Typical System Extensions

Integrated 32GB SD Card Data Logger

A very low power SD based data logger can be integrated into the system. This allows logging of data exported from 2 of the available serial channels.

Real Time Clock

For systems with no external time source, such as from GPS or other sub system, a battery backed real time clock can be integrated in order to provide date and time.

Remote Mounting of Magnetometer

The magnetometer is normally integrated within the system unit. However, if the system unit is installed in a position with high magnetic anomalies that cannot easily be compensated, for example steel hull, large mooring chains, the magnetometer can be remotely mounted, for example externally at a masthead.

Electronic Compass Input

As an alternative to the magnetometer, an external fluxgate or other compass that supports NMEA HDT and/or HDM messages can be utilised as the source for heading data. As the heading data is integrated with the buoy motion data, updates from the compass would typically need to be 1 second or less.

GPS for Lat/Long Time Data

A GPS unit which can supply GPS data in the form of NMEA GGA or GLL messages can be integrated through one of the serial ports. With the AIM 'passthru' option enabled, any data received from the GPS can be redirected to a downstream system and/or SD card data logger. Also, AIM can also receive NMEA ZDA date and time information which is used to updated the internal clock.

GPS for supplementary Surge/Sway measurement

As outlined in the Spectral Wave Analysis section, directional spectra can be calculated from buoy surge and sway data. This is normally derived from the buoy motions measured by the accelerometer. However, the latitude and longitude data can also be used to supplement the accelerometer data. This is particularly valuable for large buoys with very long period surge and sway properties.