Spotting calculator

[kallend 1,623]

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Why is it so tough to get you to understand that all I was looking for was a simple spot calculator?

Simple != Spot Calculator.
If you want simple - go on Green and takes your chances.

?

I think it's pretty simple, and I do the math in my head.

...

The only sure way to survive a canopy collision is not to have one.

[hackish 8]

I know I'm at a small DZ, but none of the 2000-3000 jump old guys who have been doing it for 30 years ever used a calculator. They do as I was taught, look at the uppers and have a discussion about where the spot should be.

When I look at some of the stuff recent business graduates are doing to figure out costing I get dizzy. I look at a gizmo and say I've got to sell it for $500. They go and churn numbers for an afternoon and come back to say "you need to sell it for between $486.33 and $515.92"

Maybe our weather makes it easy? Is it really a problem? Is this exercise looking for a solution without a problem?

In business and spotting you hone the skill with a series of near-misses, hits and major fuckups. Not many walks back to the LZ last year at my DZ.

-Michael

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It's like a business student running fomulas versus an old businessman who just knows from experience what to sell a product for.

But, let's not forget, the older experienced businessman once had to do the formulas on paper, before his experience allowed him to do them in his head.

Several former Jumpmasters and Pathfinders in this thread... we started out doing the the formulas on paper long before we had the experience or confidence to do them in our head.

[JohnRich 4]

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Winds aloft "forecasts" are now more like winds aloft reports, with wind info being downloaded in real time from hundreds of a/c in flight. Even so, I'd never bet my life on the reports.

I'm amazed at all the complexity that people keep building into this problem.

And then I keep going back to the old-fashioned wind drift indicators.

Just think of the advantages of that piece of crepe paper. It doesn't depend upon general forecasts - it demonstrates actual wind conditions, right now, at your exact location. And then all you have to do is draw a straight line from the WDI through the landing area, equidistant out the other side - and there's your spot. That's the way it was done in the old days, on an aerial photo with a grease pencil. It didn't require a computer, winds aloft reports from gosh knows where, k-factors, or anything else. Just crepe paper and a pencil!

If spotting is that big a problem for people these days, then it's time to go back to old-school.

[BIGUN 1,053]

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If spotting is that big a problem for people these days, then it's time to go back to old-school.

I'm in agreement... let's start with round canopies... that'll make people do more than go on green.

Nobody has time to listen; because they're desperately chasing the need of being heard.

[Liemberg 0]

You mean something like some clever dutchman from Rotterdam wrote for Skydive Rotterdam but that also works for al the Dutch DZ's, a website / gizmo that fully automatically takes the general aviation forecast into the equasion and works with google earth images?


Yeah, smart idea...




OTOH we could start dropping widi's again...

In the left upper corner of "mijndropzone.nl" you find a pull down menu called "WEERGAVE". If you click on it you see all the places in Holland where there is a DZ. Everyone can select his own DZ and see where the spot is and what a left hand circuit ought to be.... These kids with their computers... djeessszsss...

"Whoever in discussion adduces authority uses not intellect but memory." - Leonardo da Vinci
A thousand words...

[SethInMI 145]

Nice work by the dutchman. My web skills are 0, so I am stuck with an "offline" solution.

Nevertheless, I updated the free fall simulator I wrote to calculate the spot. By adjusting the canopy descent rate you can adjust the spot. The default descent rate is 6mph like a canopy w/toggles stowed.

If multiple groups are out the spot will be adjusted so that touchdown points of the farthest groups will be equidistant from the landing zone.


Free Fall Simulator for Google Earth

It's flare not flair, brakes not breaks, bridle not bridal, "could NOT care less" not "could care less".

[adrenalin 0]

Coming soon to a browser near you... Spotting (HARP) Calculator

http://208.112.78.179/harp_page.cfm

Here is a peek at my soon to be released web based tool for skydivers & aviators alike. Just click where you want to land and set your altitudes and that's it. I use the same method as the good ole' Army manual without the averaging or 'Dog Legs'. The map will automatically get the winds aloft data for your LZ and does all the math for you. It even provides the jump-run initial, release, & departure coordinates for Mr. Garmin. I can even draw special zones and lines to highlight any obstacles in your area that jumpers & pilots might not be aware of.

