Looking for Data through the API by specifying geographic coordinates and a range

guillaume.slizewicz · January 14, 2020, 1:50pm

Hello Everyone,

I am working on a project of visualisation of air pollution and I would like to retrieve information about air pollution by indicating a geographic position and a range. I know this is doable on other plateform like luftdaten by could not find a way to do it on smartcitizen API. Does this feature exist?

Many thanks,

pral2a · January 14, 2020, 6:34pm

Hi @guillaume.slizewicz

Thanks for posting about your project!

The Smart Citizen API is fully documented here:

https://developer.smartcitizen.me/#summary

The API is quite straightforward to use. For example, you can filter all the active SCK 2.1 in the Barcelona area today like:

https://api.smartcitizen.me/v0/devices?q[kit_id_eq]=26&q[last_reading_at_gt]=2020-01-13T00:00:00Z&near=41.401108,2.215319

We have a full framework for Data Analysis written in Python / Jupyter here:

https://docs.smartcitizen.me/Sensor%20Analysis%20Framework/

We built Python wrapper as part of our API

github.com

fablabbcn/smartcitizen-iscape-data/blob/master/src/data/api_tools.py

import requests
from tzwhere import tzwhere
import pandas as pd
import numpy as np
from datetime import datetime, timedelta

import yaml
from os import getcwd, walk
from os.path import join

from src.data.variables import *
import traceback
from termcolor import colored 

# TODO: Get this automatically
station_kit_ids = (19, 21)
kit_kit_id = 11

# Convertion table from API SC to Pandas
# https://stackoverflow.com/questions/35339139/where-is-the-documentation-on-pandas-freq-tags

This file has been truncated. show original

We also have examples in other languages, like this minimal Processing sketch that retrieves data and sends it over OSC to quickly use it with Max, VVVV, Resolume, etc…

github.com

fablabbcn/smartcitizen-toolkit/blob/master/processing-connectors/SmartCitizenOSC/SmartCitizenOSC.pde

/*

 SmartCitizen API - Procressing.org basic example
 
 This example demonstrate how to do a basic call to the SmartCitizen API 
 to retrieve the latest data from one device and send it over OSC to later 
 use it on OSC compatible tools like: Pure Data, Max MSP, Live, VVVV, Grasshopper...
 
 For more info:
 http://developer.smartcitizen.me/#devices
 
 This code is under public domain.
 
 */

import oscP5.*;
import netP5.*;

OscP5 oscP5;
NetAddress myRemoteLocation;

This file has been truncated. show original

guillaume.slizewicz · January 15, 2020, 9:49am

Hi @pral2a,

Thanks for the swift answer. I am already using the API via device ID and it works like a charm, so first of all thanks for that :).

What I was asking was if you implemented already a filtering function for geographic coordinates, or if it was necessary to parse all devices and then filter them via a script to have only the device within a certain range of a geographic coordinates.

I can see that you can filter for user, id names, and city but cannot see any filter with coordinates.

As an example you will find below the similar URL in luftdaten:

URL= "http://api.luftdaten.info/v1/filter/area=50.867416,4.377298,0.3" # geocoordinates and 300 meters around

I hope this clear things up,
Many thanks,
Guillaume

pral2a · January 15, 2020, 11:54am

Hi,

Sorry, my answer was quite general. I realised your question was way more specific after.

You can filter devices by location and other properties, as I explained in my first answer:

However, it will return you the devices, not the aggregated values.

We don’t provide this feature at the moment as we are against aggregating multiple devices data before a previous analysis of the data as the deployment characteristics and usage can vary from device to device and user to user.

Instead we built a full framework around Python / Jupyter to analyse and process the data.

https://docs.smartcitizen.me/Sensor%20Analysis%20Framework/

@oscgonfer has been leading that task and can give you more information

guillaume.slizewicz · January 15, 2020, 1:49pm

Thanks for the answers. It clears things up :).