Issue 612: Diagrams for Position Measurement and properties in the introduction of CRMsci

Starting Date: 
Working Group: 

In the 54th CIDOC CRM & FRBR/LRMoo SIG meeting, the SIG resolved to start a new issue, where to discuss the diagrams and small text descriptions for Position Measurement & properties in the introduction section of CRMsci. 

HW: Athina Kritsotaki, Thanasis Velios. 

Rome, September 2022

Post by Thanasis Velios (22 November 2022)

Dear all,

Athina, Gerald, Martin and I have put together the homework for issue 612. Proposing the following text to be added between the Observation section and the Inference making section at the CRMsci introduction:

Measuring positions
A specialisation of the class S4 Observation is the class S32 Position Measurement. It allows modelling the process of measuring the position of entities based on the fact that they can be observed at a location at a given time-span. The properties connecting the observable entity with time and location are shown in Figure 9.

Figure 10 shows an example of measuring the position of the Titanic after it hit an iceberg. Before issuing a distress signal, Titanic’s captain Smith measured the position of the ship based on the distance travelled from the last known position, but this measurement was inaccurate. The Titanic is an instance of S15 Observable Entity and more specifically an instance of E18 Physical Thing and its spatio-temporal extent during measuring is an instance of E93 Presence. The spatial projection of this instance of E93 Presence is the actual place where the Titanic was after hitting the iceberg. Captain Smith’s measurement was inaccurate and the resulting latitude and longitude coordinates measured (instance of E94 Space Primitive) defined the assumed place of the ship and not the actual place. The assumed place is a separate instance of E53 Place which can only approximate the actual place. The two are connected with the property ‘P189 approximates’ which allows reasoning on different views of the location of things by comparing instances of E53 Place with their corresponding provenance.


Figure 9: Classes and properties for describing measuring the positions of things.

Figure 10: Example of position measurement of the Titanic after it hit an iceberg.

To discuss at the next meeting.

All the best,


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