Quick question about Alti-2 N3 logged speed

[Di0 2]

Hello Folks,
I have been jumping with an N3 for a few jumps now and I noticed that it tends to log freefall speed that are, well, quite larger than I expected.

I am a very thiny guy, I only do belly and belly RW, absolutely no freefly, head down and stuff like that. Everybody complains I fall a bit slow (although for the most part, I think it's psychological, since they see me small and my lack of skill to adjust my freefall with respect to the formation properly just yet, once I sort things out I expect my freefall speed to be just average), but anyway, I'm digressing.

If you see one logged jump here as an example:
http://jumplog.net/jump.php?user=Daniele%20Tancredi&jumpNo=36

and the jump chart here:
http://jumplog.net/profileChart.php?jumpNo=36&user=Daniele%20Tancredi

To pick this one, I see spikes of well over 300mph of vertical velocity. Pretty much every jump I do, records speed in excess of 220mph to 250 mph and so on (you can see more jumps if you want, but it's pretty constant), and sometimes it doesn't really seem like a spy but they are quite a few data points logged at that speed.

I know those spikes are flukes, they must be, but since I am very unfamiliar with this type of equipment, I wanted to ask: are they common on this freefall speed logger? Do you see them on yours as well? Or there is something wrong with mine in particular? It's the first time I use this type of things applied to skydiving so I really don't know the characteristics and what to expect.

Thanks a lot for any reply you could provide,
I just want to make sure my N3 works and logs fine!

I'm standing on the edge
With a vision in my head
My body screams release me
My dreams they must be fed... You're in flight.

[Di0 2]

Nobody out there to tell me if those logs look normal or if my 3 is a bit off?

Either that or I deserve the most boring/most useless thread award! :)

I'm standing on the edge
With a vision in my head
My body screams release me
My dreams they must be fed... You're in flight.

[GLIDEANGLE 1]

Try this for an answer:

http://forum.altimaster.com/content.php?176-contact

The choices we make have consequences, for us & for others!

[Di0 2]

GLIDEANGLE

Try this for an answer:

http://forum.altimaster.com/content.php?176-contact

Thanks, I just shot them an email, I'd have preferred a quick experience from another person that has the same product, but... hey! This works too. :)

I'm standing on the edge
With a vision in my head
My body screams release me
My dreams they must be fed... You're in flight.

[pchapman 279]

I can't answer your question specifically about an N3 on a wrist (I assume). You'd think someone else would have info.

But spikes from changing angles of flight can happen, presumably especially when the device is more exposed to the airflow. I have a ProTrack on an external helmet mount, using an open clip. Every time I track off from a belly formation, it shows a spike to 160 mph vertically or similar. That clearly is an artifact and not a sign of horrible tracking.

Your chart did show multiple spikes though, during what I guess is plain belly flying. It's messy enough that there's really no usable data left...

[Di0 2]

Thank you, pchapman.
Your assumption is correct, I use it on a wrist mount and I didn't think about the possible influence of dynamic pressure (you'd think that altis are more resilient to those changes and measure only static pressure more effectively?).

My problem is that every single jump I make (plain belly, right, some beginner's RW), is full to those spike, and as you say there isn't much data left. They're ALL very wide continuous oscillations between super-slow speeds and super-fast speed.
I'd like to answer the simple question "what is my freefall average speed?" but go figure with those very noisy charts.

The problem of relative wind, I didn't consider. This weekend I'll give it a try and use it in my helmet as audible, to see if it logs cleaner data. I barely look at it in freefall anyway, but I'm really going to miss it under canopy. Or maybe see if I can stick it under the sleeve of my jumpsuit and uncover it once under canopy. FOR SCIENCE!!:D

Hopefully Alti-2 will tell me if those noisy charts are somehow normal, I'll post the answer if/when I get one.

I'm standing on the edge
With a vision in my head
My body screams release me
My dreams they must be fed... You're in flight.

[cazzercam 0]

put it in your helmet and it will be fine

I had mine on my wrist, said I hit 232mph at 6k, turns out it was the change when tracking.

once in helmet it will be fine, set the canopy alarms to good distances and you will be fine under canopy anyway.