Adaptive Missile Guidance Using Gps

Abstract

Laser guided missiles use a laser of a certain frequency bandwidth to acquire their target. GPS/inertial weapons are oblivious to the effects of weather, allowing a target to be engaged at the time of the attacker's choosing. GPS allows accurate targeting of various military weapons including ICBMs, cruise missiles and precision-guided munitions. Artillery projectiles with embedded GPS receivers able to withstand accelerations of 12,000 G have been developed for use in 155 mm. GPS signals can also be affected by multipath issues, where the radio signals reflect off surrounding terrain; buildings, canyon walls, hard ground , etc. These delayed signals can cause inaccuracy. A variety of techniques, most notably narrow correlator spacing, have been developed to mitigate multipath errors. Multipath effects are much less severe in moving vehicles. When the GPS antenna is moving, the false solutions using reflected signals quickly fail to converge and only the direct signals result in stable solutions

Concept of missile guidance 

Missile guidance concerns the method by which the missile receives its commands to move along a certain path to reach a target. On some missiles, these commands are generated internally by the missile computer autopilot. On others, the commands are transmitted to the missile by some external source.

Missile guidance using radar signal 

Many machines used in battle, such as tanks, planes, etc. and targets, such as buildings, hangers, launch pads, etc. have a specific signature when a radar wave is reflected off of it. Guided missiles that use radar signatures to acquire their targets are programmed with the specific signature to home in on. Once the missile is launched, it then uses its onboard navigational array to home in on the preprogrammed radar signature. Most radar guided missiles are very successful in acquiring their targets, however, these missiles need a source to pump out radar signals so that they can acquire their target. The major problem with these missiles in today’s battlefield is that the countermeasures used against these missiles work on the same principles that these missiles operate under.

Elements of GPS 

GPS has three parts: the space segment, the user segment, and the control segment. The space segment consists of a constellation of 24 satellites plus some spares, each in its own orbit 11,000 nautical miles above Earth. The user segment consists of receivers, which we can hold in our hand or mount in a vehicle. The control segment consists of ground stations that make sure the satellites are working properly.

Conclusions 

The proliferation of GPS and INS guidance is a double-edged sword. On the one hand, this technology promise a revolution in air warfare not seen since the laser guided bomb, with single bombers being capable of doing the task of multiple aircraft packages. In summary, GPS-INS guided weapons are not affected by harsh weather conditions or restricted by a wire, nor do they leave the gunner vulnerable for attack. GPS guided weapons, with their technological advances over previous, are the superior weapon of choice in modern day warfare.