POSO: A Generic Positioning System Ontology

Maxim Van de Wynckel and Beat Signer

Web & Information Systems Engineering Lab
Vrije Universiteit Brussel

POsitioning System Ontology

Introduction

POSO provides the terminology needed to describe different types of positioning systems, the algorithms and technnologies that they implement and the data that is produced by these systems.

Location-based Services

Location-based Services ...

While a location-based service aims to provide you with a nice clean geographical location, maybe even with some additional context such as the accuracy that can already help to determine the relevancy. The system working behind the scenes has a lot more data available. In addition we do not know how the output of a location-based service was processed. With POSO we aim to describe the process that led to a certain output, which in our case means the description of the system that works behind the scenes and the complete set of data that is can produce. Using this additional information another positioning system knows how to reason on the output or know how to perform high level sensor fusion. It may even be able to use additional data that is not important for the output - but can benefit another system.

Positioning System

When creating the design for our ontology we first identified what actually defines a positioning system. A positioning system is a system that aims to track entities in a certain area. These entities can be objects, persons or basically any spatial thing. We usually deploy this positioning system at the area where this tracking should be done. Weither it is on another planet, a building, an underground metro track or something more abstract like tracking pawns on a physical game board. The system uses various different algorithms and technnologies that are used to track an entity. Each entity on itself has different properties, such their position, their orientation or velocity that are important for the algorithms to determine their position.

Positioning System ...

Satellite positioning systems

Optical positioning systems

Inertial positioning systems

Integrated positioning systems

Indoor positioning systems

Tracked Entities and Their Properties

Aside from being able to describe a positioning system, we also wanted to describe the data they produce in a way that would be usable by other systems. Historical data is important for many positioning systems, so one design criteria was definitely to allow individual observations of a value. The most important types of data for positioning system is a position, orientation and velocity. But the ontology should still allow for extensions of other sensor data if needed. Finally, a system may provide a position with different granularities. For example, you might have a simple system that knows your room based on a QR-code check-in system. The system can report that you are 'In' a certain room until you check out - but at the same time your system also knows that at the second you scan the QR-code you are standing right in front of it.

Ontology Design

Ontology Design ...

POSO Common Module (`posoc`)

`http://purl.org/poso/common/`

Adds common in-use positioning systems and location-based services
- e.g. Global Positioning System, GeolocationAPI
Adds common algorithm implementations
- e.g. HectorSLAM, Trilateration, CSI fingerprinting
- Adds graph shapes for algorithm input and output
Adds common frameworks/platforms
- e.g. IndoorAtlas, AnyPlace
Adds common types of landmarks
- e.g. iBeacon, Eddystone, AltBeacon

Usage

Positioning System

turtle
dbr:Some_Unversity a ssn:Deployment .
<deployment/building_a> a poso:IndoorDeployment, geosparql:Feature ;
    rdfs:label "Building A"@en ;
    geosparql:hasGeometry [ 
        a geosparql:Geometry ;
        geosparql:asWKT "..."^^geosparql:wktLiteral ] .
 
<system/OPS> a poso:LocationBasedService ;
    rdfs:label "Outdoor campus positioning"@en ;
    ssn:hasSubSystem posoc:GPS ;
    ssn:hasDeployment dbr:Some_University .
<system/IPS> a poso:IndoorPositioningSystem ;
    rdfs:label "Indoor campus positioning"@en ;
    ssn:hasDeployment <deployment/building_a> ;
    ssn:implements posoc:KNNFingerprinting .
<system/CampusPositioning> a poso:IntegratedPositioningSystem ;
    rdfs:label "Hybrid campus positioning system"@en ;
    ssn:hasSubSystem  <system/OPS>, <system/IPS> ;
    ssn:implements posoc:WeightedAccuracyFusion .

Usage

Positioning System

turtle
dbr:Some_Unversity a ssn:Deployment .
<deployment/building_a> a poso:IndoorDeployment, geosparql:Feature ;
    rdfs:label "Building A"@en ;
    geosparql:hasGeometry [ 
        a geosparql:Geometry ;
        geosparql:asWKT "..."^^geosparql:wktLiteral ] .
 
<system/OPS> a poso:LocationBasedService ;
    rdfs:label "Outdoor campus positioning"@en ;
    ssn:hasSubSystem posoc:GPS ;
    ssn:hasDeployment dbr:Some_University .
<system/IPS> a poso:IndoorPositioningSystem ;
    rdfs:label "Indoor campus positioning"@en ;
    ssn:hasDeployment <deployment/building_a> ;
    ssn:implements posoc:KNNFingerprinting .
<system/CampusPositioning> a poso:IntegratedPositioningSystem ;
    rdfs:label "Hybrid campus positioning system"@en ;
    ssn:hasSubSystem  <system/OPS>, <system/IPS> ;
    ssn:implements posoc:WeightedAccuracyFusion .

