Combining multiple time-based datasources with different periods
(not enough rep for comment)
Can you tell us more about the data streams? I am a roboticist, and I often deal with sensors which are outputting data streams at different rates. Specifically, can you please elaborate on the following:


do the data streams have the same modality? (eg, are they all telling you the velocity of something, or is one telling you velocity and the other position, leaving you to infer velocity?)
is either stream noisy and/or can you otherwise get conflicting data from the streams? If so, do you have an error model?


Once I know more about your streams, I will try to suggest some relevant literature.