TM 9-1220-238-14
the intersection are recorded.
This procedure is
prescribed In (2) above so that the observers will not
repeated for as many flashes of the same gun as is
miss the succeeding rounds
practicable, up to a series of six flashes, if possible, at
(4) Six rounds are then fired and the azimuths of
which time a mean of the X and Y values recorded is
each burst are reported, plotted, and the coordinates
computed to give a mean center of flashes and,
recorded The site of each shot is reported and recorded
therefore, the observed location of the hostile battery
by the directing OP
f. High-Burst Ranging and Center of Impact
(5) A running total of the X and Y coordinates of
Adjustment.
each burst is recorded and from this the X and Y
(1) The coordinates of the observation posts having
coordinates of the mean center of bursts is computed
been previously plotted, a rough plot of the expected
and plotted
check point is made from coordinates furnished by the
(6) The range of this point, the center of Impact, is
firing battery commander if he has sufficient information
measured to the directing observation post.
to do so; otherwise a general area for observation is
(7) The Z coordinate, which is the elevation of the
designated
point of burst is calculated by the mil relation using the
(2) The azimuths to this point from each OP are
range and angle of site from the directing OP
determined by rotating the grid disk until the plotting
g. Test Problem The following test problem (fig. 1-4)
scale passes through the OP and the check point and
is given so that the operators may familiarize
then reading the plotting scale and vernier scale. These
themselves with the board and check the accuracy of
are transmitted to the individual OP's, together with the
the results obtained
approximate angle of site
(1) The coordinates of the observation posts are
(3) One round is fired and the azimuths are
given as follows:
reported and plotted The coordinates of this point are
OP1X = 26,000.0
Y = 10,000 0
not recorded since it Is plotted only as a check to see if
OP2X =22,300 0
Y = 08,400 0
each observer Is sighting properly on the same burst All
OP3X = 20,000 0
Y = 10,000 0
OP's not seeing the burst are given its approximate
OP4X = 21,300 0
Y = 13,700 0
azimuth (after it has been plotted) by the method
Figure 1-4. Test problem
1-6