Usage

Positioning System

turtle
dbr:Some_Unversity a ssn:Deployment .
<deployment/building_a> a poso:IndoorDeployment, geosparql:Feature ;
    rdfs:label "Building A"@en ;
    geosparql:hasGeometry [ 
        a geosparql:Geometry ;
        geosparql:asWKT "..."^^geosparql:wktLiteral ] .
 
<system/OPS> a poso:LocationBasedService ;
    rdfs:label "Outdoor campus positioning"@en ;
    ssn:hasSubSystem posoc:GPS ;
    ssn:hasDeployment dbr:Some_University .
<system/IPS> a poso:IndoorPositioningSystem ;
    rdfs:label "Indoor campus positioning"@en ;
    ssn:hasDeployment <deployment/building_a> ;
    ssn:implements posoc:KNNFingerprinting .
<system/CampusPositioning> a poso:IntegratedPositioningSystem ;
    rdfs:label "Hybrid campus positioning system"@en ;
    ssn:hasSubSystem  <system/OPS>, <system/IPS> ;
    ssn:implements posoc:WeightedAccuracyFusion .

Usage

Positioning System

turtle
dbr:Some_Unversity a ssn:Deployment .
<deployment/building_a> a poso:IndoorDeployment, geosparql:Feature ;
    rdfs:label "Building A"@en ;
    geosparql:hasGeometry [ 
        a geosparql:Geometry ;
        geosparql:asWKT "..."^^geosparql:wktLiteral ] .
 
<system/OPS> a poso:LocationBasedService ;
    rdfs:label "Outdoor campus positioning"@en ;
    ssn:hasSubSystem posoc:GPS ;
    ssn:hasDeployment dbr:Some_University .
<system/IPS> a poso:IndoorPositioningSystem ;
    rdfs:label "Indoor campus positioning"@en ;
    ssn:hasDeployment <deployment/building_a> ;
    ssn:implements posoc:KNNFingerprinting .
<system/CampusPositioning> a poso:IntegratedPositioningSystem ;
    rdfs:label "Hybrid campus positioning system"@en ;
    ssn:hasSubSystem  <system/OPS>, <system/IPS> ;
    ssn:implements posoc:WeightedAccuracyFusion .

Usage

Tracked Feature and Properties

turtle
<me> a poso:TrackedFeature, foaf:Person ;
    foaf:name "Maxim Van de Wynckel"@en ;
    poso:hasPosition <me/position> ;
    poso:hasOrientation <me/orientation> .
<me/position> a poso:AbsolutePosition ;
    rdfs:comment "Absolute position of Maxim Van de Wynckel"@en ;
    poso:hasAccuracy <me/position/accuracy> .
<me/position/accuracy> a ssns:Accuracy ;
    schema:maxValue "2.0"^^xsd:float ; schema:unitCode unit:M .
    
<me/orientation> a poso:Orientation ;
    rdfs:comment: "Orientation of Maxim Van de Wynckel"@en ;
    poso:hasAccuracy <me/orientation/accuracy> .
<me/orientation/accuracy> a ssns:Accuracy ;
    schema:maxValue "15.0"^^xsd:float ; schema:unitCode unit:Deg .

Usage

Observation

turtle
<position/1654350300000> a sosa:Observation ;
    sosa:hasFeatureOfInterest <me> ;
    sosa:observedProperty  <me/position> ;
    sosa:resultTime "2022-06-04T15:55:00+02:00"^^xsd:dateTimeStamp ;
    poso:usedSystem <system/OPS> ;
    sosa:hasResult [ a geosparql:Geometry ;
        geosparql:hasSpatialAccuracy [ a qudt:QuantityValue ;
            qudt:unit unit:CentiM ; qudt:numericValue "28"^^xsd:float ] ;
        geosparql:asWKT """
            <http://www.opengis.net/def/crs/OGC/1.3/CRS84>
            Point(4.888028 50.31397)"""^^geosparql:wktLiteral ;
        geosparql:dimension 2 ] .

