The AASM (air-to-ground modular weapon) is a weapon carried by fighter aircraft that can be effortlessly fired ("fire and forget") from stand-off distance (15km for low-altitude firing; 50km for high-altitude firing). It is currently developed for Mirage 2000 and Rafale air-to-ground combat aircraft. Rafales are capable of carrying up to six of these missiles. Each missile can be aimed independently at a particular target, which it will hit with a 10m accuracy with the inertial/GPS all-weather version and only a few meter accuracy with the night/day infrared terminal
guidance version.
Despite the purely ballistic nature of the initial ammunition (a 250kg standard or penetration bomb), adding a sophisticated guidance kit to the front and a range increasing kit to the rear results in a true "global system" as the following features illustrate:
> The missile is equipped with a guidance/hybrid navigation (Kalman filtering) system which combines the position supplied by a GPS receiver and "inertial" data from a gyroscopic/accelerometric unit (IMU = Inertial Measurement Unit).
> While the missile is carried by the plane, this system "aligns" with the inertial navigation (high precision)/GPS of the plane whose Kalman filter operates in "in-flight alignment" mode.
> In-flight alignment means that the missile’s IMU receives data from the aircraft navigator and adjusts its own data by "navigating side by side". Note that if the aircraft has taken off from an aircraft carrier, it will have performed a similar alignment ("at-sea alignment") to match the inertial/GPS (and more) system of the aircraft carrier, also developed by Sagem.
> When it is fired, the missile is guided autonomously through its own hybrid navigation system from the release point to the target, whose coordinates were prepared at the same time as the aircraft flight plan, using a mission planning system.
> With the inertial/GPS all-weather AASM version, the objective of the terminal guidance phase is to ensure the missile reaches its target at the indicated impact angle and speed.
With the night/day metric AASM, the terminal guidance phase also adjusts the missile navigation to the true target by matching the image viewed through the infrared sensor and a target model stored in the missile memory. This model will already have been drawn up on the ground using a mission planning system and, for example, a satellite image. Once again, it is Sagem that develops the infrared sensor, the image processing and the AASM mission preparation module.
This is therefore a very "global" system which draws on a wide range of specialities we would have difficulty imagining initially. This global system is also "versatile", i.e. weaponry can be configured according to the mission of the particular day and several systems are provided in one, along with a diverse number of weapons (up to six) for each aircraft.
