Patent attributes
A seismic weight dropper arrangement for a drone. The arrangement comprises a winch assembly attachable to a drone and comprising an actuator and spool with a cable windable thereon. Arrangement also includes a seismic source assembly comprising a housing and a mass suspended within the housing via at least one resiliently elastic biasing element, such as a coil spring. The seismic source assembly is fast with the cable and the actuator configured selectively to eject the seismic source assembly from the drone under the influence of gravity. The resiliently elastic biasing element has a predetermined modulus of elasticity to facilitate the mass impacting the housing when the housing impacts a surface after such ejection from a predetermined height above the surface.