A GPS receiver device comprises a receiver, an oscillator, a memory unit,
a temperature sensor, and a processor. The oscillator generates frequency
with drift errors occurring at a variety of different temperatures. The
memory unit stores coefficients of a plurality of polynomial equations.
Each polynomial equation fits a temperature range versus corresponding
drift errors. The temperature sensor detects ambient temperature of the
receiver. The processor determines which temperature range the ambient
temperature belongs to, reads the coefficients of the corresponding
polynomial equation from the memory unit according to the determined
temperature range, and calculates the drift error of the oscillator at
the ambient temperature.