-01-23
Posts : 1287
Age : 37
Location : Sevierville,Tennessee

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 7:21 pm

That makes since. We were riding at royal blue one day and we went about 4 miles but the gps said only 1.5 and I was just wondering why. Thanks, now I know
Back to top Go down
ollie
CATVR Junkie
avatar

Joined : 2008-06-27
Posts : 3532
Age : 48
Location : attalla,AL.

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 7:27 pm

tire spin is why!
Back to top Go down
Dan
Senior Member
avatar

Joined : 2008-08-24
Posts : 754
Age : 74
Location : On a hill, Clinton, TN

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 7:51 pm

ollie wrote:
tire spin is why!
That is an add on error...

Some of us don't sit around and spin in one place... Shocked roll
Back to top Go down
g-man
V.I.P Member
avatar

Joined : 2008-06-09
Posts : 1339
Age : 47
Location : Columbia, TN

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 10:50 pm

Looks good Dan...FYI, you can usually get some good quality GPS surveying equipment for less than $100k......at least I hope it is not that expensive, we have 2 at work :-)
Back to top Go down
Dan
Senior Member
avatar

Joined : 2008-08-24
Posts : 754
Age : 74
Location : On a hill, Clinton, TN

PostSubject: Re: GPS vs Odometer Distance Measurement   Mon Mar 09, 2009 11:46 pm

Trimble makes a small handheld that will do sub-centimeter precision/accuracy for about $3K. But then the software to support it is several more grand.
Back to top Go down
Sponsored content




PostSubject: Re: GPS vs Odometer Distance Measurement   

Back to top Go down
 
GPS vs Odometer Distance Measurement
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» does changing the rear drive change the odometer signal?
» Ventura Rack measurement
» Odometer failure
» Actual measurement of a reebok sz52?
» Toe in measurement

Permissions in this forum:You cannot reply to topics in this forum
Cumberland ATV Riders :: General :: GPS Talk and Information-
Jump to:  
Private forum on Forumotion | Sports and Hobbies | Quad | © phpBB | Free forum support | Report an abuse | Free forum