Radar system and associated apparatus and methods

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured to analyse the stored signal information to individually detect (and optionally track) each of a multitude of targets (e.g. 100 or more targets, or 250, 500 or 1000 or 10,000 or more targets) that are simultaneously located in said FoS, and to extract and/or refine target information for each said target relating to at least one of a respective position and a respective characteristic of said target (such information may, for example, be represented in memory locations corresponding to more than 2 million, more than 10 million, more than 100 million, more than 500 million or more than 2 billion resolved range, azimuth, elevation and Doppler values, and may be updated at least four times per second, at least twice per second, at least once per second, or at least once every two seconds).

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured to analyse the stored signal information to individually detect (and optionally track) each of a plurality of targets that are simultaneously located in said FoS, and to extract and/or refine target information for each said target relating to at least one of a respective position and a respective characteristic of said target, even when each of said plurality of targets are within 3 NM (or within 2 NM, 1 NM or 0.5 NM) of one another.

A radar system as claimed in any preceding claim wherein said radar receiver is arranged to receive radar return signals returned from objects within a FoS that extends, relative to the radar receiver, at least one of:

• 90° or greater in azimuth;
• 6° or greater in elevation;
• and 5 km or greater in range.

A radar system as claimed in any preceding claim wherein said radar system is capable of acquiring and storing signal information for each of at least a majority of radar return signals received from within the entire FoS, wherein the FoS has a volume exceeding 3 cubic km, 5 cubic km, 10 cubic km, 100 cubic km, or even 500 cubic km.

A radar system as claimed in any preceding claim wherein the at least one process or processor is configured to respectively process complex radar return signals received within each of a sequence of several contiguous time periods of predetermined length, including said first and second time period, to acquire and store respective signal information for each said time period.

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured for analysing stored signal information, retrospectively following detection of a target, and for refining extracted target information for a detected target based on signal information stored before a signal frame in which that target was detected.

A radar system as claimed in any preceding claim wherein the at least one process or processor is configured to respectively process radar return signals received within each of a sequence of several contiguous time periods of predetermined length, including said first and second time period, to acquire and store respective signal information for each said time period;

• and to analyse the stored respective signal information for each said time period and for an extended time period comprising a plurality of said contiguous time periods to extract and/or refine target information for any detected targets.

A radar system as claimed in any preceding claim wherein each said time period has a predetermined length equal to an initial dwell time length (which may, for example, be defined for each resolution element in range, azimuth or elevation) for said radar system.

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured for extracting information relating to performance of at least one of a pilot and an aircraft with respect to at least one performance criterion and wherein said radar system is configured for providing said information relating to performance of at least one of a pilot and an aircraft to a user.

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured for providing target information relating to each of a plurality of detected targets located at a respective three-dimensional real-space position within said FoS for output, via a three-dimensional visualisation system, or at a respective three-dimensional virtual-space position corresponding to the three-dimensional real-space position of that detected target.

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured for extracting target information relating to a detected target using a plurality of different extraction methods, wherein each extraction method is tailored to a different respective surveillance function.

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured for analysing acquired signal information to extract target information relating to the position or movement of the target within the FoS and separate target information relating to a smaller part of the target (e.g. a part that is moving relative to another part of the target such as wing tips or nose and tail during a turn, or control surfaces).

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured for defining a sub-volume of said FoS in which an enhanced surveillance procedure is to be applied, for analysing signal information for radar returns reflected from within said sub-volume of said FoS in accordance with said enhanced surveillance procedure, for analysing signal information for radar returns reflected from outside said sub-volume of said FoS in accordance with another surveillance procedure that is different to said enhanced surveillance procedure.

A radar system as claimed in any preceding claim wherein said at least one process or processor is configured for analysing acquired signal information to extract target information relating to surface (e.g. land borne and/or water borne) targets.

A radar system as claimed in any preceding claim wherein said radar system is a non-cooperative radar system.

A radar receiver configured to perform the function of the radar receiver of the radar system claimed in any preceding claim.

A radar system for providing information relating to a three-dimensional field of surveillance (FoS) having a volume exceeding one cubic kilometre, the radar system comprising:

• at least one radar transmitter operable to persistently illuminate said FoS with a sequence of pulses of radiation at a pulse repetition frequency (PRF);
• at least one radar receiver arranged to persistently monitor said FoS to receive radar return signals returned from objects within the FoS, as a result of said persistent illumination of said FoS by the at least one radar transmitter;
• and at least one process or processor configured to process return signals received from within said FoS, and to store acquired signal information for each of at least a majority of radar return signals received from within the entire FoS within a predetermined time period, in a memory in association with information identifying at least one of respective beam in which that return signal was received and a respective receiver element at which that respective return signal was received, whereby to provide a representation of substantially the entire FoS in memory.