MAG/NAV/M1 - Missing data

Data are missing and unrecoverable.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - Missing data

Missing single hour of data. SEANAV raw data file was not recovered for unknown reason.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - Missing data

TSI instrument was removed without mentor knowledge.  Associated TSI serial port was 
required for NAV data collection.  NAV data collection resumed after substituting null device 
for missing TSI serial port.

Surrogate motion data sources might be reconstructed depending on specific requirements.  
Contact SEANAV mentor for discussion.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

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.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - Missing data

The Hydrins III rental system hung.  Problem was not corrected until ship was in port 
allowing for mentor access.

Depending on the specific need surrogate data might be constructed from other sources.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - Missing data

Loss of ship power shut down most instruments.  Little hope for surrogate data sources.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/ALL/M1 - Ship in Dry Dock

Ship was at dry dock without MAGIC instruments or in transit to or from dry dock.  No 
instrument data available.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - Missing data

Brief period of missing data because serial port hung.  The seanavlogd auto-check which 
ran every ten minutes restarted the system.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - Brief data outages during testing

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• yaw_angular_rate
• Surge: bow forward positive(surge)
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - Missing data

Data loss due to AMF2 data system computer and virtual machine problems.

Note that the data gap begins when ship was docked at Long Beach.  NAV data are not 
generally used when ship is at dock.  Ship left Long Beach on June 8, 2013 at 11:25.  So data 
gap while at sea is June 8, 2013 11:25 to 17:02 UTC.

Surrogate data sources may be possible depending upon actual requirements. Contact SEANAV 
mentor for discussion.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• Surge: bow forward positive(surge)
• yaw_angular_rate
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - SEANAV system end-of-life issues begin

When initially purchased, it was not realized that the SEANAV Fiber Optic Gyros (FOG) have 
a predictable life time before degradation and failure. In October 2012, the FOG 
end-of-life issues started to appear.  The problem was not diagnosed immediately.  

When the internal FOG lasers go below a selected intensity the SEANAV enters a "NO GO" 
mode and data ceases.  When this failure cause was finally identified we learned it was 
possible to delay the failure by adjusting internal laser thresholds somewhat, not affecting 
data quality.  

The specified data outages are due to these NO GO periods and data resumed when laser 
thresholds were further lowered.  Ultimate failure was however reached on Nov 1, 2012 at 
16:24 UTC.

GPS data from the SEANAV was still available and data records with date, time, latitude, 
longitude, northvelocity (m/s), eastvelocity (m/s) were collected into a new data stream 
named magnavgpsM1.a1.  These data do not contain any ship attitude data such as 
roll/pitch/yaw.  

Note that ship attitude data is also collected from motion sensors associated with other 
MAGIC instruments.  These alternate/surrogate motion data sources might be useful 
depending on the particular need.  Contact the SEANAV mentor for discussion.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• yaw_angular_rate
• Surge: bow forward positive(surge)
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• surge_acceleration
• North latitude(lat)
• sway_acceleration
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)

MAG/NAV/M1 - System configuration errors at set-up

The newly installed Hydrins III system was incorrectly configured resulting in missing GPS 
data and some data products were therefore affected.

• Heading from geodetic north, clockwise bow rotation(yaw)
• East longitude(lon)
• heave_acceleration
• sway_acceleration
• North latitude(lat)
• surge_acceleration
• Heave directional velocity, up positive(heave_velocity)
• roll_angular_rate
• Surge directional velocity, bow forward positive(surge_velocity)
• Sway directional velocity, toward port positive(sway_velocity)
• yaw_angular_rate

MAG/AOS/ALL/M1/S1/S2 - Ship in port

The ship was in port during these periods and the measurements may be affected by various 
sources (overhead cranes, anthropogenic sources, etc).

Note: Dates and times were found by looking at the NAV datastream.  The standard deviation 
of pitch, roll, and surge velocity were used to determine when the ship was slowing down 
to enter port or speeding up to leave port.  Thresholds used; pitch (0.01), roll (0.01), 
surge velocity (3.0)

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Heave: up positive(heave)
• Sway directional velocity, toward port positive(sway_velocity)
• yaw_angular_rate
• Surge: bow forward positive(surge)
• Heading from geodetic north, clockwise bow rotation(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• Altitude above mean sea level(alt)
• Pitch angle of the ship(pitch)
• East longitude(lon)
• cycle_count
• seanav_monitor
• North latitude(lat)
• sway_acceleration
• surge_acceleration
• Heave directional velocity, up positive(heave_velocity)
• time
• Roll: starboard down positive(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)