Got Dead Reckoning?
New Passio Algorithm Boosts GPS Accuracy—AND Rider Satisfaction
Dead reckoning: The process of calculating current position of some moving object by using a previously determined position, or fix, and then incorporating estimates of speed, heading direction, and course over elapsed time.
A waiting rider checks the Passio GO app to see when their bus is coming. That arrival time is established by GPS, and the GPS reading, in turn, is determined by how long it takes the receiver to get data from satellites.
If that satellite signal is blocked by a concrete overpass in the way, or is reflected off buildings in an urban center, it’ll take the signal longer than expected to reach the GPS device. When that happens, the calculated location of the bus—and the projected arrival time—will be wrong.
What if too many of your routes are “off schedule” a little too often? Your riders’ comfort, confidence and satisfaction levels take a hit.
Enter Dead Reckoning from Passio—an easy add-on to GPS tracking. Dead Reckoning may sound like the title of a new western film, but it’s actually an exciting new algorithm that boosts the reliability of your vehicles’ locations in the Passio GO app, by correcting GPS data that’s inaccurate because of a weak satellite connection.
Plus, with built-in detour detection, Dead Reckoning lets you—and your riders—know if your bus is off-route.
How does Dead Reckoning work? Starting from the last known reliable GPS point, Dead Reckoning calculates a “cone of possibility” based on the speed and direction of the bus. The more recent that known “good” GPS point is, the more accurate the Dead Reckoning algorithm will be.
Dead Reckoning essentially applies an “accuracy check” to the GPS reading received from the device. Given that GPS essentially works on triangulation, the more points you have to triangulate, the more accurate the reading.
If you’re “talking to” eight or nine satellites, then your readings will definitely be more reliable. But if you’re only talking to three or four—and, perhaps, they’re too close together—you can’t expect the same level of accuracy. And that’s where Dead Reckoning comes in.
With Dead Reckoning in place, when your riders look on their Passio GO app to find out when their bus is coming, the arrival time that’s displayed will be far more accurate far more often. When that happens consistently enough, you dramatically improve the transit experience for your riders.
But the benefits of Dead Reckoning don’t end there. It also provides transit agencies with a host of new data that can help them analyze their on-time performance, improve ETA-adherence and help make better long-term decisions about their transit system.
Dead Reckoning is a simple add-on for GPS tracking. Once a transit system decides purchase it, Passio simply enables it on their server, and now all locations of that transit agency can enjoy the benefits. Says Passio CEO Mitch Skyer, “Dead Reckoning provides transit agencies with the next level of GPS accuracy, which, in turn raises rider satisfaction while delivering insight-generating data.”
