measuring routes

[homer]

we organise cycleraces and would like to measure the routes profiles etc Could someone please assist and help with the model Garmin needed as well as any software to download etc.

                               Thanks

 

[Brakkies Sport Fotos]

huh, wat soek jy oom. homer simpson is 'n boffin met garmen, ek google earth vir jou. maar ek het ook garmin kaarte.

 

 

 

pick

[homer]

net n instrument om die roetes mee te meet. Iets wat nie te moeilik vir ongeletterde rekenaarpersone is nie. 

[slowjoe]

koop garmin 305 (edge of forerunner).

 

altimeter vir profile, gps vir afstand en routing.

[scotty]

Get an Edge 305 (HR and Cad) , beats the Polar 725 gli/gle/glx any day, create or copy routes, excercises etc  Sportsman warehouse has/had it on special R2999.00

[AndreZA]

net n instrument om die roetes mee te meet. Iets wat nie te moeilik vir ongeletterde rekenaarpersone is nie. 

 

what about one of these

 

http://img.alibaba.com/photo/11326629/Digital_Measuring_Wheel.jpg

 

[pbp2007]

If you just want to measure the route you could do it from your PC with appropriate software (Garmap SA Streetmaps is what I use). No profiles, though. For that you need to travel the route and record your track. The Garmin models mentioned above are fine - even my 301 is OK. But it might be more practical to have a proper recreational model ... try sending Mountain Lion a pm. He's da man.

[mountain_lion]

 

Most of the consumer type GPS models will do.

Garmin are by far the most popular. The latest modes with the "high sensitivity" receivers are great.

On the bike, the Edge 305 is a great training device.

The most appropriate model to get will depend on your budget and intended usage.

 

If you are just interested in plotting routes and profiles, you might not even need a GPS, especially if you are talking roads.

Most roads have been accurately mapped.

 

I have found that measuring ride distances from a map compare very well with actual recorded distances. Often much more accurate than the distances advertised by event organisers.

 

I have also been able to generate fairly accurate profiles of routes traced from maps sitting at my PC, using a DEM - digital elevation model.

I have posted some of these generated profiles on the Hub in the past.

 

Madmappers have DEM data of all of Africa at 90m resolution (the Americans have 30m but they do not make it freely available).

Various software can work with DEM e.g. Global mapper (but might be a bit expensive) or OziExplorer (basic but affordable).

Both of these are available in RSA from madmappers

http://madmappers.com

 

 

 

mountain_lion2007-10-18 13:44:35

[homer]

Thanks  mountain lion the sharing of your knowledge is appreciated

[Odion]

The other easy way to do it is via www.mapmyride.com which uses google maps. It gives you the ability to "draw" your route on google maps, recording the distance as well as the elevation.

[ShortLegs]

http://www.mapmyride.com/ride/south-africa/cape-town/1130115724

[BMCfan]

Durbanville High School Fun Ride (111.68 mi.)

Cape Town, South Africa

http://static.mapmyfitness.com/mapmyrun.com/images/icon_delicious.gif http://static.mapmyfitness.com/mapmyrun.com/images/icon_diggman.gif http://static.mapmyfitness.com/mapmyrun.com/images/icon_blinklist.gif http://static.mapmyfitness.com/mapmyrun.com/images/icon_furl.gif http://static.mapmyfitness.com/mapmyrun.com/images/icon_reddit.gif http://static.mapmyfitness.com/mapmyrun.com/images/icon_fark.gif http://static.mapmyfitness.com/mapmyrun.com/images/icon_yahoomyweb.gif

< ="http://www.geo.com/js/geo.js">

http://www.blinkgeo.com/templates/yget/images/buttons/blinkgeo_main_icon_16x16.gif http://static.mapmyfitness.com/mapmyrun.com/images/icon_add_to_blog.gif

 

does that mean 111Miles????

[ShortLegs]

Na, I mucked up the route, should be fixed now

Durbanville High School Fun Ride (89.13 km.)

[Jeeptrek]

I would use only Garmins (or Polar etc) with a barometer to create a profile. Normal GPS elevation measurements are not accurate enough. Garmin Edge 305 and Polar 72? do have a barometer, Garmin Forerunner, Quest etc don't have.

 

I can't comment on accuracy of software to calculate elevation.

 

 

[imagedee]

Homer,

I have a Garmin Etrex Venture I'm looking to sell.  It includes a bike mount and SA Map on CD.  I have PM'ed you with my details if you're interested.

[mountain_lion]

 

 

 

 

I would use only Garmins (or Polar etc) with a barometer to create a profile. Normal GPS elevation measurements are not accurate enough. Garmin Edge 305 and Polar 72? do have a barometer' date=' Garmin Forerunner, Quest etc don't have.

 

I can't comment on accuracy of software to calculate elevation.

 

[/quote']

 

Jeeptrek, you are correct that GPS elevation accuracy is not as good as GPS position accuracy. However GPS elevation can also be very accurate.

 

It all depends on the specific conditions.

If you have a good clear view of the sky from horizon to horizon and with a good satellite geometry  i.e. some satellites above as well as some nearer to the horizon, then GPS elevation is spot on.

 

If the topology (mountains, building etc) is such that a large portion of the the sky is obstructed, then you have to be weary of errors.

 

My main GPS use is mountaineering.

I have often seen elevation errors of 50m+ while ascending a mountain (half or more of the sky obscured by the mountain being climbed).

On reaching the summit beacon (good view of the sky), the GPS elevation error is often 5m or less when compared to the elevation given on the map for the trig beacon.

 

Barometer altimeters are weather dependent and need to be calibrated often. Weather can change rapidly (especially in the mountains) introducing large errors. You can only trust a barometer altimeter in stable weather.

The Polar devices which only use barometer can thus be just as bad as a GPS without barometer.

The GPS devices which also include a barometer use fancy algorithms to automaticly calibrate the barometer an correct the final elevation reading.

I have not used my Edge 305 long enough or in changeable weather to comment on the effectiveness of this function.

 

With all of that said, using GPS device without barometer elevation should be fine in most cases to profile a bike ride.

 

The accuracy of profiles generated by software depends very much on the DEM data used (and of course on the algorithm used by the software).

Most of the DEMs available for areas out side of the USA are based on 90m (or larger) grids, which is a bit coarse, but still usable and more than adequate to see where the major climbs are on a cycling route.

 

This is "recreational use" of consumer grade equipment after all, not accurate surveying. For that you need different tools.

 

mountain_lion2007-10-19 15:19:00