Synchronize callbacks of multiple subscribers in order of timestamps

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Hi,

I was wondering whether there is existing support for synchronizing the callbacks of multiple subscribers based on the order of the timestamps.

For instance, I have one sensor source running measuring at 200 Hz, and another at 20 Hz. Currently the timestamps of the 20 Hz source are ~0.1 seconds later than the 200 Hz source without any message filtering.

I've looked at http://wiki.ros.org/message_filters , and TimeSynchronizer provides close to what I'm looking for. However, it appears that if I was to use this, I would drop 90% of the faster sensor measurements, as the callback would not be executed until the 20 Hz source has a measurement.

Am I understanding this correctly, and are there any existing solutions?

Thanks.