[Crm-sig] Issue 388 measuring position

Martin Doerr martin at ics.forth.gr
Mon Mar 8 10:38:56 EET 2021


Dear Gerald,

Yes, this should be subclass of O21 Measurement. We need further 
elaboration about how measurements relate to the approximation of things 
of interest. I found this to be quite diverse, and adding to this class 
a repetition of all topological relations confusing. E18 still has a 
Presence directly related.

Best,

Martin

On 3/8/2021 10:07 AM, Hiebel, Gerald wrote:
>
> Dear Martin and all,
>
> thanks for taking this forward and the suggested proposition, which 
> defines the process very well.
>
> One question I have is how to relate the Position Measurement to the 
> measured object (E18 or S10).
>
> I believe the E93 Presence is the correct way for it, but we may run 
> into a problem, as E18 is no longer a subclass of E92 and therefore 
> not of E93.
>
> For implementation simplicity a shortcut to a measured object in the 
> form of a specific property would be nice, or could we use O24 measured ?
>
> If so, should we make  Position Measurement  a subclass of O21 
> Measurement and maybe include an example that shows the modelling.
>
> But maybe I did not see an obvious solution.
>
> Best,
>
> Gerald
>
> *From: *Crm-sig <crm-sig-bounces at ics.forth.gr> on behalf of Martin 
> Doerr <martin at ics.forth.gr>
> *Date: *Monday, 1. March 2021 at 21:31
> *To: *crm-sig <Crm-sig at ics.forth.gr>
> *Subject: *[Crm-sig] Issue 388 measuring position
>
> Dear All,
>
> I revise my previous proposal for measuring positions:
>
>
>
> Any position measurement is based
>
> on triangulation with multiples distances to reference points and 
> angle measurements. GPS measures distances to satellites. Distances 
> are Dimensions. If directed distances use georeferenced directions, 
> i.e. angle to the rotation axis of earth, etc. angles
>
> are again dimensions. Hence, a position measurement is an evaluation 
> of a combination of multiple associated distance and angle 
> measurements from a particular spot to certain reference points of 
> known position in the same reference space. If stars are used,
>
> they constitute (extremely) distant reference points. Gravity and 
> Earth Magnetic Field also provide reference directions for angle 
> measurements that do not need a second reference point. Classical 
> longitude measurements use temporal simultaneity of a common
>
> event with a reference location, which evaluates to an angle. All 
> methods are fairly complex, but the details are a standard routine or 
> even hidden in a modern GPS module.
>
> Therefore
>
> we argue that position measurement is a specific (composite) 
> observation which results in a position expression, but the 
> constituent dimensions may or may not be documented.
>
> Hence,
>
> P40 observed dimension (was observed in): E54 Dimension may not be 
> instantiated.
>
> All
>
> position measurements are approximations of other places. Therefore, 
> they result in a declarative place defined by an E94 Space Primitive. 
> Since in general we talk about moving reference spaces, moving things 
> and evolving processes, the time of measurement
>
> is essential. We take it either to be the time-span of the 
> measurement, or a narrower time-span which covers the contributing 
> time-critical observations. In essence, this defines a declarative 
> spacetime box (volume), which again is an approximation. It appears
>
> to me that such an approximation would normally be used to determine 
> parts of the extent of some instance of Presence by overlap, coverage 
> or containment.
>
> Sxxx
>
> Position Measurement
>
> Subclass
>
> of:        E16 Attribute Assignment
>
> Scope
>
> note:     This class comprises activities of measuring positions in 
> space and time. The measured position is intended to approximate a 
> part or all of the extent of the presence (instance of E93 Presence) 
> of an instance of E18 Physical Thing or E4 Period of
>
> interest, such as the outer walls of an excavated settlement, the 
> position of a ship sailing or the start and end of athlete’s run in a 
> competition. Characteristically, a theodolite or GPS device may be 
> positioned on some persistent feature. Measuring the
>
> position of the device will yield an approximation of the position of 
> the feature of interest. Alternatively, some material item may be 
> observed moving through a measured position at a given time.
>
> A
>
> position measurement is an evaluation of a combination of measurement 
> of multiple associated distances and/or angles (instances of E54 
> Dimension) from a particular spot to certain reference points of 
> previously known position in the same reference space.
>
> Often, the observed constituting dimensions are not documented, or 
> hidden in an electronic device software.The measured position is given 
> as an E94 Space Primitive corresponding to a declarative place. 
> Together with the measured time-span covering the time-critical
>
> observations it forms a spacetime volume, which should normally 
> overlap with the spatiotemporal extent of the thing or phenomenon of 
> interest.
>
> Properties:
>
> Oxx1
>
> determined position (was determined by): E94 Space Primitive
>
> Oxx2
>
> has validity time-span (is position validity for): E52 Time-Span
>
> We
>
> may now formulate the approximation to the things of interest, e.g.
>
> Oxx3
>
> overlaps with presence: E93 Presence.
>
> But
>
> the time=span of this presence is already implicit in the time-span of 
> validity.
>
> If
>
> we use:
>
> Oxx3
>
> overlaps with presence of: XXXX, we need a property for E18 and 
> another for E4…
>
> Another
>
> use case is when someone wants to determine if she is at a particular 
> declarative place: Fisherman now mark positions in the sea with GPS, 
> in order to return to the same spot...
>
> --------------------------------------------
>
> Opinions?
>
> To be discussed!
>
> Martin
>
>
> -- 
> ------------------------------------
>   Dr. Martin Doerr
>                
>   Honorary Head of the
>   Center for Cultural Informatics
>   
>   Information Systems Laboratory
>   Institute of Computer Science
>   Foundation for Research and Technology - Hellas (FORTH)
>                    
>   N.Plastira 100, Vassilika Vouton,
>   GR70013 Heraklion,Crete,Greece
>   
>   Vox:+30(2810)391625
>   Email:martin at ics.forth.gr  <mailto:martin at ics.forth.gr>   
>   Web-site:http://www.ics.forth.gr/isl  <http://www.ics.forth.gr/isl>


-- 
------------------------------------
  Dr. Martin Doerr
               
  Honorary Head of the
  Center for Cultural Informatics
  
  Information Systems Laboratory
  Institute of Computer Science
  Foundation for Research and Technology - Hellas (FORTH)
                   
  N.Plastira 100, Vassilika Vouton,
  GR70013 Heraklion,Crete,Greece
  
  Vox:+30(2810)391625
  Email: martin at ics.forth.gr
  Web-site: http://www.ics.forth.gr/isl

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