The relative position of the OT line with respect to
to accompany the unit he is supporting, thereby giving
the mortar-target line does not affect the forward
it close and continuous fire support.
observer's procedure in adjusting observed fire. The
2. One forward observer can mass the fires of all
forward observer makes his spottings and gives his
mortar and artillery units within supporting range on a
connections with respect to the OT line. He determines
errors and sends confections to the FDC. The FDC
3. The combat Seabee can fill any gaps in the
converts these corrections to appropriate fire
forward observer's field of view, thus giving better
commands. This is done by plotting the forward
indirect fire support to infantry units.
observer's corrections so the mortar section can place
the next burst at the point designated by the observer. To
4. It simplifies the work of the forward observer
assist in the reporting of targets, each FO may be given
and places the burden of computing on personnel at the
a freehand sketch or a suitable map showing the
FDC who usually work under better conditions.
registration point and any other reference points whose
5. It eliminates the necessity of training a large
chart locations are known at the FDC.
number of forward observers to compute correction
Terminology used by forward observers has been
factors and requires only relatively few trained
standardized throughout the Army, Navy, and Air Force.
computers at the FDC.
Therefore, the FO of a mortar section who is familiar
6. The system does not depend entirely on the
with the basic principles of forward observation
accuracy of the forward observer's azimuth to the target.
procedures is capable of adjusting the fire of any type
Errors as great as 100 mils can be made without having
of indirect-fire weapon. To adjust the fire of indirect
any appreciable effect on the adjustment. Larger errors
weapons of units outside his own company, he
throw the burst off the observer-target (OT) line;
establishes communication with the firing unit and
however, such errors are easily detected by the
maintains it throughout the adjustment.
computer, and the correct azimuth can be quickly
determined by connecting two on-line bursts on the
plotting board and reading the azimuth of this line.
Location of Target
The observer may report the location of a target for
the FDC by one of three different methods: grid
Forward Observer Procedures
coordinates. These are listed in the order of preferred
When the FDC controls the fire of mortars emplaced
in a section, anyone of the three forward observers can
GRID COORDINATES. The forward observer may
be used to adjust fire for the unit. Each forward observer
referring to a map or photomap. In this method, the
carries and operates a radio. The forward observer also
forward observer sends an eight-digit coordinate that
carries a telephone and a reel of wire. When necessary,
locates the target to the nearest 10 meters.
the mortar squad leaders supplement or relieve the
SHIFT. The forward observer reports the location
of a target through a shift or change from a reference
Each FO is assigned to observe and conduct fire for
point, which may be the registration point, a marking
a particular rifle unit in the company sector or zone of
round (to help identify the round, the observer may
operation. He is also charged with maintaining contact
request a smoke round or airburst), a numbered target,
with the supporting unit and keeping himself and the
or any other point whose chart location is known at the
FDC completely informed of the tactical situation. His
FDC. He gives the shift as a correction in meters to the
primary activity is to watch the movement of the
nearest 10 for deviation and 25 for range from the
supporting unit and to adjust mortar fire on those targets
reference point. When either the direction or altitude of
interfering with the mission of that unit. His secondary
the target is the same as that of the reference point, he
mission is to provide military information to higher
omits the connection. The forward observer determines
echelons through his means of communication. He does
the shift as follows:
this through observing and correcting of prearranged
fire and by adjusting fire on targets of opportunity that
1. DEVIATION. He measures the deviation in mils
he observes or which are identified to him by others.
from the reference point to the target with binoculars and