1. A permanent or stationary operational center, headquarters, or installation
The military established a fixed base in the region.
O exército estabeleceu uma base fixa na região.
2. In aviation, a facility providing services to aircraft at a fixed location
The airline operates a fixed base at the airport.
A companhia aérea opera uma base fixa no aeroporto.
3. In mathematics/geometry, a fixed reference point or foundation
We need a fixed base to calculate the coordinates.
Precisamos de uma base fixa para calcular as coordenadas.