Applying Geospatially Derived Identifiers in the Real World

Contributed by: 
Elizabeth Green

The advent of smartphones and the use of GPS technology has sky-rocketed in recent years. All of us have had the experience, however, of following the directions provided by the device and finding ourselves “not quite” at the destination. This is often because the geo-coordinates accessed by the device are usually rendered by satellite and represent a general approximation of home or business, not necessarily the “front door”.

Standards from ECCMA (Electronic Commerce Code Management Association), the Open Geospatial Consortium (OGC) and buildingSMART International can be seen as important and synergistic building blocks of modern, location-aware solutions to this and other even more important problems. For example, an international standard or set of standards for communicating information about properties would help rationalize real estate markets around the world and support the development of land tenure systems in the developing world.

The OGC Point of Interest (POI) Standards Working Group is developing a POI encoding standard. POIs are the kind of spatial information most familiar to the mainstream public. They are those named places on maps and in-car navigation systems. In many ways, one could consider POIs a fundamental requirement of any spatial data infrastructure. We also see their importance in the commercial sector for navigation applications and social networks. Considering the ubiquitous need for POI information, surprisingly little effort has gone into international POI standardization. The purpose of the POI SWG is to produce an encoding standard of points of interest data that includes an abstract data model and JSON and XML Schema implementations of that abstract model. 

The author of this blog post is interested in working with others on the OGC POI encoding standard effort and to explore the synergies between ECCMA's property identifier standards and that emerging standard leveraging the Memorandum of Understanding between the organizations signed last summer.

Location identifiers

Identifiers are everywhere. Your driver's license number and social security number are identifiers. From a technology perspective, identifiers are the essential connectors at the heart of database structures, web-interaction and... geography.

Generally speaking, identifiers can be expressed as natural surrogete or compositie:

  1. A surrogate identifier has no business meaning on its own and usually implies a registry.
  2. A natural identifier is formed of attributes that already exist in the real world.
  3. A composite identifier is composed of two or more attributes.

Any of these types of identifier can also be quality Identifiers that enable verification and validation of the issuer of the identifier through data requirements, including the authority of the issuer.

ECCMA is a standards organization focused on quality identifiers and administers the ISO 8000 Standard - Data Quality and Data Requirements. In its long history in supporting the development, cataloging and application of identifiers in the realm of quality master data and data governance, ECCMA has issued standards and tools for managing master data.

In 2014, ECCMA issued a draft of open standardized formulas which generate identifiers based on specific locational points, such as a residence, with an identifier that is created from the conversion of GPS degree or decimal notations into simple text using the ECCMA 1 standard.

ECCMA STANDARD 1 – Real Property Identification

Historically the description of a property was made through the use of natural markers (metes and bounds), and while this is still in use today, a real estate lot boundary is most commonly described by the coordinates of a polygon in a local coordinate system such as State Plane which is itself, at some point, referenced to an Earth coordinate system.

The ECCMA Standard 1 provides an open formula for creating a unique identifier for a specific locational point on the Earth using the latitude and longitude of a given point on the map as a single coordinate, or used together as a collection to represent a section of land. The individual coordinate or X/Y position formula is called Property Natural Identifier Unit (PNIU). The PNIU specifies requirements for identifying a unit space. The identifier is an encoding of the latitude, longitude, and floor (elevation) of the front door or egress of the unit space. It can also be used for marking any component’s location such as utility box, a well, etc.

When read as a collection of points to represent a contiguous area or section of land, typically referred to as a "lot" or "parcel" - Property Natural Identifier Lot (PNIL). These identifiers are defined as "natural identifiers" as they are self-described from their parts: latitude and longitude coordinates, encoded by the ECCMA Standard 1 formula.

The PNIL section of ECCMA-1 specifies a method for generating a PNIL from a boundary representation or the shape of a structure. It also specifies the format for a controlled identifier (an identifier that is arbitrarily assigned and not based on intrinsic characteristics of a lot or structure), and it specifies requirements for organizations that issue controlled identifiers.

The PNIL is not intended to replace any of the existing property identifiers but represents an opportunity to add a standard geospatially interpretable identifier that will make it easy to visualize the boundaries of a property or structure in commonly available geospatial systems, as it uses the OGC KML standard. This union of technologies can provide tremendous benefit to users and purveyors of location-based software solutions.

Next steps

The PNIL/KML connection could be the keystone in the arch that connects the real property world with the larger geospatial technology world. Activity in the OGC POI Standards Working Group  provides an opportunity for diverse location identifier stakeholder domains, including the real property domain, to come together around a common and efficient way of describing locations. This would be profoundly valuable for rationalizing real estate markets around the world and supporting the development of land tenure systems in the developing world.

Ms. Green will be presenting on this topic at the upcoming Information and Data Quality Summit, Tuesday, October 13, 2015. Please visit: http://idqsummit.org/ for more information.

About the Author

Principal Consultant with rel-e-vant Solutions, is a strategist, solutions architect, speaker and valuation advocate. She is a recognized mortgage technology veteran in software product leadership for solutions in residential property valuation and mortgage financing.  Green is helping to foster a new level of understanding in property valuation and collateral risk assessment through the application of digital intelligence.

She is the 5th term chairperson of the MISMO (Mortgage Industry Standards Maintenance Organization) Property and Valuation Services Workgroup and served on the MISMO Education Committee from September 2013 through June 2015.  Additionally, she is a member of the Open Geospatial Consortium and a member of the Board of Directors of the Electronic Commerce Code Management Association (ECCMA).  She holds an ISO 8000 Master Data Quality credential and studied as a residential appraiser. Ms. Green is a 2015 Mortgage Banking Tech All Star.

Contact her at Liz [at] rel-e-vant.com or follow her on Twitter: @freshrelevance