This issue can be solved by acquiring an accurate reading with a sub-meter GPS unit on your site grid's datum and using the affine transformation tools to "move" the site grid data into a projected coordinate system based on the difference between the GPS and site grid coordinates. The accuracy of the transformation depends on the size of your study area. The results were excellent when I used this process for grids a few hectares in size.
The affine transformation tools can be installed from the Plugins menu. Eric On Mon, Jan 28, 2013 at 8:26 PM, Gerardo Jimenez <gej...@hotmail.com> wrote: > Main thing is that QGis only allows you to use cartographic Coordinate > Reference Systems. Most of the time archaeologist (I am one) we use totally > arbitrary CRS. Once I posted a similar question and the answers were that > if I could assign a coordinate in a mapping CRS that should do it (like an > UTM for instance). > Regarding on drawing systems for archaeology, I use acad, but it does lack > the attribute table and its capabilities. My advice will be some how assign > a mapping crs to your data. > > Gerardo Jiménez Delgado > Instituto de Investigaciones Antropológicas > Universidad Nacional Autónoma de México > Ciudad Universitaria s/n > Coyoacan 04510 Mexico City > Mexico 56 22 95 16 > > > To: qgis-user@lists.osgeo.org > > Date: Sun, 27 Jan 2013 22:25:59 +0100 > > From: bernd.vogelges...@gmx.de > > Subject: Re: [Qgis-user] Advice Please > > > > > Hi Bill, > > > > Can it be done? Yes, why not ? > > How? Well, firstly you should ask archeologists how they use whatever > > software to draw archeological features. The basic concepts will be the > > same i guess. > > > > I have no idea of measurement in general and of archealogical > measurement > > in particular, but i will try a wild guess: > > I think that you always have to start from a fix point with known > > coordinates.(Point layer, which coordinate system?) > > From this, you can generate a grid e.g. mesh width 1 m (Vector-> > Research > > Tools -> Vector Grid)(Line or polygon layer) > > > > Then you create your new layer(s) for your feature(classes) and start > > drawing.(Points, lines, polygons?) > > Of course there are dozends of steps to reach that phase, but i can't > > write a book here. > > > > As far as i know Access mdb still isn't supported yet (at least not > > available for beginners with no computer wizadry background), but you > can > > export your tables to dbf format (direct import with drag and drop) or > xls > > (through xytools plugin) > > > > More detailed questions, maybe more detailed answers. > > Maybe others with can drop in ... > > > > Cheers > > Bernd > > > > > > > > Am 27.01.2013, 21:36 Uhr, schrieb Bill Franklin <w.frank...@ntlworld.com > >: > > > > > I'm now getting to grips with Qgis quite well, that is for a newby not > > > used > > > to mapping software and I have a couple of questions I'd like some > > > advice on > > > please. Firstly, I want to be able to draw archaeological features > such > > > as > > > earthworks on to a map. Can this be done and how? > > > > > > > > > Secondly can I use Microsoft access with qgis? I have some data in > access > > > which I would like to load up and map. > > > > > > > > > Any advice much appreciated. > > > > > > > > > Bill Franklin > > > > > > > > > > > > -- > > Bernd Vogelgesang * Siedlerstrasse 2 * 91083 Baiersdorf * > +49-9133-825374 > > _______________________________________________ > > Qgis-user mailing list > > Qgis-user@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/qgis-user > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/qgis-user > >
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