NOTE:
0) This calculator uses reported and forecast winds to determine an accurate
initial 'spot'. If your ground winds are different from what is reported locally, please enter what you see in the boxes. If the forecast winds are 'off', adjust your spot like we always have - they'll catch up !
1) The 'Land' icon is the
landing area, and the red line shows the
wind drift up to the 'Exit' icon, which is only the
mean (centre) exit point (or 'spot.')
2) The
range rings are at 1, 2 & 3Nm pointing at 30° intervals.
3) The
green range ring shows the area from which you can pretty safely get home [green light on and off ?!?], based on just about any rig being able to manage 1/2nm glide [nil winds] from 3000' - and much more on modern stuff, OH, plus allowing for pretty solid tracks away from the centre.
4) Everything drawn ON
THE SPOT-MAP is in ABOVE SEA LEVEL, as winds aloft are issued, while
CALC'S BELOW it are in ABOVE GROUND LEVEL, per our altimeters. Your DZ's position and elevation are accounted for here, so just enter your normal exit and opening altitudes as you see them on your altimeter - no number crunching necessary.
5) The
windsock point is where the ground winds are calculated to change over to the upper winds: there is no reliable way to estimate at what altitude this happens, this changes constantly in the normal atmosphere and is usually associated with some wind-shear turbulence if the change is at all rapid, so it's just set at half-way between ground elevation and the first wind aloft altitude.
6) The
parachute icon is the changeover point (thanks Jay for the typo check !) from free-fall drift to canopy drift, that is, you would drift to here from the exit point in freefall, and if you were under an open canopy at the altitude you entered above, you would drift (by doing nothing, like on a round canopy or a modern canopy with the brakes stowed, or one loitering in slow circles, &c...) to the 'LAND' point. Long story short, you should be able to get home easily from there.
7) Note that if winds are light (or 00) then some icons might not be visible as other (higher altitude) icons may be superimposed on them.
8) Zooming out (or using the 'Radar' buttons) shows you some
FD winds aloft location balloons, and how far they are from your dz if you hover over them, which are green if we're trying to use them for calculation, or beige if not.
911) Please don't steal or copy my work. There's no money involved in this. If you'd like your home DZ shown on the site and it's isn't yet, or I've identified the wrong landing area for your dz, or used the wrong winds or something, please and I really will update it as soon as I can. Cheers.
Safe jumps everyone.
(
Small print: Hi, this is a kaizen
(-for Gmap V2-)
in spot planning, it's now
2016.09.10 at 11:30
Toronto time.
No-one said this was perfect, indeed it's full of typos and mistakes, use only for fun and entirely at your own risk !)