Publications
Enhanced radar data acquisition system and signal processing algorithms for the Terminal Doppler Weather Radar
October 24, 2005
Conference Paper
Published in:
32nd Conf. on Radar Meteorology, 24-29 October 2005.
Summary
As part of a broader FAA program to improve supportability, the Terminal Doppler Weather Radar (TDWR) radar data acquisition (RDA) subsystem is being replaced. For this purpose we developed an engineering prototype RDA with a scalable, open-systems hardware platform. This paper describes the design and characteristics of this new system. The dramatically increased computing power and more flexible transmitter control also enables modern signal processing algorithms to be implemented to improve the quality of the base data. Results highlighting the improved range-overlay protection provided by the new algorithms are presented.
Summary
As part of a broader FAA program to improve supportability, the Terminal Doppler Weather Radar (TDWR) radar data acquisition (RDA) subsystem is being replaced. For this purpose we developed an engineering prototype RDA with a scalable, open-systems hardware platform. This paper describes the design and characteristics of this new system...
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Improved range-velocity ambiguity mitigation for the Terminal Doppler Weather Radar
October 4, 2004
Conference Paper
Published in:
11th Conf. on Aviation, Range and Aerospace Meteorology, 4-8 October 2004.
Summary
The Terminal Doppler Weather Radar (TDWR) radar data acquisition (RDA) subsystem is being replaced as part of a broader FAA program to improve the supportability of the system. An engineering prototype RDA has been developed with a scalable, open-systems hardware platform. With the dramatically increased computing power and more flexible transmitter control, modern signal processing algorithms can be implemented to improve the quality of the base data. Nation-wide, the most serious data quality challenge is range-velocity (RV) ambiguity. In a previous study (Cho et al., 2003) we showed that multiple pulse repetition interval (PRI) and constant-PRI phase-code processing have complementary strengths with respect to range-fold protection, and pro-posed an adaptive waveform and processing selection scheme on a radial-by-radial basis. Here we describe the scheme and give more details about the clutter filtering and velocity dealiasing algorithms to be used on the two types of signals.
Summary
The Terminal Doppler Weather Radar (TDWR) radar data acquisition (RDA) subsystem is being replaced as part of a broader FAA program to improve the supportability of the system. An engineering prototype RDA has been developed with a scalable, open-systems hardware platform. With the dramatically increased computing power and more flexible...
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Range-velocity ambiguity mitigation schemes for the enhanced Terminal Doppler Weather Radar
August 6, 2003
Conference Paper
Published in:
37th Int. Conf. on Radar Meteorology, 6-12 August 2003.
Summary
The Terminal Doppler Weather Radar (TDWR) radar data acquisition (RDA) subsystem is being replaced as part of a broader FAA program to improve the supportability of the system. An engineering prototype RDA is under development that will provide a modern, open-systems hardware platform and standards-compliant software. The new platform also provides an opportunity to insert algorithms to improve the quality of existing base data products, as well as support future enhancements to the aviation weather services provided by TDWR. There are several outstanding data quality issues with the TDWR. In this paper, we focus on mitigation schemes for the range-velocity ambiguity problem that is especially severe for C-band weather radars such as the TDWR.
Summary
The Terminal Doppler Weather Radar (TDWR) radar data acquisition (RDA) subsystem is being replaced as part of a broader FAA program to improve the supportability of the system. An engineering prototype RDA is under development that will provide a modern, open-systems hardware platform and standards-compliant software. The new platform also...
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Enhancement to Terminal Doppler Weather Radar to improve aviation weather services
May 13, 2002
Conference Paper
Published in:
10th Conf. on Aviation, Range, and Aerospace Meteorology, 13-16 May 2002, pp. 28-31.
Topic:
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Summary
This paper has described work underway to enhance the TDWRs capability to provide wind shear detection services in challenging conditions, and to provide a flexible platform with COTS hardware that would support future improvements. A Radar Data Acquisition (RDA) system retrofit will upgrade the transmitter, receiver and digital signal processing subsystems of the radar to improve the quality of the reflectivity and Doppler imagery generated by the system and to extend its instrumented range. Algorithms have been described for achieving improved rejection of ground clutter and range-folded weather echoes, and reduction of Doppler velocity aliasing. An open COTS-based processing architecture was presented for the TDWR RDA retrofit, and a test program was outlined that is commencing in Oklahoma in the spring of 2002.
Summary
This paper has described work underway to enhance the TDWRs capability to provide wind shear detection services in challenging conditions, and to provide a flexible platform with COTS hardware that would support future improvements. A Radar Data Acquisition (RDA) system retrofit will upgrade the transmitter, receiver and digital signal processing...
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The radar Correlation and Interpolation (C&I) algorithms deployed in the ASR-9 Processor Augmentation Card (9PAC)
June 29, 2001
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-299
Topic:
R&D area:
R&D group:
Summary
The Airport Surveillance Radar 9 (ASR-9) is a terminal radar that was deployed by the Federal Aviation Administration (FAA) during the early 1990's at more than 130 of the busiest airports in the United States. The ASR-9 Processor Augmentation Card (9-PAC), developed at MIT Lincoln Laboratory, is a processor board enhancement for the ASR-9 Array Signal Processor (ASP) that provides increases in processing speed, memory size, and programming. The increased capabilities of the 9PAC hardware made it possible for new surveillance algorithms to be developed in software to provide improved primary radar and beacon surveillance performance. The 9PAC project was developed in two phases. Phase I, which addressed the beacon reflection false target problem, was completed, and is currently being deployed nationwide by the FAA on a plug and play basis. Phase II addresses the primary radar surveillance problems, which include automation of the road and ground clutter censoring process, improving the rejection of false targets, and improving the detection and tracking of aircraft targets. The 9PAC also reduces the life-cycle maintenance cost of the ASR-9 in the Phase II configuration, in which a single 9PAC card replaces four ASP cards. This report describes the improvements to the radar Correlation and Interpolation (C&I) process, which is responsible for creating aircraft target reports and filtering out false targets. [Not Complete]
Summary
The Airport Surveillance Radar 9 (ASR-9) is a terminal radar that was deployed by the Federal Aviation Administration (FAA) during the early 1990's at more than 130 of the busiest airports in the United States. The ASR-9 Processor Augmentation Card (9-PAC), developed at MIT Lincoln Laboratory, is a processor board...
