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Re: Coordinates from iPhone

Subject: Re: Coordinates from iPhone
From: "Peter Shute" pshute2
Date: Fri Jun 28, 2013 6:53 am ((PDT))
I had a very brief play with using the iPhone to relocate a position this m=
orning, and it was about 20m out, indicating that recording to the nearest =
second wouldn't lose much information. I suspect there would be many cases =
where it would do better than that, but I think until the MotionX authors a=
dd an extra decimal place to the display, I won't trouble myself about it. =
Doesn't seem worth the effort of going with an undesirable format or seekin=
g out a different app in order to record precision that's only there someti=

I will make a point of recording a waypoint as well to help relocate my gea=
r, so that will use the full available precision anyway.

Changing the subject, interesting that you mention panoramic photography, K=
eith. I've been interested in it for years too, although not to anything li=
ke the extent you seem to have been. I wonder if people who are interested =
in it also tend to be interested in nature recording. They seem to go toget=
her - record the sounds, record the view.

My early attempts at building a rotating film camera were interesting but i=
mpractical, and were abandoned when the stitching of digital photos became =
practical. Now I just use the panorama mode on my iPhone, and I get a reaso=
nable result. I've also tried a free app called Photosynth, which stitches =
in multiple rows of photos to allow greater vertical coverage, although it =
can mess up the stitching if you aren't careful about rotating about the le=
ns nodal point.

Peter Shute

> -----Original Message-----
> From: 
>  On Behalf Of Keith Smith
> Sent: Wednesday, 26 June 2013 2:39 PM
> To: 
> Subject: Re: [Nature Recordists] Re: Coordinates from iPhone
> Hi Peter,
> I went through a bit of this several years ago, shooting
> panoramas of the eastern faces of the Rocky Mountains west of
> Calgary. I was using a Garmin 60CSx and a 1" optical
> theodolite to triangulate and identify very distant peaks,
> sometimes 120km away behind other peaks 40 to 60km away. I'm
> no mountain climber, so finding good viewing points in the
> foothills with views in great depth required a lot of hunting
> and then understanding what I was seeing (again in great
> depth) required many hours spent with top maps on the computer.
> My constant enemy was 'station eccentricity' which is the
> inability to reliably establish the position of the
> instrument and therefore having to consider that as somewhere
> within a circle of radius x. Even with fairly reliable
> backsights, the results were often less than convincing. By mid
> 2009 the financial crash reduced my income to the point where
> I was put out of my misery by the price of fuel.
> The 60CSx does offer some 'averaging' to increase the odds of
> a good fix.
> At the time, I was discussing rentals of pro grade 'static
> gps' units from my survey supplier who was interested in the
> project and prepared to make the rate very attractive. These
> units need to collect data for an hour or more and then need
> significant post processing to get to anything closer than a
> metre, but can get down much finer than that with more data.
> To do much better you need to tie into a terrestrial network
> (which seems to presuppose that you're part of the surveying
> community).
> Before I packed it up, I was looking at the Ashcroft Mobile
> Mapper, sold by Magellan along with their post-processing
> software. It looked promising, but at 1600 CAD it was a
> bigger bite than I could afford. It does promise 1 metre, though.
> My Galaxy S3 seems pretty good (with Trimble Outdoors), but I
> haven't compared it seriously with the Garmin. Personally, I
> hate these telephone user interfaces and only use them to
> track an occasional hike or find my way to an address
> somewhere. I'm not sure if the repeatability is better 'at
> home' where it can find a few cell towers. I haven't found it
> so impressive in 'fringe areas'. Heh, when you're out
> *there*, then it can't download the bloody maps anyway, and
> the ones you have cached are always missing in a useful scale.
> Software is another challenge. My fav's are ExpertGPS and
> OziExplorer. I use both with geotiff maps which can be
> downloaded free in most countries these days, I think. I was
> able to provoke the EGPS developer to show 0.1"
> but it didn't solve my problems, as indicated above. The
> Garmin software is great for loading maps into the handset,
> but they do remove a fair bit of data (often structures etc.)
> to get the file sizes down.
> Having run a machine shop for a decade with another spent in
> steel fabrication, I think I can say with some confidence
> that consumer GPS is the best example of 'Precision Without
> Accuracy' that I have ever seen.
> They're wonderful devices and I love them but they won't
> thread a needle er, well, they can't do it twice!
> best
> Keith
> --
> Keith Smith - Freelance Guitarist & Location Recording
> Service<>

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