Reconnaissance is the oldest use of military aircraft. Planes were used in World War I as observation posts for artillery batteries & relied on the pilot or observers memory or a writing pad & pencil to record data. Reconnaissance is still an important task today. Even though satellites can handle the mapping of an area with relative ease, they aren't accurate enough to monitor columns of armour & troop formations. Modern reconnaissance aircraft have much more than a pencil & paper. Thermal imagers, laser designators & satellite uplinks are now standard in RAF reconnaissance aircraft.