Noise Level Observed
This repository is now archived and subsequent works will be carried out the in Smart data models repositories.
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. In addition it also represents a break down of the frequencies present in the sound in accordance with the ISO 3741:2010 standard frequencies of 100 Hz to 10 000 Hz one-third octave band.
Data Model
The data model is defined as shown below:
-
id
: Unique identifier. -
type
: Entity type. It must be equal toNoiseLevelObserved
. -
source
: A sequence of characters giving the source of the entity data. -
dataProvider
: Specifies the URL to information about the provider of this information- Attribute type: Property. URL
- Optional
-
dateCreated
: Entity's creation timestamp.- Attribute type: Property. DateTime
- Read-Only. Automatically generated.
-
dateModified
: Last update timestamp of this entity.- Attribute type: Property. DateTime
- Read-Only. Automatically generated.
-
location
: Location of this observation represented by a GeoJSON geometry.- Attribute type: GeoProperty.
geo:json
. - Normative References: https://tools.ietf.org/html/rfc7946
- Mandatory if
address
is not present.
- Attribute type: GeoProperty.
-
address
: Civic address of this observation.- Normative References: https://schema.org/address
- Mandatory if
location
is not present.
-
name
: Name given to this observation. -
description
: Description given to this observation.- Normative References: https://schema.org/description
- Optional
-
dateObserved
: The date and time of this observation represented 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
.- Attribute type: Property. ISO8601 interval represented as Text.
- Optional
-
dateObservedFrom
: Observation period start date and time. SeedateObserved
.- Attribute type: Property. DateTime.
- Mandatory
-
dateObservedTo
: Observation period end date and time. SeedateObserved
.- Attribute type: Property. DateTime.
- Mandatory
-
refDevice
: A reference to the device which captured this observation.- Attribute type: Relationship. Reference to an entity of type
Device
- Optional
- Attribute type: Relationship. 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: Property. Text
- Allowed values: one of (
"0"
,"1"
,"2"
) - Optional
-
frequencies
: Specifies the frequencies collected from the sensor represented by the ISO 3741:2010 standard frequencies of 100 Hz to 10 000 Hz one-third octave band. The value of each frequency is the A-weighted decibel value recorded.Attribute type
: A StructuredObject of frequency : value pairs as defined by the ISO 3741:2010 standard where the values are represented as Numbers- Mandatory
-
refPointOfInterest
: A reference to a point of interest associated to this observation.- Attribute type: Relationship. Reference to an entity of type
PointOfInterest
- Optional
- Attribute type: Relationship. Reference to an entity of type
Representing acoustic parameters
The number of acoustic parameters measured can vary. For each acoustic measurand there MUST be an attribute which name MUST be exactly equal to the acoustic measurand name, as follows:
- Attribute name: Equal to the name of the measurand, for instance
LAeq
,LAmax
. It must correspond to a term defined at http://www.acoustic-glossary.co.uk/definitions-l.htm, with the only exception that those measurands which name contains a,
char, such char shall be substituted by the_
char. For instance, the measurand "LAeq,d" shall be represented by an Attribute which name shall beLAeq_d
. - Attribute type: Property. Number
- Attribute value: corresponds to the value for the measurand as a number expressed in decibels.
- Attribute Metadata:
description
: short description of the measurand. (optional)- Normative References: https://schema.org/description
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.
Representing Frequency Data
As the number of frequencies collected may vary from the ISO standard it is suggested that anything outside of this range be omitted and if frequencies within this range are missing the values are set to 0
Note: JSON Schemas are intended to capture the data type and associated constraints of the different Attributes, regardless their final representation format in NGSI(v2, LD).
Examples
Normalized Example
Normalized NGSI Response
{
"id": "Vitoria-NoiseLevelObserved-2016-12-28T11:00:00_2016-12-28T12:00:00",
"type": "NoiseLevelObserved",
"location": {
"type": "geo:json",
"value": {
"type": "Point",
"coordinates": [-2.698, 42.8491]
}
},
"dateObservedFrom": {
"type": "DateTime",
"value": "2016-12-28T11:00:00"
},
"dateObservedTo": {
"type": "DateTime",
"value": "2016-12-28T12:00:00"
},
"LAeq": {
"value": 67.8,
"metadata": {
"description": {
"value": "A-weighted, equivalent, sound level"
}
}
},
"LAmax": {
"value": 94.5,
"metadata": {
"description": {
"value": "A-weighted, maximum, sound level"
}
}
},
"LAS": {
"value": 91.6,
"metadata": {
"description": {
"value": "A-weighted, Slow, sound level"
}
}
},
"LAeq_d": {
"value": 65.4,
"metadata": {
"description": {
"value": "A-weighted, equivalent, day period, sound level"
}
}
},
"frequencies": {
"value": {
"100": 40,
"125": 40,
"160": 40,
"200": 40,
"250": 40,
"315": 40,
"400": 40,
"500": 40,
"630": 40,
"800": 40,
"1000": 40,
"1250": 40,
"1600": 40,
"2000": 40,
"2500": 40,
"3150": 40,
"4000": 40,
"8000": 40,
"10000": 40
},
"metadata": {
"description": {
"value": "A-weighted, frequency, sound level "
}
}
}
}
key-value pairs Example
Sample uses simplified representation for data consumers ?options=keyValues
{
"id": "Vitoria-NoiseLevelObserved-2016-12-28T11:00:00_2016-12-28T12:00:00",
"type": "NoiseLevelObserved",
"LAS": 91.6,
"LAeq": 67.8,
"LAeq_d": 65.4,
"LAmax": 94.5,
"dateObservedFrom": "2016-12-28T11:00:00.00Z",
"dateObservedTo": "2016-12-28T12:00:00.00Z",
"location": {
"type": "Point",
"coordinates": [-2.698, 42.8491]
},
"frequencies": {
"100": 40,
"125": 40,
"160": 40,
"200": 40,
"250": 40,
"315": 40,
"400": 40,
"500": 40,
"630": 40,
"800": 40,
"1000": 40,
"1250": 40,
"1600": 40,
"2000": 40,
"2500": 40,
"3150": 40,
"4000": 40,
"8000": 40,
"10000": 40
}
}
LD Example
Sample uses the NGSI-LD representation
{
"id": "urn:ngsi-ld:NoiseLevelObserved:Vitoria-NoiseLevelObserved-2016-12-28T11:00:00_2016-12-28T12:00:00",
"type": "NoiseLevelObserved",
"dateObservedFrom": {
"type": "Property",
"value": {
"@type": "DateTime",
"@value": "2016-12-28T11:00:00.00Z"
}
},
"LAmax": {
"type": "Property",
"value": 94.5
},
"LAeq": {
"type": "Property",
"value": 67.8
},
"dateObservedTo": {
"type": "Property",
"value": {
"@type": "DateTime",
"@value": "2016-12-28T12:00:00.00Z"
}
},
"LAeq_d": {
"type": "Property",
"value": 65.4
},
"location": {
"type": "GeoProperty",
"value": {
"type": "Point",
"coordinates": [-2.698, 42.8491]
}
},
"LAS": {
"type": "Property",
"value": 91.6
},
"@context": [
"https://schema.lab.fiware.org/ld/context",
"https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld"
]
}