AnswerID: 269704 Submitted: Friday, Nov 02, 2007 at 11:54
swampy66
replied:
Remember, the whole world does not have to be in Degrees,Minutes and whatever.
That might have been handy back in William
Dampier's day - but its not all that hard to put your
Gps, Ozi, Google Earth, Natmap etc in metres. most maps have had metric grids and co-ords for the last 30 years.
I find it much easier to picture how far 823m is than trying to figure out how far 0.354" are. And at least 823m is always the same length, unlike 0.354" which varies as you travel from
Darwin to Tazzie
Good Luck
Reply 2 of 5
FollowupID: 532580 Submitted:
Friday, Nov 02, 2007 at 13:02
swampy66 posted:
Matt,
0.354" lat at
Darwin is 11m .354"lat and at Hobart its 8m
1'00" lat at
Darwin is 1.85 km and at Hobart its 1.36 km
Longs doesn't vary at all. Only Lats.
This obviously gets much less in Antarctica.
Good Luck - it looks like you'll get more
miles to the gallon in the north.
FollowUp 2 of 5
FollowupID: 532596 Submitted:
Friday, Nov 02, 2007 at 14:26
Member - Matt M (ACT) posted:
Swampy,
I sit corrected, but I think you have it bass ackwards. The distance between lines of latitude varies very little and only due to the fact that the earth is not a perfect sphere (an oblique spheroid) meaning that lines of latutude subtend a smaller arc at the equator than they do at the poles. In any case it is small enough to be insignificant for most applications.
The distance between lines of longitude however does vary more significantly. Unlike lines of latitude, longitudinal lines are not parallel and converge at the poles meaning they subtend a greater arc at the equator and down to zero at the poles.
Cheers,
Matt.
 Click Image to Enlarge |
| Life's a beach.... |
FollowUp 3 of 5
FollowupID: 532603 Submitted:
Friday, Nov 02, 2007 at 15:27
Member - Toolman (VIC) posted:
Swampy,
you raise a good point but one difference between using geographic coords (lats & longs ) versus Grids coord ( metres) is that geographic coordintes are unique to one location on earth whereas if you quote
grid coordinates you need to also quote the correct Zone, because the same
grid coordinates do exist in any one of the 7 zones in
Australia and so on.
Toolman
FollowUp 5 of 5