Brian I'd approach this from the bottom up.
You asked about gps accuracy and - I don't think your garmin would cut it. Personally I would use the most accurate gps you can get which is rtk gps using a post processed base station (the data is processed using your data plus data collected at fixed reference stations throughout the local region). I'd also survey your fixed sensors using a local projection for greatest field accuracy, converting them to lat/long or fuller later. Please keep the comments coming because I'm fascinated as to why you are using this particular method of storing data. On 7/5/08, Brian Grant <[EMAIL PROTECTED]> wrote: > Hi Michael - I'm not sure I'm distinguishing theory from practice (or > what's practical) - maybe this thought exercise is between the two > overlapping spheres. > > What's pragmatic covers a lot of stuff; my use here is utilitarian and > not necessarily deciding about what's "real" or "true" - I just need a > tool for structuring data > and points and polygons are not practical for me. > > I need a simple framework to associate geo-spatial location with > measured attributes. Right now that framework is just a theory with a > pragmatic need to test it among many minds who think in geo-spatial terms > > and aren't afraid to write them down and share it with each other. > > > - Brian > > > michael gould wrote: >> Brian: I wonder what is pragmatic (or do you mean practical?) about the >> below exercise. Pragmatics is another thing...proposed by a practicing >> geodesist (CS Peirce) by the way...aimed at truth testing. >> >> And then I agree with Paul (see message 2 below), that categorization is, >> uh, rather important to knowledge. I recommend George Lakoff's "Women, >> fire >> and dangerous things" on the subject (if bored, skip to chapter 16). By >> the >> ways categories do not need to be fixed, but can also be graded. The Pope >> may not be a bachelor if a fixed definition is used, however his >> bachelorness can be quite high all the same :-) >> >> -- >> >> Message: 1 >> Date: Fri, 04 Jul 2008 10:17:23 -0400 >> From: Brian Grant <[EMAIL PROTECTED]> >> Subject: [Geowanking] pragmatic exercise >> To: [email protected] >> Message-ID: <[EMAIL PROTECTED]> >> Content-Type: text/plain; charset=ISO-8859-1; format=flowed >> >> as a pragmatic exercise allow me to start with a map and end with a >> database >> schema. >> >> begin with a Fuller projection >> (http://en.wikipedia.org/wiki/Fuller_projection) an icosahedral framework >> of >> 20 triangular areas (actually tetrahedra to the center - but we'll leave >> that out for now). Each triangular area is designated a Major Triad. >> >> Each Major Triad is subdivided ** by the same base as the original sphere >> ** >> into 400 Minor Triads (20^2). If the edge of a Major Triad is 8,000 km the >> edges of the Minor Triads are 400 km. Major Triads are designated with >> characters A through T; Minor Triads are designated AA through TT. >> >> Minor Triads are further subdivided into Trixels (or whatever) again by >> the >> same base creating a recursive triangular mesh capable of defining unique >> triangular regions 2.5 m on edge with 13 characters. >> >> Forgive me as it may be apparent by now that I'm not a geographer. I'm an >> application engineer that builds wireless sensor networks and needs a >> place >> to store data based on sensor location - sometimes static - sometimes >> mobile. I've got networks in the US, Pacific islands, India and Europe. >> This >> Recursive Triangular Mesh is what I'm using to do it. >> >> The database schema is nothing more than a wiki with a directory structure >> that looks like "D/FH/KP/ET/SA/RO" - addressing a unique area of less than >> 3 >> square meters directly converted from a Lat/Long point. >> >> My other concern is the precision and accuracy of the location measuring >> instrument - how many digits does my GPS provide? It defines the size of >> the >> final Trixel. >> >> - Brian >> >> >> ------------------------------ >> >> Message: 2 >> Date: Fri, 4 Jul 2008 08:30:48 -0700 >> From: "Paul Ramsey" <[EMAIL PROTECTED]> >> Subject: Re: [Geowanking] polarized light etc >> To: [email protected] >> Message-ID: >> <[EMAIL PROTECTED]> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Ah, you just want to discard all of Western thought back to Aristotle. >> And here I thought you were a wanker. (categorization) >> >> P >> >> On Fri, Jul 4, 2008 at 2:07 AM, stephen white <[EMAIL PROTECTED]> wrote: >>> On 04/07/2008, at 5:24 PM, Will King wrote: >>>> So give us a sample problem, no waffle, Stephen and the pragmatists >>>> on geowanking will probably come up with a pretty good solution. >>> >>> How can we organise all forms of captured information without >>> categorising? Voxels? Turing? Red dots? Layers? >>> >>> That problem has the pre-requisite that you agree that categorisation >>> damages information. >>> >>> -- >>> [EMAIL PROTECTED] >> >> [..cut] >> ______________________________________________ >> Michael Gould >> Dept. Information Systems (LSI) >> Universitat Jaume I, 12071 Castellón, Spain. >> email: gould (at) lsi.uji.es >> www.geoinfo.uji.es >> >> >> >> >> _______________________________________________ >> Geowanking mailing list >> [email protected] >> http://lists.burri.to/mailman/listinfo/geowanking >> >> >> ------------------------------------------------------------------------ >> >> >> No virus found in this incoming message. >> Checked by AVG. >> Version: 8.0.136 / Virus Database: 270.4.5/1536 - Release Date: 7/5/2008 >> 10:15 AM > _______________________________________________ > Geowanking mailing list > [email protected] > http://lists.burri.to/mailman/listinfo/geowanking > -- Sent from Google Mail for mobile | mobile.google.com Will King +44 (0) 77950 96645 _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking
