1. An aircraft-based terrain display system configured to display a terrain image having a perspective view, comprising: a radar system configured to measure terrain data in proximity to an aircraft; a memory coupled to the radar system and configured to store terrain data associated with the terrain data collected from the radar system; a processor coupled to the memory and configured to use the terrain data stored in memory to generate the terrain image; and wherein the radar system is configured to share time between measuring the terrain data and weather data so that during first sweeps the radar system provides radar beams configured to return weather data and during second sweeps the radar system provides radar beams configured to return terrain data; wherein the processor is configured to limit the downward direction of the view angle of the perspective view to a determined maximum downward angle that hides areas of radar shadow.