Usage

Observation ...

turtle
<position/1647513000000> a sosa:Observation ;
    sosa:hasFeatureOfInterest <me> ;
    sosa:observedProperty  <me/position> ;
    sosa:resultTime "2022-03-17T11:30:00+01:00"^^xsd:dateTimeStamp ;
    sosa:usedProcedure posoc:KNNFingerprinting ;
    poso:usedSystem <system/IPS> ;
    sosa:hasResult [ a poso:AbsolutePosition ;
        poso:inDeployment <deployment/building_a> ;
        poso:hasAccuracy [ a ssns:Accuracy ;
            schema:maxValue "25.0"^^xsd:float ; 
            schema:unitCode unit:CentiM ] ;
        poso:xAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "5"^^xsd:double ] ;
        poso:yAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "6"^^xsd:double ] ;
        poso:zAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "3.5"^^xsd:double ] ] .

Usage

Observation ...

turtle
<position/1647513000000> a sosa:Observation ;
    sosa:hasFeatureOfInterest <me> ;
    sosa:observedProperty  <me/position> ;
    sosa:resultTime "2022-03-17T11:30:00+01:00"^^xsd:dateTimeStamp ;
    sosa:usedProcedure posoc:KNNFingerprinting ;
    poso:usedSystem <system/IPS> ;
    sosa:hasResult [ a poso:AbsolutePosition ;
        poso:inDeployment <deployment/building_a> ;
        poso:hasAccuracy [ a ssns:Accuracy ;
            schema:maxValue "25.0"^^xsd:float ; 
            schema:unitCode unit:CentiM ] ;
        poso:xAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "5"^^xsd:double ] ;
        poso:yAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "6"^^xsd:double ] ;
        poso:zAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "3.5"^^xsd:double ] ] .

Usage

Observation ...

turtle
<position/1647513000000> a sosa:Observation ;
    sosa:hasFeatureOfInterest <me> ;
    sosa:observedProperty  <me/position> ;
    sosa:resultTime "2022-03-17T11:30:00+01:00"^^xsd:dateTimeStamp ;
    sosa:usedProcedure posoc:KNNFingerprinting ;
    poso:usedSystem <system/IPS> ;
    sosa:hasResult [ a poso:AbsolutePosition ;
        poso:inDeployment <deployment/building_a> ;
        poso:hasAccuracy [ a ssns:Accuracy ;
            schema:maxValue "25.0"^^xsd:float ; 
            schema:unitCode unit:CentiM ] ;
        poso:xAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "5"^^xsd:double ] ;
        poso:yAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "6"^^xsd:double ] ;
        poso:zAxisValue [ a qudt:QuantityValue ;
            qudt:unit unit:M ; qudt:numericValue "3.5"^^xsd:double ] ] .

Usage

Relative Position

turtle
<landmark/wap_1> a poso:Landmark ;
    rdfs:label "Wireless Access Point 1"@en ;
    poso:hasPosition [ a poso:AbsolutePosition ;
        poso:hasAccuracy [ ... ] ;
        poso:xAxisValue [ ... ] ; poso:yAxisValue [ ... ] ; poso:zAxisValue [ ... ] ] .
<me/position/relative/wap_1> a poso:RelativeDistance ;
    ssn:isPropertyOf <me> ; # Relative distance from <me> ...
    poso:isRelativeTo <landmark/wap_1> ; # to <landmark/wap_1>
    rdfs:comment "Relative position of Maxim Van de Wynckel to WAP_1"@en .
<position/relative/wap_1/1646891100000> a sosa:Observation ;
    sosa:hasFeatureOfInterest <me>, <landmark/wap_1> ;
    sosa:observedProperty  <me/position/relative/wap_1> ;
    sosa:resultTime "2022-03-10T06:45:00+01:00"^^xsd:dateTimeStamp ;
    poso:madeBySystem <system/IPS> ;
    sosa:usedProcedure posoc:LDPL ; # Log-distance path loss
    sosa:hasResult [ a qudt:QuantityValue ;
        qudt:unit unit:Meter ; qudt:value "3.7"^^xsd:double ] ;
    sosa:hasResult [ a qudt:QuantityValue ;
        qudt:unit unit:DeciB_M ; qudt:value "-82"^^xsd:integer ] .