Please let me know what you think and if you have any suggestions.

TTFN - DJ

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)

[adrenalin 0]

I've changed the location so just go to...

http://www.digiacom.com/HARP/harp_page.cfm

Please take a look and let me know what you think

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)

[GreenLight 5]

Best way to learn to spot is to jump a round for a while.

Green Light
"Harry, why did you land all the way out there? Nobody else landed out there."
"Your statement answered your question."

[bofh 0]

I don't get your spotting calculator.
The Freefall setting: "The base amount of horizontal drift experienced by jumpers" - what's that? The drift depends on the wind and the freefall speed, no?
If I change the Heading to something else, how do I get a new spot? Pressing the "redraw from saved..." link at the bottom only resets the values.



But since this old thread was talking about spotting calculators and their value...

I jump at a dropzone with a single PAC750. It is not rare to have eight groups in one jump run and therefor the jump run can be quite long. We don't normally allow two jump runs.

We used to have the most experienced people predict the spot, then the same people sat in the door and spotted. It was also not rare that the first group got back with plenty of altitude and the last group/person would have to pull higher or land out.

Then our S&TO made a spotting calculator, its called SpotIt and is a program for windows. The result from it is a printed map with the jump run as an arrow on the map with the first and last point of the jump run, instructions to the pilot, the time between groups, the wind speeds and directions. There are also two large circles showing where one can jump out and where one is expected to be hanging in canopy. An example can be seen here:
http://fkcg.2me.se/public/attach?page=ForklaringSpotITKarta/SpotkartaHelp.jpg

We changed our operations to turn on the yellow light 30 seconds before the green light (yellow also means that the pilot is making his final turn and should shortly have the right heading) and the green light was turned on 10 seconds before one was supposed to jump to give the first group time to line up after visually verifying the spot. After these changes our spots have improved a lot. Its rare for the last group to have to pull higher and there are fewer people landing out. But it took a while to get some of the old, experienced people to accept this...

The input to our program is the winds (can be downloaded with the push of a button), the kind of airplane (thus getting the speed, default forward throw and exit and deployment height), the dropzone (to get the right map). One can also change how fast people are falling in freefall, how fast they descend under canopy. One can change the jump run to specific headings (and the program will complain if that becomes a bad spot) and if the jump run must pass over the landing place or not (it usually does since most of the pilots don't like/know how to move the coordinates in the GPS).

[DougH 270]

Does you dz want to shae the program?

"The restraining order says you're only allowed to touch me in freefall"
=P

[adrenalin 0]

I'm looking for people to test & comment on my spotting calculator. If you would like to participate, then please send an e-mail to me and I'll give you a login. Your login allow you full control over YOUR spot details that will be saved to your account.

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)

[adrenalin 0]

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The Freefall setting: "The base amount of horizontal drift experienced by jumpers" - what's that?

This is the amount of drift, or how much the winds at altitude will push you sideways (horizontal) for every 1,000 feet you fall (vertical). Because the winds are different along the way (speed and heading) you are being pushed sideways at varying speeds and directions during your entire fall. The same is true while under canopy (the program assumes you make no attempts to steer your canopy and you simply drift along with the wind until you land).

My program calculates these pushing effects, or vectors, for every 200 feet of vertical distance traveled giving you a more accurate spot than just averaging the speeds & headings and then drawing a single vector line from the landing zone (LZ). Also, the drift values are adjustable so you can calculate different spots for head down small canopy jumps (fast movers effected less by drift) vs. belly flying student/tandem jumps with bog canopies (slow movers effected more).

As for larger aircraft with multiple exit groups I have a 'Jumprun - Cross Wind' setting. The calculates the GPS coordinates the pilots need to fly the line crosswind. Cross wind jumpruns provide the largest exit window for the exit grouping you describe. This helps the pilot get everybody out in a single path with the best chance of getting back to the LZ safely.

P.S. Please forgive my 'Student/Wuffo' level explanation ... I want to make sure that all readers will be able to follow and understand more about the details of spotting.

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)

[bofh 0]

Yes, I understood that later when I read the other linked powerpoint.

Would it not be easier for the users to understand if they enter the freefall and canopy vertical speeds instead? Those are easy to know, measure and understand. I assume the drift value is some constant * altitude/vertical speed.

