Abstract: An element holder supporting an antenna element can be accommodated in a compact manner in an accommodated state and held such that the position thereof does not change due to an impact or the like, including at launch. An antenna device can be in an accommodated state of being accommodated in a casing and a deployed state of extending outside the casing. The antenna device includes an extension shaft member to extend from inside the casing in an axial direction, element holders movable along the extension shaft member, and a deployable antenna element. The element holder includes a concave portion formed in one surface of the element holder and a convex portion formed in another surface of the element holder. In the accommodated state, the convex portion of one of the element holders adjacent to each other enters into the concave portion of the other of the element holders.

Abstract: To provide an estimation device and the like configured to estimate a position of a signal generation source.

Abstract: An element holder supporting an antenna element can be accommodated in a compact manner in an accommodated state and held such that the position thereof does not change due to an impact or the like, including at launch. An antenna device can be in an accommodated state of being accommodated in a casing and a deployed state of extending outside the casing. The antenna device includes an extension shaft member to extend from inside the casing in an axial direction, element holders movable along the extension shaft member, and a deployable antenna element. The element holder includes a concave portion formed in one surface of the element holder and a convex portion formed in another surface of the element holder. In the accommodated state, the convex portion of one of the element holders adjacent to each other enters into the concave portion of the other of the element holders.

Abstract: To provide a signal processing device or the like that can estimate a data sequence including a signal with an unknown frequency band from among received signals having a small S/N ratio.

Abstract: To enable element holders to be arranged so as to be positioned at predetermined intervals when deployed. An antenna device 1 can be in an accommodated state of being accommodated in a casing and in a deployed state of extending to an outside from the casing. The antenna device 1 includes an extension shaft member 20 accommodated in a casing 10 in a state of being retracted in an axial direction, a plurality of element holders 30 each including an opening and stacked in the casing 10 in a state of the extension shaft member 20 being inserted through the openings, an antenna element 40 deployably held by the element holder 30, and a holding member that couples the plurality of element holders 30 to each other.