Running GPS vs. Course Length

RUNNING GPS VS COURSE LENGTH the reality behind the discrepancies Have you experienced that frustration of finishing a race, and having a reading on your personal GPS device that conflicts with the suggested length of the course? You may want to review prior to signing up whether the course for which you are registering is certified according to practices of a governing body such as the USA Track & Field association. All USATF certified courses are accurate within 1/10th of a percent. USATF COURSES ARE NOT MEASURED BY: SURVEYING EQUIPMENT MEASURING WHEEL CAR GPS TAPE MEASURE USATF COURSE MEASUREMENT PROCESS START A Jones measuring device is connected to a counter that attaches to a bicycle wheel The device is calibrated before A certified, experienced cyclist rides the bike the length of the course taking the shortest possible route the course is measured The cyclist rides the course until two readings are the same Taking diagonal routes when appropriate This means going straight through curves when possible The device is calibrated again afterwards Staying close to the curb HALF MARATHON CERTIFIED RACE DISTANCE 13.10938 MILES The Jones-Oerth is an 87 internationally accredited device for FUN FACTS: measuring courses The USATF manual for measurıng courses is 87 pages long BIGGEST LIMITATION IN GPS ACCURACY GPS satellites orbit the earth twice daily at approximately an altitude of 12,500 mi. above the ground. Consumer-grade GPS devices are accurate to 95% anywhere from 3 to 10 meters per reading 95% of the time The other 5% of the time your GPS could be off 10 or more meters per reading 1-20 GPS readings are recorded every 1 to 20 seconds sec THEREFORE... GPS devices are Curves in the road 1%) typically 1-3% off. In during the non-reporting intervals can be tracked a half marathon 1% is more than 1/10th of a mile! as a straight path GPS can record a longer distance by being off on its reporting locations DON'T THROW AWAY YOUR GPS! It is an extremely accurate estimate. As far as running tracking goes, GPS devices are great to get a very close approximation of the distance. FULL MARATHON CERTIFIED RACE DISTANCE 26.21876 MILES Rock'nRoll MARATHON SERIES® Races are USATF certified, so you can rest assured that the course is in fact the stated distance. FINISH BROUGHT TO YOU BY Rock'nRol MARATHON SERIES® www.runrocknroll.com © 2014 Competitor Group, Inc. All Rights Reserved