
Pathfinder DVL Guide
April
2018
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Page 123
EU - Up/Down Orientation
Purpose
Sets the Pathfinder up/down orientation.
Format
EU
n
The EU command works with or without the # sign. For example, using EU or #EU are both
valid commands.
Range
n
= 0 or 1 (0 = down, 1 = up)
Default
EU0
Use the EZ-command (see
Description
In conjunction with the EZ command, EU is used to manually specify the orientation of
the Pathfinder.
The EU command can be used to align an upward pointing unit (e.g., mounted on a
submarine) if the roll source is in instrument coordinates. In this case, the EU command will
invert instrument coordinate roll. Use the #EI command instead if the roll source is
referenced to ship coordinates (see
EV - Heading Bias
Purpose
Corrects for electrical/magnetic bias between the Pathfinder heading value and the head-
ing reference.
Format
EV±nnnnn
The EV command works with or without the # sign. For example, using EV or #EV are both
valid commands.
Range
±nnnnn = -17999 to 18000 1/100ths of a degree
Default
EV0
Set as needed.
Description
EV is the heading angle that counteracts the local biasor magnetic variation (declination)
between the Pathfinder and the heading source. EV is added to heading (either in ship or
instrument coordinates) for use in velocity transformation and ensemble output.
Use the EA-command to correct for physical heading misalignment between the Path-
finder and a vessel’s centerline (see
).
Examples
1. A Pathfinder system is receiving heading from a compass. A magnetic variation chart
for the deployment area shows a variation of W3.5 (-3.5). To counteract the effects of this
magnetic field, enter a heading bias value of -3.5. To convert -3.5 to a EV-command value,
multiply the desired bias angle in degrees by 100: EV = -3.5 × 100 = -350 = EV-350.
2. Magnetic maps (such as NOAA) usually provides these types of reading: 10°10′W 1995
(9′E/year). This means the magnetic offset in the year 2001 at this location is
(- (10+10/60) + (9/60*6)) = -9.26666 degrees. Set the EV command value to EV-926.