Back Echoes and Reflection
If a radar is sited in view of a large, flat, non
horizontal, reflecting surface such as the side of a building,
reflections of meteorological targets (and permanent echoes) may be
observed in that 'false' direction. Every attempt is made to avoid this
situation when siting a radar, but it is not always possible to avoid
being ‘built out’ later. Multiple reflections, producing several
returns of energy to the radar from different directions but the same
target may occur in built up areas.