TY - JOUR TI - An improved marine radar system for studies of bird migration AU - Cooper, B AU - Day, R AU - Ritchie, R AU - Cranor, C T2 - Journal of Field Ornithology AB - Mobile laboratories equipped with marine radars were used to study the intensity altitude (above 25m), direction, behavior and ground speed of migrating birds in Alaska, Minnesota and South Dakota. A screen to reduce clutter on the radar display resulting from echoes of surrounding vegetation and other objects was developed. Other modification, including disengagement of the antenna motor use of a side-lobing shield and replacement of the slotted waveguide with a parabolic antenna, improved the system's ability to obtain information on flight altitudes. New features available on radars, such as the color monitor, alarm function, echo stretch function and plotting function, improved the radar system's ability to obtain information on movements of birds. DA - 1991/01// PY - 1991 VL - 62 IS - 3 SP - 367 EP - 377 UR - http://www.jstor.org/stable/20065804 LA - English KW - Wind Energy KW - Fixed Offshore Wind KW - Birds ER -