Sensors Description: The ROV Network AHRU is a low cost Auto heading reference unit based on MIMS technology It combines three angular rate gyros with three orthogonal DC accelerometers and three orthogonal magnetometers It also contains a multiplexer, 12 bit A/D converter, and embedded microcontroller, to provide three orientation angles (pitch, roll, yaw) in dynamic and static environments. Operating over the full 360 degrees of angular motion on all three axes, the AHRU provides a serial output of orientation in degrees although other options are available. The digital serial output can also be programmed to provide scaled sensor data from all nine sensors. multiple units can be networked using the built-in RS-485 network protocol. The embedded microcontroller on each node relieves the host system from the burden of orientation calculations, allowing deployment of dozens of 3DM-G® nodes with no significant decrease in system throughput. Output modes and software filter parameters are user programmable. All programmed parameters and calibration data are stored in nonvolatile memory. The device is perfect for any size of ROV or Autonomous vehcile. With is tiny size and low mass, it is even perfect for airbourne systems.

Orientation Range	360 degrees full scale (FS), all axes (Matrix, Quaternion modes)
Angular Velocity Range	+/-300 degrees/second (max.)
A/D Resolution	12 bits
Dynamic Compensation	closed loop digital control (0 to 50 Hz)
Orientation Angle Resolution	< 0.1 degrees
Temperature Drift	+/- 0.025%/degrees C
Nonlinearity	0.23% full scale (tested in static conditions)
Repeatability	0.10 degrees
Accuracy	+/-5 degrees typical for an arbitrary angular orientation
Output Modes	matrix, quaterion, bits
Sensor Range	gyros: +/-300 degrees/sec FS; accelerometers: +/- 2 G's FS; magnetometers: +/-1 Gauss FS
Digital Outputs	serial RS-232 or RS-485 optional with software programming
Output Data Rate	100 Hz (digital RS-232)
Serial Data Rate	19.2/38.4/115.2 kbaud, software prog.
Supply Voltage	+5.2 VDC min., +12 VDC max.
Supply Current	52 milliamps typical
Connectors	one keyed LEMO, two for RS-485 option
Operating Temperature	-40 to 70 degrees Celsius with enclosure; -40 to +85 degrees Celsius without enclosure
Enclosure (w/tabs)	64mm by 90 mm by 25mm; 2.5" by 3.5" by 1.0"
Weight	76 gr. with encl., 27.5 gr. without
Shock Limit	1000g (unpowered); 500g (powered)