The problem of mixed sampling frequencies is exemplified in Figures 1 and 2.
One solution to the problem of mixed sampling frequencies is to convert higher-frequency data to match the sampling rate of the lower-frequency data.
"Regression Models with Mixed Sampling Frequencies." Journal of Econometrics, October 2010b, 158(2), pp.
2.1.4 Describe the mixed sampling
scheme (i.e., concurrent-identical, concurrent-parallel, concurrent-nested, concurrent-multilevel, sequential-identical, sequential-parallel, sequential-nested, and sequential-multilevel).