European and Israeli firms have increasingly provided American defense manufacturers with effective competition. A recent example of this is LINAPS (Laser Inertial Artillery Pointing System), a computerized fire control system for towed artillery developed and sold by a British firm. LINAPS was actually the first such system for towed artillery and became available in 2001. Although LINAPS adds up to five percent to the cost of a towed gun it was soon found to be well worth the cost because of time saved and increased accuracy.
Computerized fire control systems have been around since the 1970s and until the 1990s were mainly used for direct fire (tank guns) weapons. Meanwhile towed artillery was getting by with programmable calculators and then portable computers to handle a lot of the math required to use towed guns effectively. Starting in the 1990s these computerized systems were developed for indirect fire artillery as well, mainly because the availability of GPS (satellite navigation systems) and laser range finders and target locators by forward observers (who identify targets and pass on the fire requests to the artillery). Systems like LINAPS use both GPS and inertial guidance (if GPS is jammed) systems to determine where the gun is and, once given the coordinates of the distant target, immediately calculate where to point the gun for the most accurate shot. For indirect fire weapons this labor intensive process has been gradually computerized since the 1970s but systems like LINAPS do it all and do it very quickly, effectively and reliably.
It was during World War I (1914 18) that artillery fire became largely indirect and fire control became a lot more complex. The gunners now usually fired at targets so far away they could no longer see the target or the effects of their fire. They had to rely on trigonometry, ballistics, maps, electronic communications, forward observers and registration by fire to direct the shells to their target. Despite these difficulties, the gunners didn't mind. If they couldn't see the enemy, the enemy couldn't see and shoot back at them. Unlike previous wars, where the artillery was a primary target, the guns now survived longer while their targets perished with greater frequency.
The scientific techniques behind modern artillery are quite simple. First, the flight of shells is fairly predictable if you take into account all of the elements that can alter the shell's path. Items like the tiny differences in the composition of different batches of propellant, wear and tear on the gun barrel, humidity, wind direction and speed and so on. The precise location of guns and targets is taken care of by using accurate maps and surveying equipment. Triangulation is used to determine the direction and elevation the guns will fire. Often a few rounds are fired and adjustments (“registration”) made before unleashing the entire barrage or concentration. During World War II, the United States perfected techniques that allowed one observer to control hundreds of guns; "every gun within range," as the saying went. Before this, each observer talked to, and controlled, one unit of guns. More complex and efficient communications and plotting systems were required to tie in a large number of artillery units and observers. The U.S. Army first developed this system in the 1930s and continues to lead in this development. With systems like LINAPS this mass fire system becomes even easier although the growing use of GPS guided shells and rockets is replacing the use of unguided shells.