I have noticed that the Luftdaten data has been added to the aqicn.org map. The numbers appear different to that on the sensor community site. Does anyone know what algorithms they are applying to the data to get to the numbers they are publishing?
Could you please provide more information on how to get this data on aqicn.org? The “normal” map on their site doesn’t show the data.
On our map we use the average of the last 5 minutes (to minimize the effects of short events with very high or very low values). Maybe they are using only the latest values.
I have noticed that in the U.K. there are small dots on the aqicn map that represent the Luftdaten data. As a for instance ( I hope this link works) Air Pollution in Chilbolton Observatory: Real-time Air Quality Index Visual Map shows the values for the DEFRA Chilbolton site plus smaller dots around some of the local towns and cities e.g. Oxford if you click on the dots it describes the luftdaten sensor.
We have looked into this a bit more and the figures appear to differ as they are reporting the air quality index which doesn’t correspond exactly to the concentration figure measured by the sensors. If anyone doesn’t know this report describes how to calculate it https://www.airnow.gov/sites/default/files/2020-05/aqi-technical-assistance-document-sept2018.pdf
A very quick look at the information suggests that they are using the data directly from the sensor community output but are not using spikes. I am not sure how long they have been adding the data to their map but it would be good if they produced an archive of the information such as they do for the regulated sites.
I would be interested in knowing if they are collaborating in anyway with the sensor community.
There is a air quality index on our site also. This index exists in different versions. Most common is th aqi over the last 24 hours. But this doesn’t really show the actual situation. So a weighted index is used by some sites. This uses hourly average values for the last 24 hours and gives more weight to the last hours (heighest weight for the last hour).
There is an archive of our data at https://archive.sensor.community/ .
Thank you for the information. Yes I had forgotten that the AQI is calculated for PM2.5. So these figures are comparable on both sites. I didn’t realise they were archived so that is useful.
Thank you once again