In article <gH1LPBAUdK04Ew9x@...>, Roger Barker
<roger@...> writes
From: Roger Barker <roger@...>
In article <200003160310_MC2-9D4B-1AD1@...>, Brian Davies
<brian_j_davies@...> writes
From: Brian Davies <brian_j_davies@...>
[snip]
All this requires maps of some accuracy. The ones I have at present will
not do, for example travelling 9 miles last evening , my destination put me
on the Northern side of the M25 whereas I was on the Southern side - on the
map my position was around 2 - 3 miles out.
The UK maps supplied with UI-View were all made from the Attica atlas.
The Boston map locates me with great precision. All my other maps made
from that atlas are similarly accurate, I have never seen an error
remotely approaching 2 to 3 miles.
Agreed. I too use the Attica, and my most detailed map covers a distance
of 8 miles from top to bottom. When testing the map's accuracy, by
driving in opposite directions on the same road, it was easy to see
which side of the road I was on. The greatest inaccuracy was just a few
tens of feet, not 2-3 miles.
However, I have also tried using Info Map 98, which shows my home QTH
about half a mile west from where it really is. Totally useless. I'm
returning the package to where I bought it from.
Look out for version 2 of the Attica package at rallies. It's not the
latest, but it's probably entirely adequate for APRS. I saw several CD
vendors selling it at Picketts Lock on Sunday for around GBP 9.00.
73
Ian, G3NRW
Technical Editor, APRS Protocol Specification
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| APRS on 144.800 [IO91SX] ~55km/35 miles NNW of London |
| email: g3nrw@... |
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| APRS PROTOCOL SPEC:
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