Paired observation

German artillery observers (1916)

American Advanced Artillery Observer Adjusts Fire (2011)

Paired observation or SN is a military term denoting a type of observation that is carried out simultaneously from two or three points combined into a single system ^{[1] [2] [3]} .

Paired observation is widely used in artillery for servicing firing to accurately determine the coordinates of shell explosions, the location of targets and other objects on the ground ( landmarks , reference points, etc.) ^{[2] [3]} . For this, the armament of the artillery units has a wide range of various instrumentation: theodolites , artillery compasses , etc. ^[3]

The spatial separation of the points from which the conjugate observation is carried out is called the base ^[1] , and these points themselves are called the points of conjugate observation ^[3] . The point at which the commander responsible for organizing the observation is located is called the main one, and all the others are called side (right and left) ^[3] . Between all points, telephone or radio communications are organized, their topographic reference is made on the ground with the determination of coordinates, altitudes, base length and directional angle of the base from the right point to the left ^[3] . Orientation of artillery observation devices can be carried out either by mutual sighting, or, in the absence of mutual visibility, according to a common reference point for all points ^[3] .

The desired coordinates of the target are estimated by measuring from each point the horizontal angles between the line of mutual sighting of the instruments or between the direction lines to a single landmark and the direction to the target, followed by solving the direct geodesic problem ^[3] . The introduction of additional observation points increases the accuracy and reliability of the calculation of coordinates, increases the range of target acquisition and expands the reconnaissance capabilities of the unit ^[3] .