View Single Post
Old September 29th 16, 09:05 AM posted to sci.geo.satellite-nav
Terry Pinnell[_3_]
external usenet poster
Posts: 9
Default Puzzling change in trackpoint rate

Alan Browne wrote:

On 2016-09-28 04:40, Terry Pinnell wrote:
Alan Browne wrote:

(BTW, no altimeter on the iPhone.)

Yes, there definitely is an altimeter on the iPhone 6S+. And various
apps read it. And the Health App should be able to estimate your climbing.

You're right, of course, what I meant to say was no altimeter used by
the iPhone GPS apps I use, Memory Map and Pocket Earth.

You can run several apps at once. As long as they work in BG, there's
probably something that can record the altitude profile. I use a
separate GPS (photologger) and it has altitude (GPS) as well as position
and so on.

I'm heavily committed to Mem-Map and my iPhone but anyway I don't know
of an iOS GPS app that records altimeter-based altitudes as well as
x,y positions. Nor one that reports gross asc/desc for a track, which
would be a useful supplementary estimate.

I like the hat idea, although I suspect I'd quickly lose my iPhone!
Used to have my ancient Garmin strapped to my rucksack, so maybe I'll
try that again.

As high up as possible.

FWIW, here's a screenshot of the GPS record of a short walk yesterday,

No link.

Sorry, finger trouble. Here it is:

opened in GE. My iPhone was in a shoulder pocket. I'm guessing that
the great variation in the density of the trackpoints depends on how
open or wooded it is. There were no fewer than 2,166 points recorded
in this 4.3 mile walk.

That's a point for every 3 metres of travel or about every 2 seconds at
a good walking speed.

Yes, which was the key point in my opening post, with its table
comparing recent and earlier results.

Leaving aside the question as to whether a high or low recording rate
is 'good' or 'bad' (I'm coming around to 'good'), that remains a

Terry, East Grinstead, UK