Site News  |   Monitor Keywords  |   Monitor Archive  |   Organizer  |   Account Info  |

Methods and systems utilizing doppler prediction to enable fusing

Methods and systems utilizing doppler prediction to enable fusing description/claims

This application is a divisional of U.S. patent application Ser. No. 12/025,907, filed Feb. 5, 2008 and entitled “METHODS AND SYSTEMS UTILIZING DOPPLER PREDICTION TO ENABLE FUSING” (the '907 Application), which, in turn, is a divisional of U.S. patent application Ser. No. 11/330,027 (U.S. Pat. No. 7,352,319), filed Jan. 11, 2006 and entitled “METHODS AND SYSTEMS UTILIZING DOPPLER PREDICTION TO ENABLE FUSING” (the '027 Application), which, in turn, claims the benefit of priority to U.S. provisional application Ser. No. 60/689,369 filed Jun. 10, 2005, the disclosure of which is incorporated herein by reference. Each of the '907 and the '027 Applications are incorporated herein by reference.

This invention relates generally to radar systems, and more particularly to methods and systems that utilize Doppler prediction to set a height of fusing, for example, for a radar based weapon system.

A radar based weapon system is configured to fuse the weapon of the system at various low altitudes so that the weapon will have optimum impact. A dual antenna (i.e. one transmit antenna and one receive antenna) radar system installation within the weapon system that has sufficient separation between the two antennas is not practical for smaller weapon systems. One reason separation between the antennas is important is to reduce an antenna leakage signal that propagates between the two antennas. Sufficient antenna separation to measure elevations near or at ground level such that antenna leakage signals do not interfere with altitude measurements typically cannot be efficiently incorporated into smaller weapon systems. In these smaller weapon systems there is simply not enough room to adequately separate the two antennas.

In smaller weapons systems that incorporate two antennas, the two antenna apertures are typically located near one another, significantly increasing the antenna leakage signal. Therefore, with a dual antenna weapon system it is difficult to accurately measure certain low altitudes because the antenna leakage signals interfere with time coincident ground return signals.

A single antenna installation using a duplexer is even more difficult to implement in smaller weapons. The reason is that one antenna systems do not even exhibit some of the inherent antenna leakage isolation found in the dual antenna systems. Rather, signals similar to leakage signals are internal to the radar. As a result, it is also difficult for a one antenna radar sensor on a small weapon system to measure altitudes near or at ground level.

In one aspect, a programmable circuit for controlling a detonation altitude of a radar equipped munition is provided. The circuit comprises means for calculating a velocity of the munition while the munition is operating in a pulse mode at an altitude greater than the desired detonation altitude and means, responsive to the means for calculating the velocity of the munition, for determining when the munition is at a reference altitude in order to operate the munition in a continuous wave transmission mode. The circuit further comprises means, responsive to the means for determining, for calculating a time representing when the vehicle will reach the desired detonation altitude based on the calculated velocity and the determined reference altitude, and means, responsive to the means for calculating the time representing when the vehicle will reach the desired detonation altitude, for generating a fusing signal to detonate the munition after the calculated time has passed.

FIG. 1 is a block diagram of a radar system for fusing weapon systems at or near ground level altitudes.

FIG. 2 is an illustration of transmit and receive spectrums for the system of FIG. 1.

FIG. 3 is an illustration of timing signals present in the system of FIG. 1.

The methods and systems described herein provide a solution for weapon system fusing at low altitudes by measuring a precision reference altitude where antenna leakage interference is not present and measuring the velocity of the vehicle as it approaches the ground. Once velocity of the munition is determined, the munition continues toward the ground until it encounters a ground return that is time coincident with a preset reference altitude gate, establishing the precision reference altitude. From these two measurements, a time delay can be used to accurately predict when the weapon system will attain an altitude at or near ground level, and a timing sequence is started. As a result, antenna leakage signals do not interfere with the operation of the sensor.

• Provisional Patent
• Utility Patent

• What Is a Patent?
• What Is a Trademark or Servicemark?
• What Is a Copyright?
• Patent Laws