These systems allow data to be collected over multiple tidal cycles and varying wind and
wave conditions. They will also allow data to be collected under high sea state conditions
when manned data collection would not be possible. However current technology is
potentially limited in bandwidth and storage capacity. Autonomous recorder systems are
now available working with bandwidths from a few 10’s Hz to greater than 100 kHz;
however, these systems are often limited by storage capacity, bandwidth and battery life.
For example: at 24 kHz bandwidth, a single channel recorder system will have around 4 days
of continuous record time using 32 GB storage media. By comparison, at a bandwidth of 192
kHz suitable to cover all potential receptor frequencies, the same storage capacity will allow
just over 6 hours continuous recording. An approach used by some autonomous recorders is
the use of a duty-cycled recording schedule. Systems will make timed periodic recordings,
for example 10 minutes every hour at a variety of bandwidths. These capabilities are usually
programmable, allowing extension of the total deployment time within the same bandwidth
total storage limits.