This document summarizes Just van den Broecke's presentation on open sensor networks. It discusses (1) the Smart Emission Nijmegen project from 2015-2017 where citizens measured air quality and noise using low-cost sensors to build an open sensor platform. It then (2) describes the Smart Emission platform resulting from the project which integrates sensor data using open standards and APIs. Finally, it (3) provides an example of bridging IoT sensors to the platform using the SensorThings API to map sensor data from The Things Network to the API in real-time.

1. Open Sensor
Networks
Just van den Broecke
Just Objects B.V.
https://justobjects.nl
https://twitter.com/justb4
IoT SenseMakers Ams Meetup
Amsterdam - 18 sept, 2019
Met dank aan

2. ABOUT
Independent Open
Source Geospatial
Professional
justobjects.nl
Member of the
OpenGeoGroep (NL)
www.opengeogroep.nl
Chair
OSGeo.nl
1. Intro

3. Air Quality Sensor Projects
• 2014/2015 - SOSPilot - Geonovum en RIVM
RIVM LML Data via OGC Sensor Observation Service (SOS)
http://sensors.geonovum.nl
• 2015-2017 - Smart Emission Nijmegen - Consortium
Burgers meten zelf luchtkwaliteit en geluid, building the SE Platform
http://smartemission.ruhosting.nl
• 2017-2018 - Smart Emission - Consolidation en Scaling
Smart City Living Lab (multiple cities),
Green Challenge Nijmegen, AirSensEUR (EU JRC)
Luftdaten.info Integration
SE Platform Migration to PDOK - Kadaster
https://data.smartemission.nl
• 2018- AirSensEUR - Open HW Sensor Box - European Commission JRC
deploy 5 AirSensEUR Boxes, connect to Smart Emission Platform
https://justobjects.nl/emit-5

4. Smart Emission
Nijmegen Project
Participants
http://smartemission.ruhosting.nl/

5. Inclusive Citizen Sensing
▪ Citizen-sensor-networks for fine-grained
measurements, with new low-cost sensing devices
▪ Transparency and democracy of pollution
monitoring, ‘making the externalities (e.g. noise, air
pollution) visible’
▪ Cost-effective environmental monitoring with
Open Source, Open Data, Open Standards (APIs)
Smart Emission Nijmegen

6. Which type of low cost sensors to deploy?
Quality and Price
Number of sensors applied in a city
Smart Emission
“Jose”
Aireas
“Airbox”
“Smart Citizen Kit”
RIVM National
AQ Stations
Smart Emission Nijmegen

7. Smart Emission Nijmegen

8. Smart Emission
Platform
Resulting from the
Smart Emission Nijmegen project
and subsequent integration into the
Dutch Kadaster PDOK Kubernetes Cloud

9. Smart Emission
Platform
WMS WFS SOS STA
Client
Apps/Viewers
web-APIs
sensors
Collector APIs
SE Platform - The Big Picture
Dataflow
luftdaten.info

10. luftdaten.info
Smart
Emission
Platform
WMS WFS SOS STA
Intemo Data
Collector
InfluxDB Data
Collector
RIVM LML
SOSInfluxDB
HTTP
Luftdaten
API
Harvesters
ETL
LML
Influx
HTTP
Sensors
API
API
Outbound
Inbound
Dataflow
SE Platform - Dataflow and APIs
Whale
API
Decoupling
Push/Pull:
Data Collectors
+Harvesters
MQTT

11. Viewers talk to (OGC) APIs
https://data.smartemission.nl (data platform)
Heron
Viewer
Smart
App
52North
SOS Viewer
Grafana
Extern

12. Viewers
https://data.smartemission.nl/waalkade/
Example
Viewer

13. Thoughts

14. All Data
is
Spatio-Temporal
Spatial Temporal
Geo IoT

16. http://cameronshorter.blogspot.com/2019/08/

17. All Data
is
Spatio-Temporal
Spatial Temporal
Geo IoT

18. Internet
of
Silos
Convenience
over
Freedom

20. Open APIs & Tech
for Spatio-temporal
to the Rescue?

21. Spatio-temporal DB:
PostgreSQL with
PostGIS+TimescaleDB
OGC SensorThings
API
Other Talk

22. OGC SensorThings API
Showcase Modern Standard
(REST) API-based: HTTP Verbs
Data Model is First Class Citizen
Multiple FOSS Implementations
Linked Data, Paging, OData
Pub/Sub via MQTT
GOST
SOS-Killer?
(Geo)JSON Encoding

