[EMAIL PROTECTED] wrote on 06/21/2007 04:24:44 PM:
> > Also, I was hoping to abstract all linear geomtries, not just curves. > > Is this type of abstraction in the module we are discussing? > > > I am not sure; you would need to look at the interfaces here (scroll > down to the geometry section): > - http://geoapi.sourceforge.net/pending/site/apidocs/index.html > > It *is* the raw ISO 19107 Geometry model in Java interface form. > > Is CompositeCurve what you are looking for? I've only been "sorta" following along. I have seen some of your earlier messages about linear referencing. This is not the same thing as linear geometries. I presume you would like to build linear referencing functionality on top of the 19107 geometric objects. W.r.t. the above: in the nomenclature of 19107, all geometries with 1 topological dimension are called "curves". For clarity's sake, could you provide an example of a type of 1D geometry which is not a curve? ISO 19107 is pretty well established, but should also be considered a "basic library" upon which more complex (read: useful) things can be made--exactly like what I think you have in mind. JTS, et. al, is built on simple features for SQL. In ISO world, this is 19125, and is expressed as a "profile" (read: stripped down version) of 19107. Most importantly, both 19107 and 19125 contain plain jane geometric objects. If you want to "do" stuff with them or to them, you write a "service". Secondly, there is a separate notion of "linear referencing" which is beginning to be fleshed out. Here's a synopsis of the activity in ISO from http://www.isotc211.org/pow.htm. I gather you're not enthralled with the standard's development processes, but are open to using standards which currently exist. See below for which are published and which are still under development. ISO 19132 (DIS; prolly published within a year) Geographic information - Location-based services - Reference model The basis of all that follows. ISO 19133 (Published & Available) Geographic information -- Location-based services -- Tracking and navigation "ISO 19133:2005 describes the data types, and operations associated with those types, for the implementation of tracking and navigation services. It is designed to specify web services that can be made available to wireless devices through web-resident proxy applications, but is not restricted to that environment." ISO 19134 (Published & Available) Geographic information -- Location-based services -- Multimodal routing and navigation "ISO 19134:2006 specifies the data types and their associated operations for the implementation of multimodal location-based services for routing and navigation. It is designed to specify web services that may be made available to wireless devices through web-resident proxy applications, but is not limited to that environment. " ISO 19147 (New work item) Geographic information - Location Based Services - Transfer Nodes All over the world, the authorities are facing serious problems due to the steady rise in the traffic volume. This rise will sooner or later call for very dramatic measures, one first step might be to persuade or force car users to change modes partly or entirely. In order to help this process the authorities will need a complete overview of where it is possible to change modes of transportation. A wide range of information or attributes is needed at each node, for example the accessible modes, the scheduled traffic available, the timetables, accessibility for the disabled and more physical descriptions like; are there parking lots, shelters and kiosks available. Also information that will help authorities manage concessionary areas and pricing zones will be of great value. In addition to this; the exact positioning of the node must be known; it must be possible to aggregate nodes and issue unique naming and numbering of nodes. This standard will be based on IS 19134 definitions of MM_TransferNode and MM_Transfer. The semantic of Transfer Nodes in IS 19134 describes a change of travelling mode or transfer in a multimodal network. Along with MM_Transfer it enables multimodal routing. The standardised catalogue will allow authorities and private transport companies to co-operate and share non sensitive information between them. This will allow easier flow of data and in the end it will contribute to a more efficient transport sector. The proposed standard will be deeply tied to the development of ITS (Intelligent Transportation Systems) solution for the public transport. This proposed work should therefore be carried out in close cooperation with ISO/TC 204. ISO 19148 (New work item) Geographic information - Location Based Services - Linear Referencing System There is a growing demand for information that needs to be referenced directly to a linear feature. This is due to the general ever increasing need for location based information reflecting not only points of interest, but also the longitudinal properties of the "carrier feature". There is always a need to negotiate the way between points of interest. This is certainly true for the transportation sector where travelling planners and navigation systems have been domesticated over the last few years. Apparently, it is not enough to provide services to the users of the infrastructure, but also to help maintain and operate the infrastructure itself. Another driver behind the need to standardize LRS's is the widespread use of GIS. This calls for interoperability and correspondence between different kinds of referencing systems. Thus from a geometric/geographical point of view a common LRS should be derived directly from the geometry of the linear feature in question. The idea of the project is to develop a common model that covers the most basic needs to reference all types of linear features. In order for it to be truly versatile, an underlying topological structure of nodes and edges is needed. The topology should be based directly on the geometry of the linear feature itself. The nodes and edges will be uniquely numbered and constitute a very basic geometry based referencing system. Such a model can be derived from existing ISO/TC 211 standards. The model must be able to meet the special challenges of the different modes and domains in which it is to be used. For example within wiring it must cope with the different kinds and purposes of the wires, the fan-out and equipment at junctions. Within pipelines, types and purpose are important in addition to the complex branching, connection valves and splitter boxes. The inherently most mature domain in this respect is transportation. As long as there have been roads and rails some kind of LRSs have always been applied. Normally, these LRS's are based on a linear measurement along the infrastructure from a known starting point usually represented by physical markers along the right-of-way of the feature. Most of these widely used LRS's are considered non-geometrical. Over the years, though, the many challenges of roads, as how to deal with number of lanes, ramps, arms and roundabouts is well understood and solved. Traditionally, the need for LRS in transportation emerge from two independent sources, road maintenance and operation, and the road-user aspect, Intelligent Transportation Systems, ITS. In the mentioned geometrical approach, both needs can be met. Thus this project calls for close cooperation between ISO/TC 204 and ISO/TC 211. There has been, and is currently being done a lot of work, studies and research in this field. A lot of this may be regarded as stepping stones for this standard. The project will take notice of this important work, for example: • Refer to ISO 19133, in witch there is a package witch supplies classes and types to the definition of a LRS. It is naturally to consider this standard as a starting point for work. ... This standard will be based upon IS 19133 and wil done in close co-operation with ISO/TC 204. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Geotools-devel mailing list Geotools-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
