GPS for Dummies.pdf - Engineering Surveyor

Chapter 23: Ten Tips for Athletes345Aside from a GPS receiver and a cable to download the collected data to acomputer (see Chapter 9 to read how), you also need software so you cananalyze your performance based on the tracks that have been recorded.Some possibilities include Endless Pursuit (www.endlesspursuit.com): This Web-hosted, workout-loggingproduct is designed specifically for athletes. I review this inthe section, “Endless Pursuit.” TopoFusion (www.topofusion.com): Although this mapping programwasn’t designed primarily to log workouts, its authors include featuresso an athlete better understands his or her performance over a setcourse by analyzing track data, including moving, stopped, uphill, downhill,and flat time; up/down/flat distance; average uphill/downhill grade;and maximum speed. A recent beta version of the program included anathlete’s logbook and difficulty-and-effort indices for record tracks. Thisprogram, reasonably priced at $40, is turning into one of my favorite loggingtools. GPS utility programs: Two shareware programs — GPS Utility (www.gpsu.co.uk) and GARtrip (www.gartrip.de) — are general-purposeGPS tools but have features for analyzing track logs. Both programs havefeatures that examine distance, speed, and time data. Registered versionsare available for under $50. Spreadsheets: Because track data can be exported into comma- or tabdelimitedtext files (see Chapter 9 for a list of GPS conversion utilities,with some tips on using them), if you know your way around a spreadsheetprogram such as Microsoft Excel, it’s pretty easy to write yourown formulas and macros to analyze the data that you collect.GPS receiver limitations for trainingBefore you start training with a GPS receiver, don’t expect precise accuracyof the receiver all the time. Speed and distance measurements are based onexact position data; if the location coordinates the GPS receiver is reportingaren’t accurate, the speed and distance data isn’t accurate, either.The main cause of inaccurate GPS data is poor satellite signal reception. Whenyou train under heavy tree canopies, in canyons (whether natural or the urbantype from tall buildings), or anywhere satellite signals are obstructed, yourspeed and distance data isn’t going as accurate as if you had a clear sky.To me, this isn’t critical. The data from my GPS receiver is far more accuratethan guessing how far and how fast I’ve gone. I treat a GPS receiver as simplyanother tool that gives me training data to process so I can fine-tune myworkouts and performance, just like using a watch or a heart-rate monitor.