Project

General

Profile

Feature #574

Updated by Stefan Eichert over 8 years ago

Whitepaper Geometries 


 Content 

 Concept 
 1. What types of physical things with locations are there according to the sources 
 1a. How precise or fuzzy is their extend defined 
 1b. Which various possibilites can be observed regarding the identification of an physical object with a spatial position 

 Technical requirements 
 2. What types of geometries are needed to map the spatial extend/position of the objects 

 Technical Details 
 3. Tables used to represent the objects and their location 
 4. Queries and Triggers used to update/delete/insert additional/needed information.  

 UI and Userinput 
 5. Buttons and forms 
 5.1. Add Geometry 


 h1. 1. What types of physical things with locations are there according to the sources 

 I. Physical things like buildings, settlements, regions, areas etc. that have or originally had a position in space and a certain extend 
 II. Roads/routes/rivers that have or originally had a position in space and a certain extend 
 III. Points where for example an archaeological find has been found. 

 h2. 1a. How precise or fuzzy is their extend defined 

 Ad. I. and II.: Either the polygon represents the extend=shape of the physical thing  
 or the original (and no longer known) extend is located within a polygon 
 Ad. III. There is no extend but only a known centerpoint. 


 h2. 1b. Which various possibilites can be observed regarding the identification of a an physical object with a spatial position 

 case 1: The extend is known and can be drawn as a polygon 
 E.g. the shape of a building or the area of excavation or the area of a settlement that can be drawn for example from an aerial photograph or a map. 

 case 2: The extend is not known but known to be within a larger area with known extend that can be drawn as a polygon 
 E.g a no longer existing settlement that is known to have been situated within a known area for example in a valley between two other known settlements. 

 case 3: The extend is not known but known to be within a larger area with unknown extend that cannot be drawn as a polygon 
 E.g. a no longer existing settlement that is known to have been situated within the historical boundaries of a no longer existing county. 


 case 4: Neither the extend nor a vague position within a reasonable larger area are known. 

 In many cases the exact identification of physical things/places mentioned in sources (e.g. in charters or also in archaeological publications) with one certain and still existing physcial entity and its extend is not possible. Therefore it is necessary to allow multiple possibilites to record possible locations of physical things: 
 A If a charter for example may mention mentions one church and today two still existing churches might be identified with the one mentioned. In this case the church-entity from the source should be linked to two possible spatial objects. Here they would be two polygons, representing the extend of the respective church. However, any combination of the above mentioned cases (from 1 to 3) must be possible in any number. In theory it must be possible to link e.g. a castle known from a charter to the very extend of a still existing castle and at the same time to a vanished castle that is known to have been located within a certain area and also to another possible location within a certain administrative unit etc. etc. 


 h1. 2. Spatial Visualisation 

 Each entity with spatial position will be represented on the map at least with a marker as point. If polygon data is available these polygons will be shown depending on the zoom level. 



 The user should be able to  


 h1. 2. What types of geometries are needed to map the spatial extend/position of the objects 

 Polygons and Points 

 h1. 3. Tables used to represent the objects and their location 

 gis.centerpoint 
 gis.polygon 

 h1. 4.  

 h1. 5. Queries and Triggers used to update/delete/insert additional/needed information. 


  

 h1. 6. Buttons and forms 

 h2. 6.1. Add Geometry

Back