Internal complexity feature and similarity of the gamma monitoring time series acquired in the environment by two different detection systems

Abstract

The early warning network for continuous monitoring of radiation level in the environment provides the relevant information on the radiation levels in regular conditions and in case of a radiological or nuclear emergency. An automatic gamma radiation monitoring network in Bosnia and Herzegovina consists of two smaller systems based on the MFM-203 and GammaTRACER XL2 monitors. In order to investigate the comparability and reliability of the ambient dose equivalent rate data acquired at all the monitoring stations based on two different detection systems, we have quantified the natural fluctuations and internal features of the investigated time series. It was demonstrated that the data recorded at the GammaTRACER XL2 stations show the larger fluctuations compared to the data collected at the MFM-203 stations in the same period of time. We have applied the DTW measure as an advanced distance measure, and it was observed that two time series show the similarity since the DTW outputs obtained are within the DTW output ranges due to the natural fluctuations that were recorded with the same instrument. The results of the internal complexity feature analysis show that the gamma dose rate time series measured at the GammaTRACER XL2 stations are somewhat less random than the MFM-203 experimental time series. It was observed that there is an overlapping to some extent between the results of complexity dynamics analysis for both time series. The results of the present study show that all the ambient gamma dose rates measured with two different detection systems can be considered comparable and reliable. Such results are of interest for a proper interpretation of the background radiation level data acquired in the environment in regular conditions as well as in accidental situations.