Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
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Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc for Polarimetric Phase Array Radar Design)R. J. DoviakSummary: Matching the performances of the ARSR-4 and ASR-9/11 for aircraft detection and tracking, and that of the TDWR and the WSR-88D for weather surveillance, with a 10-cm wavelength Multi-function Phased Array Radar (MPAR; Stailey and Hondl, Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc 2016), or the Spectrum Efficient National Surveillance Radar (SENSR, 2017), using a 4-face Planar Polarimetric PAR (PPPAR) or a 4-sector CylindricalComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
Polarimetric PAR (CPPAR) is a challenging task. This memorandum is principally based on specifying the key requirements of an MPAR or SENSR if either 42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncficient surveillance radar, but specifications for SENSR include additional requirements that are not met by the existing network of surveillance radars. Whereas the MPAR is intended to be a cost-efficient single system of radars, the SENSR solution may be a system of systems.If a single beam per se Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncctor or face is used, the MPAR requires at least 8 kw (2 kw per 9(F sector or face—i.e., 2 kW for each of the four radars that comprise MPAR) of averaComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
ge power transmitted at 10-cm wavelength radiation propagating through precipitation described by the FAA model (Appendix 1, annotation 15c); 2 kw of 42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncired for the ARSR function of tracking aircraft at long ranges using 10 instead of 20-cm wavelength radiation. The remaining 1 kW of average power is needed for the ASR function and is that presently used for surveillance of aircraft near the airport. Thus using a single azimuthally scanned transmit Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc beam per sector and with a modest increase of average power (needed for the ARSR function), the volumetric update rates for aircraft surveillance areComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
12 s and 4.8 s respectively for the ARSR and ASR functions, which is that presently attained, but weather data can be collected twice as fast. To mee42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nce weather data collection mode (Appendix 1, annotation 16).Matching the 0.95' beamwidth of the WSR-88D, operating at a frequency of 2.7 GHz, sets the size of the MRAR (12.1 m diameter by 8.54 m tall for the CPPAR, and 4 faces each having an elliptical aperture 12.1 by 8.54 m for the PPPAR—an ellipti Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nccal aperture is needed to1meet the NWS’s requirement that the beamw idth should be 1° or less in all azimuth directions). The area of the active arrayComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
for each sector of the MPAR for weather is about the same as that for the ARSR-4. The total 325 nf active aperture area is the same for the 4-sector 42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc45° azimuths from broadside. But because the CPPAR forms its 1° beam by commutating, it has extra array elements in each of the four sectors —these extra elements can be utilized for sidelobe blanking and pattern synthesis (Zhang et al. 2011).The ARSR function of the 10-cm MPAR using 5 kW of average Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc power can meet the 20-cm ARSR-4 capability to detect and track aircraft at the longest range1 with precipitation if the ARSR-4 precipitation model spComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
ecified by the FAA (1988) for storm systems is used in computing propagation loss (Appendix 1, annotation 15c). But there can be more demanding precip42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc(annotation 10c) and Appendix 2. But these are relatively rare events that typically occur over central USA—higher average power would be required during these events if availability requirements are not met Appendix 1 (annotation 15d). However, increased power might not be necessary if all MPARS ha Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncve the same functionality because the MPAR coverage will blanket the continental US and there are likely other MPARs that can detect aircraft if echoeComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
s from one MPAR are not detected because of unusual excessive attenuation. Moreover because the MPAR might be a backup system to the upcoming GPS trac42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncw altitude wind shear along the approach and departure corridors of an airport, the 10-cm wavelength MPAR serving the ASR-9/11 function needs to be located closer, by a factor of two, to the airport than present TDWR sites or, perhaps better yet, located on the airport at or near the present site of Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc the ASR-9/11 (Cho, et al.. 2013).The most stringent antenna sidelobe level is set by the performance of the WSR-88D antenna (NWS, 2015). To match thiComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
s, it is recommended the specified MPAR two-way sidelobe level be below -64 dB at 2’ decreasing to -100 dB below the mainlobe gain at about 12’ and th42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nckely increase the incidence of data corrupted by sidelobe coupled power (Appendix 1, annotation 13).Furthermore, polarimetric H and V radiation patterns need to be well matched and to differ by less than 0.5 dB down to the -20 dB level below the peak of the mainlobe (Appendix 1 annotation 12).“Thank Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncs to William w. Shrader of Shrader Associates, Inc. for spotting an etror in computing ARSR-4 average power requirements that appeared in an earlier vComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
ersion.2IÍ lime multiplexing of the surveillance functions as described herein proves practical, and the transmitted pulse can be smoothly shaped, spe42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncce radars (Appendix 1. annotation 16).31.0 IntroductionThe University of Oklahoma (OU) with support from the National Severe Storms Laboratory (NSSL) is designing a CPPAR to demonstrate its capability not only for the multiplemissions of surveying weather and aircraft with a single type of radar, bu Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nct also to provide a platform for faculty and student research of weather, communications, aerobiology, etc. OU and NSSL are also testing a PPPAR demonComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
strator that has been designed and built by Lincoln Laboratory. This memo reviews the existing weather and aircraft surveillance radar capabilities th42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncnt radars, each at different locations, and operating in three different frequency bands. They are (Stailey and Hondl, 2016):1.) The FAA’s Airport Surveillance Radar (ASR-9/11) for the detection and tracking ofaircraft on the approach and departure around airports; 225 ASRs operate in the S-band (2. Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc7 to 3 GHz).2.) The FAA’s Terminal Doppler Weather Radar (TDWR) for the detection of low altitudewind shear along aircraft’s approach and departure coComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
rridors; 45 TDWRs operate in the C-band at approximately 5-cm wavelengths.3.) The NWS's Weather Surveillance Radar-1988 Doppler (WSR-88D) for detectio42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_nc parameters of precipitation; 156 WSR-88DS operate in the same band as the ASRs.4.) The Air Route Surveillance Radar (the Common ARSR and the ARSR-4) for the longrange surveillance of aircraft. The ARSR-4 radars are deployed mainly along the USA coast, and USA Islands (Healy et al., 1997). A seconda Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncry mission of the ARSRs is to detect and report weather within the coverage area. These radars are operated and maintained by the FAA, but serve bothComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
Homeland Security Functions (e.g., tracking aircraft crossing the borders of the USA), and Air Force defense goals; 79 CARSRs and 43 ARSR-4S operate i42989t\ Memorandum onComparisons of Weather and Aircraft Surveillance Radar Requirementsto Determine Key Features for a 10-cm MPAR and SENSR( A Basis Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncs—these also operate in the S-band.In summary there are about 629 radars deployed for surveillance of weather and/or aircraft at 629 sites. Because in densely populated areas there often are more than one nearby ASRs (e.g., NYC area has 3 major airports—LaGuardia, Kennedy, and Newark) some WSR and A Comparisons_of_weather_and_aircraft_surveillance_radar_6b_ncRSR functions might not be required at all 306 ASR sites. At those sites a smaller PAR could be deployed, or the WSR and ARSR functions can be kept inComparisons_of_weather_and_aircraft_surveillance_radar_6b_nc
a standby status if MPAR is deployed at all 306 ASR sites. There might be a few locations which need WSR and ARSR functions and there is no nearby ASGọi ngay
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