[bofh 0]

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Does you dz want to shae the program?

Its made for swedish dropzones, it downloads the forecasts from some swedish site that only covers Sweden. It assumes the winds are measured at specific altitudes (which might be the same in all countries), the altitude settings are in meter.

I guess that wouldn't be a problem, but the programmer lost the sources to it in a harddisk crash too. But you can always ask him, PM me if you want his email.

[adrenalin 0]

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Would it not be easier for the users to understand if they enter the freefall and canopy vertical speeds instead?

The vertical speed/distance isn't the problem. That is to say if there were no forward throw from the aircraft, no winds, no drift, and no horizontal movement during your descent you would land directly below where you exited. Your rates of descent or vertical speeds would only help tell you how long it's going to take for you to touch down not where you most probably will touch down.

The various spotting applications out there are just doing all these mindless drift calculation chores for you. As for my web site, it automatically gets the closest winds aloft information for you as well (US only for now) thus eliminating more several painful steps in the process. For extra flavor, I added in the US NAVAIDs and Obstructions (towers, etc.) for the pilots who have to bus us around. This information comes in real handy when jumping a DEMO into an unknown location.

Again, these programs are simply suggesting that if you want to land 'Here' you hsould get out 'There'.

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)

[popsjumper 2]

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I've changed the location so just go to...

http://www.digiacom.com/HARP/harp_page.cfm

Please take a look and let me know what you think

I think it's not working.
I think it's not user friendly.
I think I'd use something else.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[adrenalin 0]

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I think it's not working.
I think it's not user friendly.
I think I'd use something else.

Just checked and the link provided is working fine. If however you still can't get there try going directly to ... http://www.digiacom.com ... the 'Spotting' links are on the left-hand side menu.

If all else fails try getting with one of the younger tech-savvy jumpers at your DZ; they should be able to help you with using your computer and Google Maps. I know it can be confusing as I have to help my parents out all the time with using their computers and they are only in their 80's.

By the way ... 99 years in the sport is impressive! Are you still jumping? I bet you have some stories to tell. But really, thanks for your detailed commentary. It's obvious you took some time to go over my submission in detail. NOT!

I guess for some it's easier just to 'Quick-Slam' something than to actually take the time to explain why and/or make some 'constructive' recommendations as to how it could be made better. Or perhaps you are just bored and want to stir things up in this blog (I'll put my money on the later based on the 7+ posts you make every day). You've made it clear from your DZ.com identity that you want other users to know who you are, what you are, and what you stand for.

And yes I agree that we are all Bozos on this bus ... I just want to know who's driving!?

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)

[popsjumper 2]

Panties in a wad or what?
You asked, "What do you think."

We're talking about your program are we not? How did you get off-track on the links?

The page link works.
The link in the sidebar works.

Doing anything to the actual numbers on the other side doesn't seem to do much of anything as far as I can tell. It's already been mentioned to you in a previous post by others.

Since your "instructions" in your post don't work and there's no "how to use this convoluted stuff" on the page that I could find....it's no good.

I'm sure that if one wanted to work at it, and become a software engineer, he'd figure it out sooner or later....if it works at all. Hence the user-friendly comment.

YOUR friendliness makes me want to try even harder to figure it all out....well, not really.

And yes, if I were to need something like this, I'd use something better until you improved your version for usability.

BTW...congrats on noticing and focusing the profile info. Baited and reeled another one in. You've earned a special place on my trophy wall.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[kallend 1,623]

Spotting isn't exactly rocket science. I bet anyone of my generation can do the math in their head.

But then, we can also make change without needing a calculator.

...

The only sure way to survive a canopy collision is not to have one.

[popsjumper 2]

Yes...emphatically.

While I am of your generation, I'm slightly behind you in experience but even I can do it. That tells me that nearly anyone can do it...if they took the time and trouble to learn.

I still love Happythoughts "cup of coffee" method, though.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[adrenalin 0]

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BTW...congrats on noticing and focusing the profile info. Baited and reeled another one in. You've earned a special place on my trophy wall.

