Air-to-surface missiles (ASM) have many of the same challenges as a surface-to-surface missile (SSM) for a comparable target type, flight path and control options, and range. For example, different seekers are needed for targets with a land vs. water background, especially if the seeker is radar-based. Some targets are better visualized with passive infrared, some with radar of various frequencies, and some with low-light television.
ASMs differ from SSMs, however, in that the pilot or weapons system operator may use a targeting pod, or a missile not yet launched, to visualize the target. A given missile can serve as a sensor before its last flight. When using missiles as sensors, however, considerations must be given to the sensor's power: if the sensing and cooling are electrical, they should draw power from the aircraft rather than draining battery power. The most restrictive situation is when the missile has a infrared viewer that is cooled by an onboard compressed gas supply.
Short-range ASMs, like the British Brimstone missile, U.S. AGM-65 Maverick or Russian Kh-29/NATO reporting name AS-14 KEDGE, have targets within line-of-sight. Longer-range ASMs, such as the French AS-30, U.S. AGM-84 SLAM or Russian Kh-59 NATO reporting name AS-13 KINGPOST, need a data link back to the launching aircraft if their guidance is man-in-the-loop, or, alternatively, need some kind of autonomous seeking. The longest-range ASMs, such as the U.S. AGM-86 ALCM, Israeli Popeye Turbo or Russian Raduga KSR-5/NATO designation AS-6 Kingfish, definitely need autonomous guidance, but increasingly need to provide mechanisms for battle damage assessment, such as a trailing camera.