...Or Where Everyone Else Is Landing, But That’s Beside the Point
You’ve seen Star Trek, you big nerd -- so you know the answer to this question: When everybody’s staring out the front of a spaceship as it slams into warp speed, what are they looking at?
Don’t make that face. This absolutely applies to skydiving.
The answer, of course, is that they’re staring dramatically out into a starfield. Within that starfield, the outside stars are streaked into blurs and the center stars are distinct, clear and individual. At any given moment, the spaceship is headed towards the clear stars in the center of the frame.
Gene Roddenberry and his glitter-stirring co-wizards didn’t come up with that out of nowhere. they used a classic model, called the Radial Optic Flow Pattern (or ROFP), to base their screensaver-worthy visuals upon. Originally defined by scientist James J. Gibson, Radial Optic Flow has greatly driven the development of an “ecological” approach to visual perception. This approach investigates human vision in the context of the natural environment (as opposed to a laboratory).
It may sound obscure, but that same model is the one you, as a skydiver, should consciously use if you’d rather land in the peas than the trees. Here’s how.
Velocity Fields and FOEs
As a human in motion, your field of view – your very own spaceship windshield – is called your “velocity field.” Within that velocity field, when you’re traveling along a straight path (with no eye, head or body rotation), your heading is nailed quite precisely by the unmoving focus of expansion (FOE) in the center of your vision. How precisely? Well, a 2008 Oxford University study found that humans can use the FOE in optic flow to estimate their heading within one degree of the visual angle, and that’s good – because the FOE is exactly where you’re going.
As opposed to a paraglider – which can go up just as handily as down, in the right conditions* – a skydiving canopy has one essential mode: forward/down. A ROFP for forward movement describes expansion – like the stars in the front windshield of the spaceship as it rushes towards the FOE described by the still stars in the middle. (As our skydiving canopies can’t really go backwards, we won’t worry about the “reverse thrusters” mode.)
Where’s My FOE?
If you’re flying your skydiving canopy straight, your FOE is easy to pick off: it’s the place in your vision that isn’t dropping, rising, or side-sliding. As you approach the landing area, the FOE remains central while the rest of the field expands proportionally more quickly.
If you’re throwing a bunch of canopy inputs into the mix, however, it’s much more difficult to determine FOE. That’s because you’re introducing a “rotational component of lamellar flow,” which forces the retinal flow pattern not to be radial anymore, thereby making it difficult to recover the original heading.
How to “Energize” Your Accuracy:
When you set up your landing, choose objects on the ground and notice whether they’re moving up or down in your velocity field. Notice the still spot that indicates your FOE. Notice how accurate you can make your landings by fixing your FOE on your intended spot landing.
As you learn to determine your FOE close-up, start to work on spotting your FOE from higher and higher altitudes. By doing this, you’ll train yourself to know instantly if the spot is off and you’ll need to choose an alternate landing area.
Keep your FOE on the target, not an obstacle. When I was racing motorcycles, I used to refer to this trick as my “eye magnets.” That sounds just as silly as spending four hours in a makeup chair getting a rubber Klingon face glued on, but it’s not: your gaze truly is functionally magnetic. You'll head inexorably towards the one tree in the landing area you’re terrified of hitting (and thus staring at). Conversely, you'll kinda-magically turn away from that tree without any other conscious inputs if you “unstick” your gaze and attach it firmly to open turf. Improperly applied eye magnets are referred to less-cutely as “target fixation.”
Many skydivers refer to this phenomenon as “the accuracy trick,” which seems unfair – there are a lot of helpful tools for accuracy, of which this is only one. That said, consistently landing where you want to is a great way for a skydiver to live long and prosper.
(Shh. You know you giggled.)
** For this reason, “the accuracy trick” is a little trickier to use for paraglider pilots, because visual cues have a tendency to bounce around as the wing is affected by thermic “bubbles” near ground level.
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