[LINK] limits of technology in finding someone

[Adam Todd]

At 03:25 PM 8/12/2006, Roger Clarke wrote:
>At 14:28 +1100 8/12/06, Danny Yee wrote:
>>I had an interesting experience the first time I was on a bushwalk
>>where the leader had a GPS.  ...
>
>I've asked a couple of people to use GPS to nail down the height 
>difference between my house and the trig on the ridge about 250-300 metres 
>away as the crow flies, and 600 paces in 5 mins 40 secs +/- 10 secs.
>
>No-one's managed to get a decent reading at the house (which has a clear 
>northerly view,

Apparently you need a clear southerly view in Australia.  I know nothing 
really, I just read about this whilst trying to work out why I get no GPS 
readings from the back of my house.  One day when I have time I'll get more 
into GPS and the likes.

>and is 100m above lake-level).  Remarkably, there's also been difficulties 
>getting a consistent reading on top of the trig, which is treeless (and 
>blessedly telecomms-towerless) and has vistas in all directions.

That's amazing really.  I usually have 7-9 satellites covering me anywhere 
in Sydney and the logs to Gosford show great coverage too.

>I'll stick with the 650m to 725m that I estimate from the local 1:100,000.
>
>The 1:25,000 says 727m, but the house elevation I don't know, because 
>within the built-up area the contours are smothered by the cartographer's 
>ridiculous preference for block-boundaries and colour over topographical 
>information.

If you are flying over, go 750 to be safe :)