Bullet approach warning system and method

A system for warning a helicopter of an approaching bullet using existing sensor systems, said system comprising:

• an RF transmitting system;
• an RF receiving system;
• a hostile fire indicator for detecting a small arms weapon firing from at least one location in the vicinity of a helicopter and providing a bearing from said helicopter for said at least one location where said small arms weapon firing was detected;
• a warning system, and
• a bullet approach warning functionality, said bullet approach warning functionality comprising:
• means for determining a detection area and detection time window for a bullet fired from said small arms weapon;
• means for determining at least one antenna of said means for transmitting an RF signal and said means for receiving RF signals that are covering a sector including said bearing of said detected small arms weapon firing;
• means for determining a timing sequence and allocating at least one time segment for transmitting said RF signal and at least one time segment for receiving RF signals during said detection time window, and
• means for commanding said means for transmitting an RF signal to emit said RF signal at a predetermined frequency during said at least one time segment allocated for transmitting said RF signal, and
• means for commanding said means for receiving RF signals to receive RF signals near said predetermined frequency during said at least one time segment allocated for receiving RF signals;
• wherein said RF receiving system processes RF signals received during said at least one time segment allocated for receiving RF signals and determines whether an RF signal reflected from said RF signal emitted from said RF transmitting system is present in said RF signals received during said at least one time segment allocated for receiving RF signals, and
• said warning system outputs a warning where said RF signal reflected from said RF signal emitted from said RF transmitting system is detected.

A method for warning a helicopter of an approaching bullet using existing sensor systems, said bullet approach warning method comprising the steps of:

• detecting a small arms weapon firing at least one bullet from at least one location in the vicinity of a helicopter;
• providing a bearing from said helicopter for said at least one location where said small arms weapon firing was detected;
• determining a detection area and detection time window for said at least one bullet fired from said detected small arms weapon firing;
• determining at least one antenna of an on-board RF transmitting system and at least one antenna of an on-board RF receiving system that cover a sector including the bearing of said detected small arms weapon firing;
• determining a timing sequence and allocating at least one time segment for transmitting an RF signal and at least one time segment for receiving RF signals during said detection time window;
• commanding said RF emitting system to emit said RF signal at a predetermined frequency during said at least one time segment allocated for transmitting RF signals, and commanding said RF receiving system to receive RF signals near said predetermined frequency during said at least one time segment allocated for receiving RF signals;
• processing said RF signal received during said at least one time segment allocated for receiving RF signals;
• determining whether said RF signal received during said at least one time segment allocated for receiving RF signals includes at least one RF signal pulse reflected from said RF signal emitted from said RF emitting system, and
• outputting a warning where at least one RF signal pulse reflected from said RF signal emitted from said RF emitting system is detected.