[ArcheOS] R: Re: R: GPS track to polygon

albertocosner@libero.it albertocosner@libero.it
Gio 17 Apr 2014 12:57:51 CEST

even more I'll prefer points!
1) If you recognize a SU unit during the survey you mark it, if the border of 
the unit is short you mark all the border, if is too long another day of survey 
will certainly walk trough that border and will mark it,
 if you use a track instead of a point you are constrained to stay in a path 
to mark all the border of the unit, and you will cannot mark finds that is 
close to the path but out of the border. 
2) Is easier play with the Z within points, all the finds is a Z data easily 
compare to the Z data of the border (same kind of data).
3) And you will see that the "current track" (without overwrite the track or 
delete it) recorded during the survey is really useful, is like a memo for the 
marked points.
Viva i punti!

>----Messaggio originale----
>Da: dncgst@gnewarchaeology.it
>Data: 17/04/2014 13.33
>A: "albertocosner@libero.it"<albertocosner@libero.it>
>Cc: "ArcheOS user"<archeos@lists.linux.it>
>Ogg: Re: R: [ArcheOS] GPS track to polygon
>Ciao Alberto,
>thanks for your suggestion. I will try v.hull, specially preserving the
>z value.
>Some more explanation:
>We plan the area before, but on the field we want to define the bounding
>box of the survey unit, because on the field we have a better view of
>the geological and sediment characteristics. At the same time, we survey
>the area as usual, marking point for finds. (However, without finds, we
>want to map the survey unit)
>We survey a geological complex region in Greece, a very dynamic
>landscape, with a lot of faults and geo-horizons changes. We specially
>look for profiles / exposed sections, searching for paleolithic
>stratified finds.
>Then, I would like to preserve the 3 dimension of the survey unit
>polygon, mapping also vertical sections and inner points.
>Thanks for comment!
>In the database, SU table in related to Site/Find table (1 to many).
>On 04/17/2014 10:09 AM, albertocosner@libero.it wrote:
>> Why not a simple convex hull?, v.hull in grass (http://grass.osgeo.
>> org/grass64/manuals/v.hull.html)
>> In my experience, when you survey something, is easier to record gps data 
>> one direction not in circles... (the direction and the extent of the 
>> area was planned before), then is better record point data with different 
>> attributes instead of track with attribute.
>> ciao
>> a
>>> ----Messaggio originale----
>>> Da: dncgst@gnewarchaeology.it
>>> Data: 17/04/2014 2.03
>>> A: "ArcheOS user"<archeos@lists.linux.it>
>>> Ogg: [ArcheOS] GPS track to polygon
>>> Hi all,
>>> now I'm quite confused and I'm not sure if this is the right list, but I
>>> would like to present an archaeological/methodological problem that is
>>> not related to a development issue.
>>> In few weeks I will leave the office for my first survey season and I'm
>>> trying to change something in the methodology adopted in the past by the
>>> project.
>>> I've first created a spatial database to collect data from the survey,
>>> and I'm now thinking about the workflow in the management of GPS data.
>>> To be brief, we define a survey unit an area with unique geological and
>>> macro-sedimentological characteristics. I want to import in the database
>>> the polygon geometry of the survey unit, and I want to do in the table
>>> of attributes of the SU.
>>> We use an handheld GPS (GARMIN GPSmap62). A walk around the SU tracks
>>> the bounding box of the SU.
>>> How to transform the GPS track in a polygon?
>>> I tried this workflow, but I'm sure that you can improve it.
>>> http://www.wiki.gnewarchaeology.it/w/GPS_2D_polygons
>>> Suggestions and critics are welcome!
>>> Thanks,
>>> -- 
>>> Domenico Giusti <dncgst@gnewarchaeology.it>
>>> GPG keyID: 2048R/A3AB7054F6E5D778
>>> -- 
>>> Mailing list info: http://lists.linux.it/listinfo/archeos
>Domenico Giusti <dncgst@gnewarchaeology.it>
>GPG keyID: 2048R/A3AB7054F6E5D778

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