is not desirable to overfly the target with the aircraft at an altitude sufficient for dive-bombing or level bombing. Such cases include heavy anti-air defenses such as AAA and SAMs, when deploying powerful weapons such as "iron bombs" or even tactical nuclear bombs, and the use of limited-aspect targeting devices for guided munitions. To counter air defenses en route to the target, remaining at a low altitude for as long as possible allows the bomber to avoid radar and visual tracking and the launch envelope of older missile systems designed to be fired at targets overflying the missile site. However, a level pass at the target at low altitude will not only expose the aircraft to short-range defenses surrounding the target, but will place the aircraft in the bomb's blast radius. By executing a "pop-up" loft, on the other hand, the pilot releases the munition well outside the target area, out of range of air defenses. After release, the pilot can either dive back to low altitude or maintain the climb, in either case generally executing a sharp turn or "slice" away from the target. The blast produced by powerful munitions is thus (hopefully) avoided. The value of toss-bombing was increased with the introduction of precision-guided munitions such as the laser-guided bomb. Previous "dumb bombs" required a very high degree of pilot and fire control computer precision to loft the bomb accurately to the target. Unguided loft bombing also generally called for the use of a larger bomb than would be necessary for a direct hit, in order to generate a larger blast that would destroy the target even if the bomb did not hit accurately due to windage or computer/pilot error. Laser-targeting (and other methods like GPS as used in the JDAM system) allows the bomb to correct minor deviations from the intended ballistic path after it has been released, making toss-bombing as accurate as level bombing while still providing most of the advantages of toss-bombing using unguided munitions. However, the targeting pods used to deliver guided munitions generally have a limit to their field of view; most specifically, the pod usually cannot look behind the aircraft at more than a certain angle. Lofting the bomb allows the pilot to keep the target in front of the aircraft and thus within the targeting pod's field of view for as long as possible. "Dive-tossing" is generally used at moderate altitude