How to calculate the jerk from acceleration data?

I have speed data from the GPS transmitter of a Truck which reports the speed of the vehicle at a fixed time interval. I can calculate the acceleration/deceleration of the truck by doing a $$\frac{v_2-v_1}{t_2-t_1}$$ calculation. However, can I calculate the jerk in the same manner? That is $$\frac{a_2-a_1}{t_2-t_1}$$? Will that be a correct thing to do?