Now that's more like it ... it looks like you swallowed my bait as well; hook, line, & sinker! But I'm a 'Catch & Release' sort of guy that prefers re-catching the same fish again and again ;)

Back to it then ... As for my public site it's just a read only DEMO! If you want to use/test the full function site then ask for a login and I'll freely provide one. What you have made clear to me is that I don't make it clear that the public site is only a semi-functional DEMO! THANK YOU! That's exactly the feedback I'm looking for!

For now, I have to do this by login because if I didn't then everybody would be overwriting everybody else's jump details and that would really mess with people's minds. As for the 'Now Realized' problem I'll do what I can to correct this ASAP; spelling all of this out in a preface and giving you a place to request a login right then and there!

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)

[bofh 0]

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The vertical speed/distance isn't the problem. That is to say if there were no forward throw from the aircraft, no winds, no drift, and no horizontal movement during your descent you would land directly below where you exited. Your rates of descent or vertical speeds would only help tell you how long it's going to take for you to touch down not where you most probably will touch down.

I think we all understand that. I'm just saying that it is easier for a user of the program to enter the vertical speed instead of some constant that isn't explained. I think I know exactly how the program works, and if I am right, the "drift value" is some constant divided by the vertical speed.

[adrenalin 0]

For those of you who missed my repliy to 'I think it's not working. I think it's not user friendly. I think I'd use something else.' ... here it is again:

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Now that's more like it ... it looks like you swallowed my bait as well; hook, line, & sinker! But I'm a 'Catch & Release' sort of guy (if that makes any difference) and prefer re-catching the same fish again and again ;)

As for my public site ... it's just a read only DEMO! If you want to use/test the full function site and hopefully provide feedback then ask for a login and I'll freely provide one. What you have now clearly pointed out to me is that I did not make it clear that this is a semi-functional DEMO! THANK YOU! That's exactly the feedback I was looking for!

For now, I have to do this by login because if I didn't then everybody would be overwriting everybody else's jump details and that would really mess with peoples minds. As for the page and the 'Now Realized' problem I'll do what I can to correct this ASAP; spelling all of this out in a preface and giving you a place to request a login right on the page!

Bet he thought I wouldn't have a copy ;)

It's funny how through the night you delete your 2nd post about my site (with details this time) along with my thankful reply (see above). The best part is leaving the original posts in place to make you look good and me look bad. It must be nice to know the moderator.

Again [popsjumper] you show yourself for what you are! You took the bait again but now sadly; there is no 'Catch & Release' for you. You've shown your colors as you turned to run & hide by deleting our posts. Delete this post too if you want, but you and I both know I've got your number and it's a zero.

Hmmm ... I wonder how long it will take you to delete this post ... better hurry, clocks' running ;)

CC: File

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)

[adrenalin 0]

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The "drift value" is some constant divided by the vertical speed.

Actually no .. the drift values for freefall & canopy are the amounts of horizontal drift (in meters) experienced per one thousand feet of vertical travel. These values are multiplied by the speed of the wind at that altitude to produce the total drift experienced. This drift distance along with the wind heading determines the direction of horizontal travel.

For example: If the winds at 5k are 20 knots then the horizontal drift from say 5.5k to 4.5k would be 60 meters (constant of 3 meters * 20 knots = 60 meters). If the winds are out of the East at 5.5k then you would be pushed 60 meters to the West by the time you fell from 5.5k to 4.5k (assuming you were not trying to move horizontally).

Please note that the suggested drift values of 3 and 28 came from standard military skydives where they don't attempt to move around horizontally and have big floaty parachutes. For us skydivers we not only move around horizontally we also move around vertically and have zippy fast canopies.

Head down jumpers move even faster in freefall so their drift constant is less ... say 2 or possibly 1 (really fast fallers are exposed to the winds for a shorter time and are therefore pushed less). Tandems on the other hand fall at about the same as belly fliers so they should stay with a value of 3.

This will help visualize what I'm talking about... http://www.omniskore.com/freefall_drift2.html (Thanks Omniskore!)

At my DZ we stick with 3 for freefall but use 15 to 20 for the canopy when Tandems are not on the load. If they are then we set the canopy value from 20 to 25.

Mostly into developing software these days (web sites, databases, & simulations). At the DZ you'll find me with the other 'vidiots' looking for something to shoot ;)