Field ArTillery - US Army Center Of Military History

122 The OrganizaTiOnal hisTOry Of field arTillery
without adjustment on other targets. The technique was called registration. To aid in
registration, the American field artillery used weather data collected by the French
and transmitted it to the field through the Artillery Information Service. 84
The AEF’s Artillery Information Service had the responsibi lity of communicating
all target information by daily bulle tin to all levels down to battery commanders.
The key personnel were the artillery intelligence officers, who were stationed
at levels from army artillery through battalion and sometimes the battery. At each
level, the artillery intelligence officer unified target information, exchanged this information
with other artillery intelligence officers, advised the artillery commander,
maintained a plot of enemy locations, disseminated meteorological data, coordinated
the observation and adjustment of fire, and supervised sound ranging (the technique
of locating targets by sound waves) and flash ranging (the technique of locating
targets or adjusting friendly batteries by sighting their fire). He also worked closely
with conventional intelligence officers throughout the AEF. 85
In addition to sound ranging and flash spotting, aerial observation by airplane
and balloon became effective means of acquiring targets. Aerial observers were
listed as artillerymen in the regimental tables of organization, but upon completing
their training at Fort Sill, they were usually taken over by the newly forming Air
Service. This trend, of course, made regimental commanders reluctant to send men
for training as aerial observers. Retaining the men in the Field Artillery branch but
detailing them to the Signal Corps, which then controlled the Air Service, partially
solved the problem. Nevertheless, difficulties in obtaining enough aerial observers
with sufficient training continued throughout the war. 86
In daylight and good atmospheric conditions, the use of airplanes permitted
rapid and accurate observation. As a result, salvos could be sensed and often their
error in reference to the target could be valuated exactly. The aerial observers communicated
to the ground by wireless, searchlight, weighted messages, and rockets.
The ground receiving station communicated with the plane by identification panels
and sometimes searchlights. The identification panels, which aerial observers found
more convenient, were visible to the enemy; the reverse was true with searchlights.
Another observation venue was balloons, which could not ascend above 1,500
meters (1,640.4 yards) and were obliged to keep at least 7 kilometers (4.3 miles)
from enemy lines. Portions of the terrain were thus hidden from the observer at
any given observation point. Compared to airplanes, balloons were used only as an
auxiliary in adjusting artillery fire and generally performed only surveillance missions.
Communication with the balloon observer was by telephone. 87
84 Alexander T. Jennette, “Mass Fire in World War,” pt. 1, Field Artillery Journal, May-June 1975,
pp. 40–41.
85 Ibid., pp. 42–43; Manual for the Artillery Orientation Officer . . . (Washington, D.C.: U.S.
Government Printing Office, 1917), p. 37. Sound-ranging and flash-ranging organizations were authorized
as engineer units.
86 Sunderland, Field Artillery School, p. 68.
87 Manual for the Battery Commander, Field Artillery, 75-mm. Gun (Washington, D.C.: U.S.
Government Printing Office, 1917), pp. 138, 140. For information concerning aerial observation in World
War I, see Raines, Eyes of Artillery, pp. 10–14.