Usage

Relative Position

turtle
<landmark/wap_1> a poso:Landmark ;
    rdfs:label "Wireless Access Point 1"@en ;
    poso:hasPosition [ a poso:AbsolutePosition ;
        poso:hasAccuracy [ ... ] ;
        poso:xAxisValue [ ... ] ; poso:yAxisValue [ ... ] ; poso:zAxisValue [ ... ] ] .
<me/position/relative/wap_1> a poso:RelativeDistance ;
    ssn:isPropertyOf <me> ; # Relative distance from <me> ...
    poso:isRelativeTo <landmark/wap_1> ; # to <landmark/wap_1>
    rdfs:comment "Relative position of Maxim Van de Wynckel to WAP_1"@en .
<position/relative/wap_1/1646891100000> a sosa:Observation ;
    sosa:hasFeatureOfInterest <me>, <landmark/wap_1> ;
    sosa:observedProperty  <me/position/relative/wap_1> ;
    sosa:resultTime "2022-03-10T06:45:00+01:00"^^xsd:dateTimeStamp ;
    poso:madeBySystem <system/IPS> ;
    sosa:usedProcedure posoc:LDPL ; # Log-distance path loss
    sosa:hasResult [ a qudt:QuantityValue ;
        qudt:unit unit:Meter ; qudt:value "3.7"^^xsd:double ] ;
    sosa:hasResult [ a qudt:QuantityValue ;
        qudt:unit unit:DeciB_M ; qudt:value "-82"^^xsd:integer ] .

Usage

Relative Position

turtle
<landmark/wap_1> a poso:Landmark ;
    rdfs:label "Wireless Access Point 1"@en ;
    poso:hasPosition [ a poso:AbsolutePosition ;
        poso:hasAccuracy [ ... ] ;
        poso:xAxisValue [ ... ] ; poso:yAxisValue [ ... ] ; poso:zAxisValue [ ... ] ] .
<me/position/relative/wap_1> a poso:RelativeDistance ;
    ssn:isPropertyOf <me> ; # Relative distance from <me> ...
    poso:isRelativeTo <landmark/wap_1> ; # to <landmark/wap_1>
    rdfs:comment "Relative position of Maxim Van de Wynckel to WAP_1"@en .
<position/relative/wap_1/1646891100000> a sosa:Observation ;
    sosa:hasFeatureOfInterest <me>, <landmark/wap_1> ;
    sosa:observedProperty  <me/position/relative/wap_1> ;
    sosa:resultTime "2022-03-10T06:45:00+01:00"^^xsd:dateTimeStamp ;
    poso:madeBySystem <system/IPS> ;
    sosa:usedProcedure posoc:LDPL ; # Log-distance path loss
    sosa:hasResult [ a qudt:QuantityValue ;
        qudt:unit unit:Meter ; qudt:value "3.7"^^xsd:double ] ;
    sosa:hasResult [ a qudt:QuantityValue ;
        qudt:unit unit:DeciB_M ; qudt:value "-82"^^xsd:integer ] .

Usage

Relative Position

turtle
<landmark/wap_1> a poso:Landmark ;
    rdfs:label "Wireless Access Point 1"@en ;
    poso:hasPosition [ a poso:AbsolutePosition ;
        poso:hasAccuracy [ ... ] ;
        poso:xAxisValue [ ... ] ; poso:yAxisValue [ ... ] ; poso:zAxisValue [ ... ] ] .
<me/position/relative/wap_1> a poso:RelativeDistance ;
    ssn:isPropertyOf <me> ; # Relative distance from <me> ...
    poso:isRelativeTo <landmark/wap_1> ; # to <landmark/wap_1>
    rdfs:comment "Relative position of Maxim Van de Wynckel to WAP_1"@en .
<position/relative/wap_1/1646891100000> a sosa:Observation ;
    sosa:hasFeatureOfInterest <me>, <landmark/wap_1> ;
    sosa:observedProperty  <me/position/relative/wap_1> ;
    sosa:resultTime "2022-03-10T06:45:00+01:00"^^xsd:dateTimeStamp ;
    poso:madeBySystem <system/IPS> ;
    sosa:usedProcedure posoc:LDPL ; # Log-distance path loss
    sosa:hasResult [ a qudt:QuantityValue ;
        qudt:unit unit:Meter ; qudt:value "3.7"^^xsd:double ] ;
    sosa:hasResult [ a qudt:QuantityValue ;
        qudt:unit unit:DeciB_M ; qudt:value "-82"^^xsd:integer ] .

Conclusion and Future Work

We presented the new POSO ontology
- Describe positioning systems, their algorithms and technologies
- Describe observations and the type of observation
Additional poso-common module for common algorithms and systems
Interoperability between positioning systems
Future allignment modules for sensors and specific algorithms

In this paper we presented our Positioning System Ontology named POSO. This is a new ontology that allows you to describe positioning systems and their implemented algorithms as well as the data they produce. We included the poso common module that will also be expanded in the future with more algorithms, frameworks and in use systems. We hope that POSO will help in creating interoperable positioning and navigation applications. Which could allow us to transition to a single interoperable application to navigate both outdoors, indoor or underground. Future work will definitely be done on additional allignment modules where we link POSO to other ontologies that already describe different types of sensors that are commonly used in these types of systems. Thank you for your attention.