According to one aspect of the present invention, there is provided a radar altimeter which utilizes a downward looking MIMO phased array to form multiple beams, covering a relatively wide sector, e.g., +/−60 degrees or thereabouts. The distance to the ground is then measured in each beam allowing the ground profile to be formed. The beams may be tilted forward to cover from about +90 degrees forward (horizontal) to about 30 degrees behind nadir. The provision of such a forward tilt gives a greater degree of coverage in the direction of approach vector to the ground. This additional cover enables the altimeter to more accurately detect other vehicles in the proximity to the current approach vector of the vehicle to the desired landing zone.