23. SensorThings API - Model

24. http://ogc-iot.github.io/ogc-iot-api/datamodel.html

25. STA Entity Real World Entity Instance
Thing Thermostaat Honeywell Lyric T6 #234
Location Locatie Thermostaat Building 9, Kamer 14
Sensor Temperatuur Sensor DHT11 #12
ObservedProperty Temperatuur Graden Celsius
Observation Waarde + Tijd 21C op 2018-12-11T18:09:05
Datastream (Verbindt T, S, OP en O)
FeatureOfInterest Kamer Building 9, Kamer 14
SensorThings API - Not just Sensor Devices

26. SensorThings API - Example SE Entity Mapping

27. STA Entity Real World Entity Instance
Thing Vogelhut Natuurmon. Vogelhut #234
Location Plaats Vogelhut Mosselseweg 64, 1245AF Otterlo
Sensor Verrekijker Swarovski Swarovision 1900 10x40
ObservedProperty Diersoort Vogels
Observation Aantal + Tijd 1 op 2018-12-11T18:09:05
Datastream (Verbindt T, S, OP en O)
FeatureOfInterest Soort en Locatie Vogel Merel op 4.9344, 52.567
SensorThings API - Example Mapping

28. Geodan GOST - Open Source STA in GoLang
https://github.com/gost

29. https://data.smartemission.nl/data

30. https://api-samenmeten.rivm.nl/v1.0/
RIVM SensorThings API

33. IoT Platform met STA
SensorThings
API
Server
API
Dataflow
MQTT
STA
Dashboards/
Viewers
Sensors

34. Fun PoC
Bridging IoT with Geo:
TheThingsNetwork to
SensorThings API

35. Demo Setup
GOST
API
Dataflow
GOST
Dashboard
Node-Red
ThingsNode
MQTT MQTT
STA
Process
MQTTBridge
ttn2sta
PySense +
LoPy
Docker
Postman
ProvisioningAny LoRa/TTN Device
Docker Containers

36. Steps
• Install ThingsNode as TTN App and Device as usual
• Test MQTT uplink:
$ mosquitto_sub -h eu.thethings.network -t ‘+/devices/+/ up'-u
'mythingsnode1' -P ‘ttn-account-v2.*****’ -v
• Install SensorThings Geodan GOST Stack
$ wget https://raw.githubusercontent.com/gost/
docker-compose/master/docker-compose.yml
$ docker-compose up
• Postman: provision STA Entities, Examples:
https://github.com/gost/workshops/tree/master/
2017_foss4g_boston
• Node-Red (or regular Python): develop MQTT Bridge
MQTT from TTN:
https://www.thethingsnetwork.org/docs/applications/mqtt/
MQTT to STA: see “GOST FOSS4G Boston” workshop above
ttn2sta: copy TTN Payload data to STA result and
result- and/or phenomenonTime

37. TTN to STA Mapping

38. All the Code needed!

39. STA Observations

40. ▪ All Entities (root)
http://localhost:8080/v1.0
▪ All Observations from all Things (paged)
http://localhost:8080/v1.0/Observations
▪ All Observations Thing with id=3
http://localhost:8080/v1.0/Things(3)?$expand=Datastreams/Observations
▪ Last Observation Thing(3)
http://localhost:8080/v1.0/Things(3)?$expand=Datastreams/Observations($top=1)
▪ All Observations after Dec 11, 2018 20:57 UTC
http://localhost:8080/v1.0/Observations?$filter=resultTime%20gt
%20%272018-12-11T20:57:00.000Z%27
▪ Etc, more examples:
https://smartplatform.readthedocs.io/en/latest/cookbook.html
STA REST/OData Queries

41. Links
https://data.smartemission.nl (data platform)
https://github.com/smartemission (source code)
https://smartplatform.readthedocs.io (documentation)
https://smartplatform.readthedocs.io/en/latest/evolution.html (SensorSDI)
https://geoforum.nl/c/datasets/sensordata (support and comms)
https://en.wikipedia.org/wiki/SensorThings_API (SensorThings API, STA)
https://www.gostserver.xyz/ (Geodan STA Open Source Implementation)
https://justobjects.nl/category/smartemission/ (Just’s Blog on sensor stuff)
https://airsenseur.org/ (EU AirSensEUR)
https://www.geonovum.nl/over-geonovum/actueel/doe-mee-met-de-
hackaton-sensorthings-api-eind-oktober (STA Hackathon)
We would like to acknowledge for their valuable input:
All partners of the Smart Emission Consortium
Thank You!
https://www.slideshare.net/justb4/open-sensor-networks
This Presentation: