초록 ▼

Embodiments for providing dynamic azimuth scanning are generally described herein. In some embodiments, weather survey measurements are performed to estimate environmental losses as a function of azimuth angles. Gain improvements are determined based on the amount of energy increase used at differen

Embodiments for providing dynamic azimuth scanning are generally described herein. In some embodiments, weather survey measurements are performed to estimate environmental losses as a function of azimuth angles. Gain improvements are determined based on the amount of energy increase used at different azimuth angles derived from the azimuth loss survey measurements. A gain profile is generated based on the determined gain improvements. An azimuth offset profile is derived using the gain profile to define azimuth angles where progressive scan back is used in the area of environmental losses to provide additional power and to define azimuth angles where progressive scan forward is used in regions of low loss. Dynamic electronic azimuth beam steering provides a near-constant average target detection range as a function of azimuth in the presence of non-uniform loss.

대표청구항 ▼

1. An active electronically scanning array (AESA), comprising: a plurality of radiating elements, a radiating element including a transmit-receive module for providing transmitter and receiver functions for each radiating element; anda controller, coupled to the plurality of transmit-receive modules

1. An active electronically scanning array (AESA), comprising: a plurality of radiating elements, a radiating element including a transmit-receive module for providing transmitter and receiver functions for each radiating element; anda controller, coupled to the plurality of transmit-receive modules, the controller arranged to provide dynamic electronic azimuth beam steering over a given search area, wherein the dynamic electronic azimuth beam steering is configured to vary a net azimuth beam scan rate, wherein the dynamic electronic azimuth beam steering provides a rate of forward scan or back scan at azimuth angles identified according to an azimuth offset profile, and wherein the dynamic electronic azimuth beam steering comprises configuring the AESA to provide:progressive scan back rotation at azimuths where dwell time is increased as compared to a nominal dwell time for the AESA, the nominal dwell time corresponding to a dwell time for the AESA where there is no electronic scan; andprogressive scan forward rotation at azimuths where dwell time is reduced compared to the default dwell time for the AESA;wherein the dynamic electronic azimuth beam steering is configured to maintain a substantially constant average target detection range as a function of azimuth in a presence of one or more non-uniform loss conditions that exist within at least a portion of the given search area; andwherein the rate of forward scan or back scan, at azimuth angles identified according to the azimuth offset profile, controls an amount of time spent transmitting within any given azimuth region and allows non-uniform distribution of radar energy as a function of azimuth, such that when the one or more non-uniform loss conditions are present, the non-uniform distribution of radar energy is configured to compensate for the non-uniform loss conditions to provide a substantially uniform probability of detection (Pd). 2. The AESA of claim 1, wherein the controller uses one or more templates, each respective template having respective durations that achieve a respective, pre-set azimuth spacing of search beams based on a mechanical rate and the azimuth offset profile. 3. The AESA of claim 2, wherein the controller uses a single template for all 360 degrees azimuth, the single template defining a first respective configuration for a first respective fan of search beams, wherein the single template comprises a first azimuth spacing of search beams, wherein the azimuth spacing increases and decreases proportional to the rate of forward and back scanning. 4. The AESA of claim 2, wherein the controller uses multiple templates, at least one of the multiple templates defining a second respective configuration for a second respective fan of search beams and wherein the second respective configuration comprises a second azimuth spacing of search beams, wherein the second respective configuration differs from the first respective configuration. 5. The AESA of claim 4, wherein the controller uses the multiple templates by using, during the progressive forward scan, a second progressive forward scan template having a second spacing that is a broader spacing than a first spacing associated with a first template and using, during a progressive backward scan, a higher energy template having the same spacing as the first spacing but having an energy level that is higher than a first energy level associated with the first spacing. 6. The AESA of claim 1, wherein the plurality of radiating elements is configured to operate in a predetermined first scan using a first pre-set spacing between search beams and having a first predetermined amount of beam overlap between search beams and wherein the controller uses, in the progressive forward scan, a broader spacing between search beams than used in the predetermined first scan and uses, in the progressive backward scan, a tighter spacing than used in the predetermined first scan, the tighter spacing comprising an amount of beam overlap that is greater than the first predetermined amount of beam overlap. 7. The AESA of claim 1, wherein the azimuth offset profile corresponds to operator-defined gain characteristics. 8. A method for providing dynamic azimuth scanning, the method comprising: determining gain improvements needed to at least partially compensate for locally increased azimuth regions of loss in a search area scanned by an antenna array, wherein the gain improvements are based on a first amount of energy of a radar beam from the antenna array, the first amount of energy generated when the antenna array is used at a first set of different azimuth angles of a 360° mechanical rotation of the antenna array, without the gain improvements, wherein the determined gain improvements are at least partially derived using information relating to locally increased azimuth regions of loss;providing dynamic electronic azimuth beam steering configured to vary a net azimuth beam scan rate, the dynamic electronic azimuth beam steering configured to: use multiple templates, the multiple templates comprising at least a first template and a second template, wherein the first template comprises a first respective spacing of search beams at a first energy level and the second template comprises a second respective spacing of search beams, the second respective spacing being a broader spacing than the first respective spacing;provide progressive scan back rotation at azimuths where dwell time is increased as compared to a default dwell time for the antenna array, wherein the progressive scan back rotation uses a higher energy template having the first spacing but having a third energy level that is higher than the first energy level associated with the first spacing; andprovide progressive scan forward rotation where dwell time is increased as compared to the default dwell time for the antenna array, to maintain a substantially constant average target detection range as a function of azimuth in a presence of non-uniform loss associated at least with the locally increased regions of loss, the progressive forward scan using the second template;generating a gain profile based on the determined gain improvements to identify gain to be applied at one or more azimuth angles of the first set of different azimuth angles of the 360° mechanical rotation; andderiving an azimuth offset profile using the gain profile, wherein the azimuth offset profile defines: a first subset of azimuth angles, associated with the locally increased azimuth regions of loss, the first subset comprising a first portion of the first set of different azimuth angles of the 360° mechanical rotation, where the antenna array is configured to use the progressive scan back in at least a portion of the locally increased azimuth regions of loss to provide additional energy to the radar beam, beyond the first amount of energy, to compensate for at least a portion of the locally increased azimuth regions of loss; anda second subset of azimuth angles corresponding to regions of low loss, the second subset comprising a second portion of the first set of different azimuth angles of the 360° mechanical rotation, wherein the antenna array is configured to use the progressive scan forward at the second subset of azimuth angles, the progressive scan forward configured to provide less energy to the radar beam, as compared with the first amount of energy. 9. The method of claim 8, wherein the deriving an azimuth offset profile further comprises: generating an initial azimuth offset profile;scaling the initial azimuth offset profile to ensure that a net electronic scan for a full rotation period of a radar that includes the antenna array is substantially zero by summing an amount of electronic scan in each sector and then applying a linear correction to the electronic scan in each sector to remove slope;biasing the scaled azimuth offset profile to ensure that the electronic scan is relative to a nominal electronic surveillance scan angle off azimuth broadside by subtracting a mean azimuth scan offset and adding the nominal surveillance azimuth angle; andscaling the biased azimuth offset profile such that a maximum cumulative electronic offset is capped at a predetermined value. 10. The method of claim 9 further comprising mapping the scaled, biased azimuth offset profile into a function of mechanical broadside azimuth angle for use in a radar scheduler as the radar rotates. 11. The method of claim 8, wherein the providing dynamic electronic azimuth beam steering further comprises using a single template for all 360 degrees azimuth, the single template defining a first respective configuration for a first respective fan of search beams and comprising a first azimuth spacing of search beams, wherein the azimuth spacing increases and decreases proportional to a rate of forward and back scanning. 12. The method of claim 8, wherein the antenna array is configured to operate with a predetermined first scan using a first pre-set spacing between search beams and wherein providing dynamic electronic azimuth beam steering further comprises using, in the progressive forward scan, a second spacing that is a broader spacing than the first pre-set spacing and using, in the progressive backward scan, a third spacing that is a tighter spacing than used in the predetermined first scan, the tighter spacing having more beam overlap than exists in the predetermined first scan. 13. The method of claim 8, wherein the providing dynamic electronic azimuth beam steering further comprises dynamic scanning providing a substantially uniform target range performance in a presence of non-uniform loss, wherein at least a portion of the locally increased azimuth regions of loss are is compensated for by allocating additional power to at least some of the radar beams directed to the locally increased azimuth regions of loss, wherein this additional power is provided by decreasing power provided to radar beams directed the azimuth regions that do not have substantial loss. 14. The method of claim 8, wherein determining gain improvements further comprises using weather survey measurements to estimate environmental losses as a function of azimuth angles by using a dedicated weather survey dwell template to detect and categorize rain at each azimuth angle. 15. At least one non-transitory machine readable medium comprising instructions that, when executed by the machine, cause the machine to perform operations for: determining gain improvements needed to at least partially compensate for locally increased azimuth regions of loss in a search area scanned by a radar, wherein the gain improvements are based on a first amount of energy of a radar beam from the radar, the first amount of energy generated when the radar beam is used at a first set of different azimuth angles of a 360° mechanical rotation of the radar, without gain improvements, wherein the determined gain improvements are at least partially derived from information relating to locally increased azimuth regions of loss;generating a gain profile based on the determined gain improvements to identify gain to be applied at one or more azimuth angles of the first set of different azimuth angles of the 360° mechanical rotation;deriving an azimuth offset profile using the gain profile, wherein the azimuth offset profile defines: a first subset of azimuth angles associated with the locally increased azimuth regions of loss, the first subset comprising a first portion of the first set of different azimuth angles of the 360° mechanical rotation, where progressive scan back is used in at least a portion of the locally increased azimuth regions of loss to provide additional energy to the radar beam, beyond the first amount of energy, to compensate for at least a portion of the locally increased azimuth regions of loss; anda second subset of azimuth angles, corresponding to regions of low loss, the second subset comprising a second portion of the first set of different azimuth angles of the 360° mechanical rotation, where progressive scan forward is used in the regions of low loss, the progressive scan forward configured to provide less energy to the radar beam as compared with the first amount of energyproviding dynamic electronic azimuth beam steering to vary a net azimuth beam scan rate, the dynamic electronic azimuth beam steering configured to: use multiple templates, the multiple templates comprising at least a first template and a second template, wherein the first template comprises a first respective spacing of search beams at a first energy level and the second template comprises a second respective spacing of search beams, the second respective spacing being a broader spacing than the first respective spacing;provide progressive scan back rotation at azimuths where extra dwell time is used as compared to a default dwell time for the radar, where the progressive scan back rotation uses a higher energy template having the first spacing but having a third energy level that is higher than the first energy level associated with the first spacing; andproviding progressive scan forward where reduced dwell time, as compared to the default dwell time for the radar, is allowed, to maintain a substantially constant average target detection range as a function of azimuth in a presence of non-uniform loss associated at least with the locally increased regions of loss, the progressive forward scan using the second template.