AQD - Primary Observations Time
primaryObservation
day
Daily average/mean
The daily average or daily mean derived from a sample period of one day.
dc
Data Capture
The data capture associated with a primary observation. This primary observation parameter is the percentage of the time envelope defined by its start and end time for which a sample or observation has been made or taken. It is essential for sampler based measurements where (i) random measurements operate over the time envelope defined, (ii) where samples are frequently not taken for the complete sampling envelope and (ii) for samples bulked for analysis. In these cases time weight concentrations estimates are calculated using the value domain of the "dc" field.
For automatic measurements the value will frequently not be stored in local systems as hourly means derived from <75% dc are discarded. At best the dc rate will be known to >=75% (as a valid hourly mean for example). For automatic measurements return -99 or -999 for the value domain of the "dc" field.
fortnight
Fortnightly average/mean
The average or mean derived from a sample over the period of 2-weeks. The duration will be defined by the startTime & endTime components of the data array.
hour
Hourly average/mean
The hourly average or hour mean is the average of all valid minute values for an hour. An hourly average is calculated if at least 45 valid minutes values are available.
month
Monthly average/mean
The monthly average or mean derived from a sample period of one month.
n-hour
n hourly average/mean
The n-hourly average or n-hour mean is the average of all valid minute values for n-hour. An n-hourly average is calculated if at least 75% are available.
Note: n must be equal to 2, 3, 4, 6 in order to be able to correctly aggregate the data.
quarter
Quarterly average/mean
The average or mean derived from a sample(s) taken over a 3-month period. The duration will be defined by the startTime & endTime components of the data array.
var
Variable sample
The average or mean derived from a sample of variable temporal duration. The duration will be defined by the startTime & endTime components of the data array.
week
Weekly average/mean
The weekly average or mean derived from a sample period of one week.
year
Yearly average/mean
The yearly average or mean derived from a sample period of one year - PRIMARY DATA