gps_timestamp GPS Timestamp in UTC
latitude      GPS position
longitude     GPS position
NO_ppb        NO concentration in parts per billion
NO2_ppb       NO2 concentration in parts per billion
O3_ppb        O3 concentration in parts per billion
CO_ppm        CO concentration in parts per million
CO2_ppm       CO2 concentration in parts per million
PMch1_perL    PM channel 1 measurement in counts per litre
PMch2_perL    PM channel 2 measurement in counts per litre
PMch3_perL    PM channel 3 measurement in counts per litre
PMch4_perL    PM channel 4 measurement in counts per litre
PMch5_perL    PM channel 5 measurement in counts per litre
PMch6_perL    PM channel 6 measurement in counts per litre
PM25_ugm3     PM2.5 concentration in µg/m3