2018 Alligator Trot 5k
USATF
The 5k Alligator Trot is now USATF Certified!!!!
Lake Jackson Course - Certification # AL 12040 JD
WHY DOES THE COURSE MEASURER SAY THIS IS 5K WHEN MY GPS SAYS…?
Course Measurer | Topic | Runner with GPS |
USATF and IAAF: “…a course not shorter than the advertised distance.” |
Define “Accurate Course” | Varies from person to person |
3.1068560 miles exactly
|
Define 5K | Most say “3.1 miles” |
At least two | Number of unhindered trips on course | Depends on experience & course knowledge |
Mechanical (Jones-Oerth or Jones-Riegel) |
Measurement device | Electronic (Consumer- grade GPS) |
Counts (23 1/3) per revolution of bicycle wheel |
Means of measurement | Triangulated time to receive radio signal from one-to-four satellites |
±3 inches continuously
|
Degree of accuracy | 3m-10m radius 95% of time; 11m->30m radius 5% of the time |
Calibration must be done at least twice each measurement day |
Device ensured accurate? | Accuracy can be displayed but not controlled |
Measurements must not vary by more than .08 percent (13 feet) |
Comparison between trips? | Possible, but not before race day |
Shortest possible distance a runner can legally take on course |
Course travel | Depends on experience & placing in race |
Exact start & finish points on course |
Start and end of measurement? | Most start with gun/horn, not at start line |
20-year road racer, 8-year measurer, 24 active certified courses (440yd to marathon) |
Experience level? |
? |
All work approved by certifier/measurer of over 50 active courses |
Oversight |
? |
Consumer-grade GPS units are a great training tool, but: “... the phenomenon of GPS technology has added some unique, valuable, and fun aspects to running, don't be fooled into thinking the course is not accurate just because your GPS indicated something different — these devices are not always right…” (Dave McGillivray, Race Director, Boston Marathon)