Analysis of optical atomic clocks readouts aimed on searches for dark-matter signatures

We describe optical atomic clocks readouts' analysis and provide a recipe for analysing data from transcontinental network made of already existing optical atomic clocks to search for dark-matter signatures. We show how to correlate the data and we discuss methods of computing cross-correlation of more than two readouts. Furthermore, we show how to analyse the data from a network of many clocks to exceed previously reported limits on oscillating massive scalar fields couplings to standard matter.