MAG/NAV/M1 - Missing data

Kearfott SEANAV Fiber Optic Gyro system came to end of life on Nov 3, 2012.  A rental 
IXSEA Hydrins III system was secured to replace it with normal operation Dec 6, 2012.

The SEANAV raw GPS data was captured during much of this missing data period yielding only 
Date, Time, Latitude, Longitude, NorthVelocity (m/s), EastVelocity (m/s) records at 1Hz. 
 The gps-only data are available as nav: magnavgpsM1.a1.

Some SEANAV type full motion data are available during a Dec 4 thru Dec 6 testing period 
by special request to the mentor.

Use magnavgpsM1.a1

• Ship surge acceleration along ship length, positive forward(surge_acceleration)
• Yaw angular rate, clockwise bow rotation positive(yaw_angular_rate)
• Ship sway velocity, starboard-to-port displacement, positive to port(sway_velocity)
• base time in epoch(base_time)
• Heave directional velocity, up positive(heave_velocity)
• Ship sway, starboard-to-port displacement, positive to port(sway)
• Roll angle reported by tilt table, positive is port side up(roll)
• North Latitude(lat)
• Ship sway acceleration starboard-to-port, positive to port(sway_acceleration)
• Seanav monitor value as true/false conditions(seanav_monitor)
• Seanav system mode(seanav_mode)
• -180.0 - +180.0(alt)
• time_in_seconds_since_volume_start(time)
• Time offset from base_time(time_offset)
• Heave directional acceleration, up positive(heave_acceleration)
• Roll angular rate, positive is port side up(roll_angular_rate)
• Free running cycle counter(cycle_count)
• Ship yaw, axis vertical, positive is clockwise rotation(yaw)
• Ship surge velocity along ship length, positive forward(surge_velocity)
• Ship surge displacement along ship length, positive forward(surge)
• lon(lon)
• Pitch angular rate, bow up positive(pitch_angular_rate)
• Pitch, bow up positive(pitch)
• Heave: up positive(heave)