Tracking speeds

[milkybar 0]

Back tracking my Neptune usually reads in the 90's mph. Recently it read 85mph at 6k. Interested in others' readings. Is this realistic/accurate? No Birdpantz, just tracksuit bottoms, long sleeve shirt.
Ebygum - Can your belly touch your ...? Do your ..... hang down and drag along the ground?

[Staso 0]

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Back tracking my Neptune usually reads in the 90's mph. Recently it read 85mph at 6k. Interested in others' readings. Is this realistic/accurate? No Birdpantz, just tracksuit bottoms, long sleeve shirt.
Ebygum - Can your belly touch your ...? Do your ..... hang down and drag along the ground?

it's realistic. i got low 80-ies tracking in tight nylon suit. there is always a question about pro-track/neptune placement and how speed readings are effected by changing body position.

stan

--
it's not about defying gravity; it's how hard you can abuse it. speed skydiving it is ...
Speed Skydiving Forum

[VectorBoy 0]

Those are the same numbers I get. If you are six foot tall and weigh 150 pounds and have hollow bones you will get better numbers.

[randu 0]

But what about forward speed when tracking? Everybody is talking about vertical speed, but I haven't seen any info yet what forward speed you can reach when tracking?

[champu 1]

to calculate forward speed you either have to do estimate calculations based on exit and deployment locations. or use some kinda of gps data logger (reviever mounted on leg perhaps?)

altimeters like the protrack, neptune, and skytronic do not have enough information available to them to give any kind of forward speed measurement.

you might do a search in the wingsuit forum to see some of the methods they employ to get forward speed readings.

[gus 1]

Unfortunately even gps can't give you your forward airspeed, only your groundspeed. So you either need to know the wind speed and direction (and adjust your readings accordingly) or you need to jump in absolute nil winds!

Gus

OutpatientsOnline.com

[nacmacfeegle 0]

"even gps can't give you your forward airspeed, only your groundspeed."

I know how I would do it, but do you think there's any money in it?

--------------------

He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. Thomas Jefferson

[gus 1]

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I know how I would do it, but do you think there's any money in it?

I sir will give you £0.01 and if everyone else in the world does too you'll be a rich man.

Does your solution involve a pitot tube?

Gus

OutpatientsOnline.com

[riddler 0]

Just want to point out to make sure you are using the latest Neptune software. I've seen that the 1.1 software can be way off in freefall speeds. 85-95 sounds like a pretty reasonable number, though.

Trapped on the surface of a sphere. XKCD

[sdgregory 0]

Question, how do you install updated software in the Neptune?

[Kramer 0]

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Those are the same numbers I get. If you are six foot tall and weigh 150 pounds and have hollow bones you will get better numbers.

Woohoo!!!

Tracking related question: How fast are you tracking horizonally?

The FAKE KRAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAMER!!!!!!!!!

[IanHarrop 42]

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Question, how do you install updated software in the Neptune?

Its all on the Alti-2 site...

http://www.alti-2.com/neptune_updater.htm

"Where troubles melt like lemon drops, away above the chimney tops, that's where you'll find me" Dorothy

[VectorBoy 0]

I'm not fond of GPS technology at the hand held or user carryable size package. I've been hiking and have compared several type of units to each other and they couldn't agree with each other on location or altitude. A topo map and lensatic compass proved they were all very very off! And we were standing still on a mountain top not flying along at 100 mph horizontally or vertically.

I can't speak for the stuff thats available to military units that the public can't get but for the most part the only units I really trust are aviation level units. And the only ones I trust to give me three axis info would be "panel mounted" and certified for use on IFR approaches.

I feel the pain for my wingsuit buddies that are playing with GPS tracking. They may be impressed with the numbers they are getting but you know the saying garbage in garbage out.

[Praetorian 1]

some of that might not be the reciever, the GPS sats are military and carry some encryption designed to make it hard for opponents of the US to use them to accuratly guide their troops/weapons the way we do. As I understand it thats why your GPS location is "aproximate"

Good Judgment comes from experience...a lot of experience comes from bad
judgment.

[pilotdave 0]

That is a system called selective availability, and it was shut off a few years ago. The military still has some tricks up their sleeves to increase accuracy of their systems, but for the most part ours are pretty good in 2 dimensions (within 15 feet usually) and ok in the third.

Dave

[VectorBoy 0]

Dave, when you say ours do you mean an aviation quality approach certified panel mounted unit? Because the hand helds we tested in the field were thousands of feet off in altitude and several hundred feet off horizontally, which is to say junk numbers in my book. And remember standing still on a mountain top with no interferance. Those units would have had a much harder time providing numbers if we were actually moving in any direction at any speed let alone several hundred feet per second.

[Jethers203 0]

Ok, I am a little confused.

