Noise level observed
Description
It represents an observation of those acoustic parameters that estimate noise pressure levels at a certain place and time. This entity is primarily associated with the Smart City and environment vertical segments and related IoT applications.
Data Model
-
id
: Unique identifier. -
type
: Entity type. It must be equal toNoiseLevelObserved
. -
dateCreated
: Entity's creation timestamp.- Attribute type: DateTime
- Optional
-
dateModified
: Last update timestamp of this entity.- Attribute type: DateTime
- Optional
-
location
: Location of this observation represented by a GeoJSON geometry.- Attribute type:
geo:json
. - Normative References: https://tools.ietf.org/html/rfc7946
- Mandatory if
address
is not present.
- Attribute type:
-
address
: Civic address of this observation.- Normative References: https://schema.org/address
- Mandatory if
location
is not present.
-
name
: Name given to this observation.- Normative References: [https://schema.org/name]
- Optional
-
description
: Description given to this observation.- Normative References: [https://schema.org/description]
- Optional
-
dateObserved
: The date and time of this observation in ISO8601 UTC format. It can be represented by an specific time instant or by an ISO8601 interval. As a workaround for the lack of support of Orion Context Broker for datetime intervals, it can be used two separate attributes:dateObservedFrom
,dateObservedTo
. -
dateObservedFrom
: Observation period start date and time. SeedateObserved
.- Attribute type: DateTime.
- Optional
-
dateObservedTo
: Observation period end date and time. SeedateObserved
.- Attribute type: DateTime.
- Optional
-
refDevice
: A reference to the device which captured this observation.- Attribute type: Reference to an entity of type
Device
- Optional
- Attribute type: Reference to an entity of type
-
sonometerClass
: Class of sonometer (0, 1, 2) according to ANSI used for taking this observation. This attribute is useful when no device entity is associated to observations. It allows to convey, roughly, information about the precision of the measurements.- Attribute type: Text
- Allowed values: one of (
"0"
,"1"
,"2"
) - Optional
Representing acoustic parameters
The number of acoustic parameters measured can vary. As a result this model prescribes the following attributes to convey the referred parameters:
-
measurand
: An array of strings containing details (see format below) about each acoustic parameter observed.- Attribute type: List of Text.
- Allowed values: Each element of the array must be a string with the following format
(a list of values separated by the
|
character):<measurand>| <observedValue>| <description>
, where:measurand
: corresponds to a term defined at http://www.acoustic-glossary.co.uk/definitions-l.htm.observedValue
: corresponds to the value for the measurand as a number expressed in decibels.description
: short description of the measurand.- Examples:
"LAeq | 93.6 | A-weighted, equivalent, sound level" "LAS | 91.6 | A-weighted, Slow, sound level" "LAeq,d | 65.4 | A-weighted, equivalent, day period, sound level"
- Mandatory
-
In order to enable a proper management of the historical evolution of the different acoustic parameters, for each element described by the
measurand
array list there MAY be an attribute which name MUST be exactly equal to the measurand name described on themeasurand
array. The structure of such an attribute will be as follows:- Attribute name: Equal to the name of the measurand, for instance
LAeq
. - Attribute type: Number
- Attribute value: Exactly equal (same unit of measurement) to the value provided in the
measurand
array.
- Attribute name: Equal to the name of the measurand, for instance
Representing weather conditions
There are two options for representing them:
- A/ Through a linked entity of type
WeatherObserved
(attribute namedrefWeatherObserved
) which will capture the associated weather conditions. - B/ Adding weather-related properties defined at WeatherObserved.
Examples of use
{
"id": "Vitoria-NoiseLevelObserved-2016-12-28T11:00:00_2016-12-28T12:00:00",
"type": "NoiseLevelObserved",
"location": {
"type": "Point",
"coordinates": [-2.6980, 42.8491]
},
"dateObserved": "2016-12-28T11:00:00/2016-12-28T12:00:00",
"measurand": [
"LAeq | 67.8 | A-weighted, equivalent, sound level",
"LAmax | 94.5 | A-weighted, maximum, sound level",
],
"LAeq": 67.8,
"LAmax": 94.5,
"sonometerClass": "2"
}
Open Issues
Standard dictionary for acoustic parameters.