Rotating antenna for ionizing-radiation sensing via far-field pattern perturbation

A method comprising:

• selecting an active mode from a group of modes comprising at least a coarse-scan mode and a fine-scan mode;
• rotating, by a rotation drive of a transmitter antenna, at least one radiator about a rotation axis, wherein at least one of the at least one radiator is, at least in part, coated with a radiation-sensitive material;
• emitting, by the radio-frequency transmitter antenna, a far-field radiation pattern;
• receiving, at a radio-frequency receiver antenna, a received signal indicative of the far-field radiation pattern emitted by the transmitter antenna, wherein exposure of the radiation-sensitive material to ionizing-radiation perturbs the far-field radiation pattern;
• generating antenna response data indicative of one or more characteristics of the far-field radiation pattern based on the received signal;
• computing at least one of a presence-confidence metric indicative of exposure to ionizing-radiation and/or a traveling direction of an ionizing-radiation source;
• and
• responsive to the presence-confidence metric exceeding a threshold in the coarse-scan mode, selecting the fine-scan mode as the active mode.

A method for operating a system comprising a plurality of geographically distributed antenna pairs communicatively coupled to a central controller including at least one processor and non-transitory memory storing instructions, each antenna pair including a radio-frequency transmitter antenna and a corresponding radio-frequency receiver antenna, the transmitter antenna having a rotation drive configured to rotate a radiator about a rotation axis and at least a portion of the radiator being coated with a radiation-sensitive material whose exposure to ionizing-radiation perturbs a far-field radiation pattern of the corresponding transmitter antenna, the method comprising:

• obtaining, from each receiver antenna, a received signal indicative of the far-field radiation pattern emitted by corresponding transmitter antenna;
• generating, for each received signal, antenna response data indicative of one or more characteristics of the far-field radiation pattern;
• computing, for each antenna response data associated with respective received signal, at least one of a local presence-confidence metric and/or a local traveling direction of an ionizing-radiation source;
• associating at least one of respective local presence-confidence metric and/or respective local traveling direction of an ionizing-radiation source with a geospatial location.