[Xastir] Maps, again!

[Curt, WE7U]

On Fri, 22 Oct 2004, John Ronan wrote:

> http://www.megalithomania.com/conversion/
>
> To convert from Irish Grid to Degrees Minutes Seconds and then
> http://www.uky.edu/KGS/gis/converter.htm
>
> to convert to decimal Lat/Long.
>
> I'm wondering what others use to convert to decimal lat/long as I'm
> seeing gaps/slight overlaps in the pictures.

I can convert from deg/min/sec using any calculator, or I can use
the Xastir Coordinate Calculator to give me all of the conversions
at once.


> Bearing in mind that I know little or nothing about maps except that
> they are all a 'projection' of some sort.  Can I assume that as I go
> further and further from the 'point' mentioned above that I will begin
> to see gaps in the projection.

It depends on how your map was created.  If you switch to some sort
of vector data instead of digitized images, you'll be much better
off.  Also if you stick to smallish images and have Xastir tile them
for you, you'll end up with smaller errors overall.

--
Curt, WE7U			         http://www.eskimo.com/~archer
"Lotto:    A tax on people who are bad at math." -- unknown
"Windows:  Microsoft's tax on computer illiterates." -- WE7U
"The world DOES revolve around me:  I picked the coordinate system!"