Résumé
The problems of pollution in population dynamics generally involve missing source terms, as well as missing initial or boundary conditions. This paper is concerned with identifying the pollution terms arising in the state equation of a population dynamics system with incomplete initial conditions. To this end, the so-called sentinel method is used. We prove the existence of such sentinels by solving a null-controllability problem with a control constraint. The key result of our work is an observability inequality of the Carleman type, adapted to the constraint.