The Small Details of Largemouth Bass Fishing
(remember it’s happening in three dimensions, so it’s not a circle). Each satellite sits at the center of a sphere and you sit on the surface of a sphere, and (ultra-simply) where the surface of those four (or more) spheres meet, that’s where you are.
But here’s the funny thing. It’s all basically just one big set of sextant and chronometer problems with all the sights and math instantly taken care of for you. Instead of celestial bodies, it’s man-made satellites, but it’s still all about timing. Timing is everything, as was said once, perhaps by someone with bad timing. Bass fishermen on the tournament circuit can get very micro in their management of fishing data. That’s why they try to install a GPS antenna on their boat directly above anywhere there’s a transducer for a fishfinder. “A lot of fishermen place the transducer and the GPS basically in the same part of the boat,” says Lowrance’s Jeremiah Clark. “They know where they saw their target on the screen and that’s where they save their waypoint. We actually sell external antennas to consumers who will put them both on the front of the boat and on the back of the boat because they have sonars in both spots and transducers in both spots. Guys want that waypoint to be right on that structure. In our units we have the ability to choose our GPS source, so you can have several GPS sources on a boat to choose from. That’s how technical these guys have gotten.”
And it’s getting better all the time. “Since 2009, we’ve actually been through three generations of GPS receivers in that time, and each generation has become more and more sensitive and more and more accurate” says Jeremiah Clark, product manager at Lowrance ( www.low rance.com). “I think at some point you’re going to hit that PC processor thing when you start to max out on what benefits you get, but it has been a pretty steep curve on how fast GPS technology has advanced.”
As that powerful computer does a good job of incorporating all the data from the various systems, it also ferrets out the bad information and tosses it to keep the fix accurate. “If you run a measurement from a satellite that just doesn’t make sense when you compare it to other measurements available to you, you throw that measurement out,” Burgett says. “Many GPS receivers during the Glonass outage [in 2014] continued to work well because they threw out the Glonass satellite measurements and continued on the GPS measurements. Many people didn’t notice the Glonass outage because their GPS receiver had been designed in such a way that when the Glonass system started providing these erroneous measurements they were thrown out of the solution.” The outage lasted a reported 11 hours and was caused by bad data being uploaded to the Glonass satellites. The outage lasted as long as it did because new data had to be uploaded, and that had to wait until the satellites came back into view.
But the fact that we’re talking about an outage from two years ago is testament to the reliability of these systems. And you know what happens when something is reliable: People begin to rely on it. Another thing boaters want? Fast update rates. “When you’re using a trolling motor and you’re putting the boat in a cove and you maybe want to mark 50 waypoints in the cove, you want each waypoint to be right on the spot,” Clark says. “The big thing is update rate, measured in hertz. How many times per second the GPS information is updated. Our standalone, value products operate at 1 hertz. We get one position update per second, which sounds really good. Every