The measuring system parameters according to the theory of light scattering and reflection are chosen to optimize the system.

So the third chapter focuses on the measuring system. The operating principle (Light extinction method), the factors which influence the result and the resolvent to avoid them are explained.

In the past 13 years, scientists have discovered more than 300 planets outside our solar system, but they have done so indirectly, by measuring changes in gravity, speed or light around stars.