Methods and apparatus for controlling frequency in a crystal oscillator are provided that allows for continued reception of GPS signal solution in a continuous high G environment. One method comprises measuring G-forces asserted on the crystal oscillator, determining a shift in frequency of the crystal oscillator due to the measured G-forces, determining a temperature that would shift the crystal oscillator's frequency back to a rate that would occur without the measured G-forces, and changing the temperature of the crystal oscillator based on the determined temperature to shift the crystal oscillator's frequency back to a rate that would occur if the G-forces were not present.