Complex sentence: Signal processing of the successive recorded radar echoes allows the combining of the recordings from these multiple antenna positions--this process forms the "synthetic antenna aperture" and allows the creation of higher-resolution images than would otherwise be possible with a given physical antenna.
Split into simpler sentences: Signal processing of the successive recorded radar echoes allows the combining of the recordings from these multiple antenna positions. This process forms the "synthetic antenna aperture" and allows the creation of higher-resolution images than would otherwise be possible with a given physical antenna.