At what point in a normal skydive (belly to earth)would the Pro Track record your max speed? I always thought it was the tracking at the end of the dive that would be your max speed. But, this speed is more horizontel then vertical, right?

Someone clear this up for me. My neptune is on the way and I would like to know for my own sake.

Clint D-24352

[mjosparky 4]

I have a Magellan Map 330 and have found it to be extremely accurate. I am usually + or - 10 to 15 feet off on location and + or - 15 to 20 feet in altitude. I think thats pretty good for something that runs off of 2 AA batteries and can fit in my shirt pocket.
Sparky

My idea of a fair fight is clubbing baby seals

[gus 1]

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At what point in a normal skydive (belly to earth)would the Pro Track record your max speed?

The max speed that the ProTrack reports isn't from a fixed point in the jump it's simply the highest (vertical) speed you reached whilst in freefall. Maybe that was at the top end whilst diving down to a formation, maybe it was in the middle when the formation funnelled or maybe it was from the end when you went in to a steep track. Or maybe none of the above!

Both the ProTrack and Neptune deal only in vertical speeds because all they can measure is air pressure and how quickly it's changing.

Gus

OutpatientsOnline.com

[jakee 1,563]

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Both the ProTrack and Neptune deal only in vertical speeds because all they can measure is air pressure and how quickly it's changing.

Thats static pressure only and not dynamic right?

Edit: Of course it's not dynamic it's inside a bloody helmet. I should think these things through first.

Do you want to have an ideagasm?

[kallend 2,106]

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I'm not fond of GPS technology at the hand held or user carryable size package. I've been hiking and have compared several type of units to each other and they couldn't agree with each other on location or altitude. A topo map and lensatic compass proved they were all very very off! And we were standing still on a mountain top not flying along at 100 mph horizontally or vertically.

I can't speak for the stuff thats available to military units that the public can't get but for the most part the only units I really trust are aviation level units. And the only ones I trust to give me three axis info would be "panel mounted" and certified for use on IFR approaches.

I feel the pain for my wingsuit buddies that are playing with GPS tracking. They may be impressed with the numbers they are getting but you know the saying garbage in garbage out.

I find that strange. I have a hand-held Garmin that is usually accurate to about 150ft altitude and better than 50ft in horizontal position. I use it in my plane and it shows me on the taxiway when I'm on the taxiway, and it shows me on the runway threshhold when I'm on the runway threshhold. The altitude datum is not so good, but it is still always within a couple hundred ft of the reading on my (calibrated) airplane altimeter.

...

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

[Jethers203 0]

Ok. Well then it is safe to say that if you are doing a 4 way out of a cessna, launching the formation, the max speed would be the track.

Also, if you are filming a tandem with an average speed of 105mph SAS, then the fastest part of the dive would be if you were to leave the tandem and track away.

It has been my experience that the track is normally the fastest part of the dive if you are doing belly to earth flying. I usually hit around 140 mph SAS on my protrack after a 4 way. Is this 140 mph because of the track? Is it because I am going 140 mph horizontel or vertical? I would like to think it was horizontel.

Let me know.

Clint

[Remster 30]

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Well then it is safe to say that if you are doing a 4 way out of a cessna, launching the formation, the max speed would be the track.

No. You should not speed up vertically during your track. Many people actually slow down their fall rate during it. If you speed up to 140 during your track, then you need to practice it.

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Is this 140 mph because of the track? Is it because I am going 140 mph horizontel or vertical? I would like to think it was horizontel.

Again, no. These devices only record vertical speed by measuring pressure variations. Horizontal speed has no efect on them (unless someone tells me the delta P due to the acceleration at the start of the track would be in the range, but I seriously doubt it)

Remster

[Jethers203 0]

Well, I assure you, there is nothing wrong with my track. I have seen it on video a hundred times and it is nice and flat.

The reason behind my posts were to see at what point in a dive (belly to earth) would the max speed be recorded. Doesn't the pro track only record speeds starting 15 seconds after exit? That is why hop and pops are usually not recorded with speeds.

So, when in a 4 way would the max speed be recorded?

Still curious.

Clint D-24352

[kallend 2,106]

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Well, I assure you, there is nothing wrong with my track. I have seen it on video a hundred times and it is nice and flat.

The reason behind my posts were to see at what point in a dive (belly to earth) would the max speed be recorded. Doesn't the pro track only record speeds starting 15 seconds after exit? That is why hop and pops are usually not recorded with speeds.

So, when in a 4 way would the max speed be recorded?

Still curious.

Clint D-24352

When I do 4-way (or pretty much any RW), the slowest part of the skydive is the track off. I slow down from 120 to around 85mph.

I have seen a number of people who claim to flat-track, but in fact do a diving track (I watch them dropping below me). Maybe this is what you do. You can't tell in a video from above, you really need to see it from the side.

...

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