A method for determining a frequency correction and a symbol rate correction for transmissions from a user terminal in a satellite communications system comprises determining a frequency of a signal received at the user terminal, and determining a symbol rate of the signal received at the user terminal. The method also comprises computing an error associated with an oscillator at an outdoor unit of the user terminal, and computing an error associated with an oscillator at an indoor unit of the user terminal. The method also comprises computing a transmit frequency correction for the user terminal based on the error of the oscillator at the outdoor unit and the error of the oscillator at the indoor unit, and computing a transmit symbol rate correction for the user terminal based on the error of the oscillator at the indoor unit.