MAK file

[Olly Betts]

Working through the formats in order of conversion:

On Tue, Sep 11, 2018 at 08:38:26PM +0200, Darek Lubomski wrote:
> Walls file :
[snip]
> #date 2010-07-28
> #segment /340
> #prefix 340
> ;AM
> #note 340 /340
> #flag 340 /GPS Location
> #FIX  340   E13:02.83  N47:31.68333   2015m     ;dm

Even without knowing the details of this format, I can see that's pretty
clearly specifying longitude and latitude, so that's a good start.

> SEF File (Walls export):
[snip]
> #cpoint 340SR - Fixed Points
> #units meters
> #elevunits meters
> #data station(2,12)east(15,16)north(32,16)elev(49,16)
>  340:340                 13.05            47.53          2015.00
> #endcpoint

By my reading of the SEF spec at
http://www.fountainware.com/compass/Documents/SEF.txt this means 13.05m
and 47.53m ("#units meters" is "Unreferenced metres", whereas this
should be "#units geog" for "Geographical (Lat/Long/Elev)" with values
013-02-49.8E and 47-31-41N - see 3.1.1).

> MAK file:
>
> /SEF dir: 340
> #340.DAT,
> 340:340     [m,13.050,47.530,2015.000];

And here there's also no obvious indication that 13.050 and 47.530 are
degrees not metres, and comparing with the examples in the Compass file
format document at
http://www.fountainware.com/compass/HTML_Help/Project_Manager/formatfixed.htm
it seems 13.050 and 47.530 here are in metres.

If you process the MAK file with Compass does it treat this fixed point
as being in metres or degrees?  I'm wondering if this is actually a bug
in Walls' SEF export.

If Compass actually handles this as degrees, then what I really need to
know to allow Survex to handle this is how to tell the above example
from a fixed point in unreferenced metres.

http://www.fountainware.com/compass/HTML_Help/Project_Manager/formatbaseloc.htm
documents how "the Datum used in geographic conversion operations" is
specified, e.g.:

&North American 1983;

But that's not present in your file.

I can't seem to see anything in the documentation there which says how
geographic coordinates are actually specified.

Cheers,
    Olly