Ground Stabilization: In ground stabilization mode true motion display of Radar is used & the Course & Speed is fed from GPS, hence the fixed objects on the PPI remain stationary. The movement of all moving objects is their movement overground. It is used for collision avoidance with fixed objects.
Sea stabilization: In sea stabilization mode relative motion display of radar is used & the Course is from Gyro course and speed is from log speed. Hence the fixed objects on the PPI appear to have a course & speed equal to the reverse course& speed of their own vessel. The movement of own vessel, fixed object & moving object is their movement through the water. This is ideal for collision avoidance action