Uncertainty of measurement for a given pollutant

Compute measurement uncertainty for time series of a given pollutant.

Usage

unc_year(obs, alpha = 0.2, RV = 200, U_RV = 0.24, Np = 5.2, Nnp = 5.5, ...)

Arguments

obs

A numeric vector, data.frame or data.table of observed concentration data.

alpha

Non-proportional fraction factor (0 <= a <= 1). Default value = 0.20 (for NO_2).

RV

Reference value. Default value = 200 (for NO_2).

U_RV

Standard measurement uncertainty around the RV. Default value = 0.24 (for NO_2).

Np

Parameter to account for the compensation of errors. Default value = 5.2 (for NO_2).

Nnp

Parameter to account for the compensation of errors. Default value = 5.5 (for NO_2).

...

Optional parameters passed to mean, such as na.rm = TRUE.

Details

The function computes the 95th percentile uncertainty for yearly averaged measurement, as described in Annex 1 of Janssen et al., FAIRMODE Guidance Document on Modelling Quality Objectives and Benchmarking (Fairmode MQO Guidance V3.2): $$ U(\bar{O}) \approx U_r(RV) \sqrt{\frac{1 - \alpha^2}{N_p} \bar{O}^2 + \frac{\alpha^2 \cdot RV^2}{N_{np}}} $$

The values of the parameters for various pollutants are reported in Table 6 of the Fairmode MQO Guidance.