An obstruction marking method for radar-based level finding, using an electronic level gauge, ELG, coupled to a tank and including a transceiver coupled to a processor , the method comprising: generating a first echo curve from a first reflected signal received when a material in said tank is at first level; identifying at least a first feature in said first echo curve to provide at least one suspected obstruction along with a first feature position ; generating a second echo curve from a second reflected signal when said material is at a second level in said tank that passes through said first feature position and identifying that an amplitude of said second reflected signal at said first feature position is above its amplitude in said first reflected signal at said first feature position; generating a third echo curve from a third reflected signal when said material is at a third level in said tank that is sufficiently above said first level and identifying that an amplitude of said third reflected signal at said first feature position is below the amplitude in said first reflected signal at said first feature position; identifying, based on first, second and third eco curves, said suspected obstruction as a verified obstruction being located at said first feature position; storing said suspected obstruction and said first feature position in said memory as a verified obstruction along with said first feature position; summing said first echo curve, said second echo curve and said third echo curve to generate a combined echo curve; and identifying within said combined echo curve at least one peak amplitude, wherein said suspected obstruction is identified as said verified obstruction being located at said first feature position, based on said generating combined echo curve and said identifying within said combined echo curve said at least one peak amplitude. generating a first echo curve from a first reflected signal received when a material in said tank is at first level; identifying at least a first feature in said first echo curve to provide at least one suspected obstruction along with a first feature position ; generating a second echo curve from a second reflected signal when said material is at a second level in said tank that passes through said first feature position and identifying that an amplitude of said second reflected signal at said first feature position is above its amplitude in said first reflected signal at said first feature position; generating a third echo curve from a third reflected signal when said material is at a third level in said tank that is sufficiently above said first level and identifying that an amplitude of said third reflected signal at said first feature position is below the amplitude in said first reflected signal at said first feature position; identifying, based on first, second and third eco curves, said suspected obstruction as a verified obstruction being located at said first feature position; storing said suspected obstruction and said first feature position in said memory as a verified obstruction along with said first feature position; summing said first echo curve, said second echo curve and said third echo curve to generate a combined echo curve; and identifying within said combined echo curve at least one peak amplitude, wherein said suspected obstruction is identified as said verified obstruction being located at said first feature position, based on said generating combined echo curve and said identifying within said combined echo curve said at least one peak amplitude. <EOS>