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The Beacon Target Detector (BTD) algorithms deployed in the ASR-9 Processor Augmentation Card (9-PAC)
September 5, 2000
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-288
Summary
This project report describes the Beacon Target Detector (BTD) algorithms implemented in the ASR-9 Processor Augmentation Card (9-PAC). The BTD function combines replies that arise from the same aircraft to form beacon targets, and sends these beacon targets to the 9-PAC merge process where they are combined with primary radar targets. The 9-PAC BTD algorithm was designed to solve two problems with the ASR-9 Array Signal Processor (ASP) BTD: identifying and removing false beacon targets due to reflections, and preventing merging or splitting of targets due to reply overlap and garble. The BTD reflection processing algorithm marks each beacon target as either real or false, and provides this information to the 9-PAC merge process. Discrete Mode 3/A reflection false targets are identified when duplicate code reports satisfying stringent conditions are located. In order to find non-discrete Mode 3/A code reflection false targets, the BTD builds an automated, dynamic reflector database based on the geography of real and false targets with discrete Mode 3/A codes. This report supersedes an earlier report (ATC-220) which described the 9-PAC BTD algorithms prior to the operational field testing effort conducted by the FAA in 1995 and 1996. Nationwide deployment of 9-PAC on production hardware was approved in April 1999. To date, more than 60 installations have been performed, and hardware has been procured to update all 134 ASR-9s in the National Airspace System.
Summary
This project report describes the Beacon Target Detector (BTD) algorithms implemented in the ASR-9 Processor Augmentation Card (9-PAC). The BTD function combines replies that arise from the same aircraft to form beacon targets, and sends these beacon targets to the 9-PAC merge process where they are combined with primary radar...
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A 9PAC system and application programmer's guide
February 16, 1999
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-267
Topic:
R&D area:
Summary
The ASR-9 Processor Augmentation Card (9PAC) is a custom processing card that provides the ASR-9 system with increased beacon and radar processing performance. This paper describes the system and application software that executes on the prototype board, with an emphasis on the interaction between software modules. The application software on the 9PAC determines the position of radar and beacon target reports, replacing software that previously ran on the ASR-9 Array Signal Processor (ASP). The software is organized as a set of cooperating tasks executing under the control of a real-time operating system, PAC/OS, which provides all the services typical of an embedded kernel such as interrupt handling, pre-emptive multitasking, queues, signals, semaphores, mailboxes, and memory management. The deployment of 9PAC will occur in two phases. The Phase I application replaces only the beacon target detector (BTD) and radar/beacon target merge (MRG) functions of the ASP. The Phase I application consists of two executable programs since Phase I uses only two of the C44 processors on the 9PAC. One program, the housekeeping processor, is responsible for all I/O functions and performs the radar/beacon merge operation. The second progam, the beacon processor, is dedicated to processing the raw beacon replies and generating beacon targets which are then returned to the first processor for the merge operation. The Phase II application consists of three executable programs, one for each of the C44 processors on the 9PAC and performs much of the Phase I functionality and adds primary radar processing. The intent of this paper is to provide the 9PAC software support personnel with sufficient information to implement future enhancements without unintentionally compromising some aspect of the overall system.
Summary
The ASR-9 Processor Augmentation Card (9PAC) is a custom processing card that provides the ASR-9 system with increased beacon and radar processing performance. This paper describes the system and application software that executes on the prototype board, with an emphasis on the interaction between software modules. The application software on...
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Documentation of 9-PAC Beacon Target Detector processing function
July 26, 1994
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-220
Summary
This project report documents the algorithms and flow of the Beacon Target Detector (BTD) processing function incorporated as part of the ASR-9 Processor Augmentation Card (9-PAC). The BTD function combines replies that arise from the same aircraft to form beacon targets, and sends these beacon targets to the 9-PAC merge process where they are combined with primary radar reports. The 9-PAC BTD process was designed to solve two problems with the ASR-9 Array Signal Processor (ASP) BTD: identifying and removing false beacon targets due to reflections, and preventing merging or splitting of targets due to reply overlap and garble. The BTD reflection processing algorithm marks each beacon target as either real or false, and provides this information to the 9-PAC merge process. Discrete Mode A reflection false targets are identified when duplicate code reports satisfying stringent conditions are located. In order to find non-discrete Mode A code reflection false targets, the BTD builds an automated, dynamic reflector database based on the geography of pairs of discrete real and false targets.
Summary
This project report documents the algorithms and flow of the Beacon Target Detector (BTD) processing function incorporated as part of the ASR-9 Processor Augmentation Card (9-PAC). The BTD function combines replies that arise from the same aircraft to form beacon targets, and sends these beacon targets to the 9-PAC merge...
READ MORE