Knowing the exact airspeed of your aircraft is very important for maintaining proper control of your aircraft as well as planning for various maneuvers.
Currently this job is done by air-pressure-based systems which use small tubes, known as pitot tubes, that protrude from aircraft.
These, along with small holes positioned at right-angles to the direction of flight, help the on board computers measure the air pressure both inside and outside the aircraft.
The difference between these two pressures is what helps the system determine the current airspeed. As you can guess this system is quite complicated and prone to problems as well.
Some of these problems include, the sensors being prone to icing up under cold conditions, getting damaged through collisions with birds, as well as not being accurate at low speeds.
To take care of these problems, researchers at BAE Systems have developed a new system, known as the Laser Air Speed Sensing Instrument (LASSI).
As the name suggests, this new system replaces the current equipment with an ultraviolet laser. This laser is then used to bounce light off the surrounding air molecules.
This is done in order to measure the change in the color of the reflected beam, which is caused by the Doppler Effect. The larger the degree of change, the fast the speed of the aircraft.
This system provides a more accurate reading of aircraft velocity at all sorts of speeds and altitudes, as it is free from the inconsistencies of air pressure based systems.
The BAE Systems team has already conducted all the relevant testing proving their claims, and is now looking at ways to scale down the system, so that it can be easily adapted to both commercial and military aircrafts in the coming years. We will keep you updated on the progress.