Comparison Public Lighting vs Irrigation in Green Areas
The next table compares aspects of the two use cases for the first challenge.
The objective is to find a common way to analyze this kind of work and get a common set of attributes describing the specification.
This is just a first proposal, prior to the participation of experts in this field.
Comparison Table
| Comparison Aspect | Public Lighting | Irrigation in Green Areas |
|---|---|---|
| Ideal final objective | Street surface (roadway/sidewalk defined) with a minimum lux level that meets or exceeds the reference parameter for the service; ideally, lux measured directly at roadway points (observed service outcome). | Soil/vegetation target zone with effective irrigation in the root volume, equivalent to at least the defined daily/weekly threshold; ideally, moisture at roots or water in soil measured directly in the useful volume. |
| Context information | Ambient luminosity below which those lux must be guaranteed; street geometry, orientation, shadows, and weather help adjust when and how much to turn on/dim. If lux is measured at the roadway, context only modifies default actions or covers exceptional situations. | Environmental and weather conditions (temperature, evapotranspiration, expected rain, wind, soil and vegetation type) that determine the need to irrigate or adjust volume. If moisture at roots or useful water is measured directly, context fine-tunes scheduling or manages exceptions and forecasts. |
| Main physical magnitude | Lux on the street surface as the direct representation of the illumination level perceived by people; lumens emitted and watts consumed describe the luminaire's behavior and energy cost, but don't replace lux as the outcome. | Water available in the root system: volumetric soil moisture in the root volume or water accumulated in that volume; flow rate, pressure, and time describe system operation, but the outcome is useful water at roots. |
| Direct vs. induced measurement | - Direct: lux measured at roadway points; watts, voltage, active/reactive power, and status/dimming measured at luminaire or line. - Induced: lux and lumens on surface calculated from electrical energy consumed, lamp characteristics (photometric curves, temperature, degradation/wear), and installation (height, orientation, distribution). | Direct: water volume measured with meter at the appropriate point or soil moisture at roots. - Induced: volume calculated from valve open time and pressure, applying flow curves; with the reach surface and system (spray, drip, etc.), the water effectively reaching its destination in the root volume is estimated. |
| Level at which it's observed | Individual light point (luminaire), street segment, line/circuit, cabinet, or aggregated zone; the perceived service is typically evaluated at segment/zone level even though many measurements are taken at the luminaire or electrical head. | Application point (sprayer/drippers), irrigation sector, planting zone, or complete green area; the useful outcome is evaluated in the root volume of an area/zone, even though operational observation happens at valves, meters, or sectors. |
| Typical available raw data | Electrical measurements (watts, voltage, active/reactive power, current, frequency), statuses (ON/OFF, dimming level, alarms/failures), timestamps, luminaire/cabinet/line identifiers, possible lux at some points, plus installation metadata (height, orientations, optical type, nominal power). | Water meter readings (volume or flow rate), valve statuses and open time, line pressure, soil moisture at some points, temperature, measured or expected rain, sector/valve/zone identifiers, plus system metadata (irrigation type, nominal flow rates, served surface). |
| Minimum metadata for comparability | Value type (measured, estimated, predicted, synthetic), unit (lux, W, V, VAR…), temporal interval (timestamp, start/end, resolution), spatial scope (luminaire, segment, line, cabinet, zone), acquisition method (direct sensor, photometric calculation, energy distribution), operating conditions (dimming status, control mode), and data quality (accuracy, completeness, availability, consistency). | Value type (measured, estimated, predicted, synthetic), unit (liters, m³, % moisture…), temporal interval (moment, period, resolution), spatial scope (irrigation point, sector, planting zone), acquisition method (direct meter, time×pressure calculation, distribution model in spray/drip), environmental conditions (rain, temperature, wind, soil and crop type), and data quality (accuracy, completeness, availability, consistency). |
| Typical KPI examples | - Average lux per street segment; percentage of measurement points below a lux threshold - kWh per km of street or per zone in a period; service hours by dimming level - Failure rate per segment or per luminaire - Energy cost per unit of illuminated surface | Liters per m² and day/week; percentage of irrigations aligned with weather forecast or with a water need curve Water consumption per zone and period; percentage of moisture readings in optimal range Ratio between water delivered and water estimated useful at roots Availability/completeness of irrigation data in each zone. |
| Mapping to Smart Data Models | Streetlight / StreetlightControlCabinet and NGSI-BD models for lighting: properties like powerConsumption, maxPowerConsumption, minPowerConsumption, luminousFlux, mode, status, location, and extensions for illuminance (lux at roadway) as service observation. | Irrigation entities in environment/water/green areas models (e.g., IrrigationSystem, WaterConsumption, SoilMoisture per water/environment profiles), with properties like flow, volume, valveStatus, pressure, soilMoisture, irrigationWater, areaServed, location, and quality and measurement method attributes. |
| Mapping to SAREF / SAREF4CITY / SAREF4AGRI | saref:Device / s4city:PublicLightingDevice for luminaires and cabinets; observations modeled with saref:Measurement that saref:relatesToProperty to properties like s4envi:Illuminance (lux), saref:Power, saref:Energy, with saref:hasTime, saref:hasUnitOfMeasure, saref:hasLocation and method/quality annotations. | saref:Sensor, saref:Actuator and agricultural resources in SAREF4AGRI: s4agri:SoilMoisture, s4agri:IrrigationWater, s4agri:SoilTemperature, s4agri:AirTemperature, s4agri:AmbientHumidity, s4agri:Precipitation, linked via saref:Measurement with units, time, location, and metadata; valves and meters as devices acting/observing on those properties. |
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