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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <title>Predicting the Health Status of an Unmanned Aerial Vehicles Data-Link System Based on a Bayesian Network</title>
      <link>https://trid.trb.org/View/1569770</link>
      <description><![CDATA[Unmanned aerial vehicles (UAVs) require data-link system to link ground data terminals to the real-time controls of each UAV. Consequently, the ability to predict the health status of a UAV data-link system is vital for safe and efficient operations. The performance of a UAV data-link system is affected by the health status of both the hardware and UAV data-links. This paper proposes a method for predicting the health state of a UAV data-link system based on a Bayesian network fusion of information about potential hardware device failures and link failures. The authors' model employs the Bayesian network to describe the information and uncertainty associated with a complex multi-level system. To predict the health status of the UAV data-link, the authors use the health status information about the root node equipment with various life characteristics along with the health status of the links as affected by the bit error rate. In order to test the validity of the model, the authors tested its prediction of the health of a multi-level solar-powered unmanned aerial vehicle data-link system and the result shows that the method can quantitatively predict the health status of the solar-powered UAV data-link system. The results can provide guidance for improving the reliability of UAV data-link system and lay a foundation for predicting the health status of a UAV data-link system accurately.]]></description>
      <pubDate>Thu, 20 Dec 2018 15:32:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1569770</guid>
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    <item>
      <title>A Near-Term Concept for Trajectory Based Operations with Air/Ground Data Link Communication</title>
      <link>https://trid.trb.org/View/1122858</link>
      <description><![CDATA[An operating concept and required system components for trajectory-based operations with air/ground data link for today's en route and transition airspace is proposed. Controllers are fully responsible for separation as they are today, and no new aircraft equipage is required. Trajectory automation computes integrated solutions to problems like metering, weather avoidance, traffic conflicts and the desire to find and fly more time/fuel efficient flight trajectories. A common ground-based system supports all levels of aircraft equipage and performance including those equipped and not equipped for data link. User interface functions for the radar controller's display make trajectory-based clearance advisories easy to visualize, modify if necessary, and implement. Laboratory simulations (without human operators) were conducted to test integrated operation of selected system components with uncertainty modeling. Results are based on 102 hours of Fort Worth Center traffic recordings involving over 37,000 individual flights. The presence of uncertainty had a marginal effect (5%) on minimum-delay conflict resolution performance, and wind-favorable routes had no effect on detection and resolution metrics. Flight plan amendments and clearances were substantially reduced compared to today's operations. Top-of-descent prediction errors are the largest cause of failure indicating that better descent predictions are needed to reliably achieve fuel-efficient descent profiles in medium to heavy traffic. Improved conflict detections for climbing flights could enable substantially more continuous climbs to cruise altitude. Unlike today's conflict alert, tactical automation must alert when an altitude amendment is entered, but before the aircraft starts the maneuver. In every other failure case, tactical automation prevented losses of separation. A real-time prototype trajectory automation system is running now and could be made ready for operational testing at an enroute center in 1-2 years.]]></description>
      <pubDate>Tue, 29 Nov 2011 13:43:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1122858</guid>
    </item>
    <item>
      <title>Linking Emergency Medical Department and Road Traffic Police Casualty Data: A Tool in Assessing the Burden of Injuries in Less Resourced Countries</title>
      <link>https://trid.trb.org/View/885748</link>
      <description><![CDATA[The study aimed to (1) assess the magnitude of road traffic injuries in a country missing a formal linkage system of police with hospital data, (2) quantify the underreporting, and (3) produce a convenient algorithm exploring its constituent components. Linkage of disaggregate (individual) data collected by the road traffic police (RTP) with those by the Emergency Department Injury Surveillance System (EDISS) on the Greek island of Corfu and coded with different classification systems was carried out. The applied four-step methodology, also comprising the calculation of underreporting coefficients of the variation by basic demographic variables, mode of transport, and injury outcome, led to the identification of the overall underreporting from either registry. RTP data captured 96.6% (coefficient: 1.035), whereas EDISS captured only 54.4% of total fatalities (overall concordance: 51.1%). On the contrary, EDISS captured 94.6% of nonfatal injuries, whereas RTP only captured 16% (coefficient: 6.238), resulting in a low overall concordance (10.6%). Considering severity of injury assessed by EDISS, by using the ISS as the gold standard, RTP data misclassified 20.3% of severe injuries as less severe, and a statistically significant difference in the underreporting by gender was also noted. Relatively simple methodologies can provide essential coefficients to assess the actual numbers, severity, and components of road casualties by complementing routinely collected RTP with sentinel emergency department reporting systems.]]></description>
      <pubDate>Fri, 27 Mar 2009 10:45:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/885748</guid>
    </item>
    <item>
      <title>DISCRETE ADDRESS BEACON SYSTEM DATA LINK CAPACITY REQUIREMENTS</title>
      <link>https://trid.trb.org/View/170492</link>
      <description><![CDATA[The Federal Aviation Administration plans to deploy the Discrete Address Beacon System (DABS) as a key feature of its upgraded third generation Air Traffic Control System. DABS provides an integral data link capable of conducting rapid transfer of data between the sensor and DABS equipped aircraft. This study establishes the performance requirements of the DABS data link to be able to provide the various services that may reasonably be expected to be delivered by DABS during its life time.]]></description>
      <pubDate>Tue, 28 Oct 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/170492</guid>
    </item>
    <item>
      <title>PROCEEDINGS OF THE PUBLIC WORKSHOP ON ALTERNATIVE SEPARATION CONCEPTS: PRESENTATIONS, DISCUSSIONS AND RECOMMENDATIONS, HELD AT ATLANTIC CITY AIRPORT, NEW JERSEY, JANUARY 7, 8 AND 9, 1981</title>
      <link>https://trid.trb.org/View/170530</link>
      <description><![CDATA[This report documents the proceedings of a Federal Aviation Administration (FAA) public workshop on Alternative Separation Concepts during January 7-9, 1981. The first day was devoted to presentations describing FAA/NASA ongoing programs to improve the ATC system with an emphasis on those aspects which would directly improve the services offered to pilots. These improvements would primarily ease the entry into and exit from the IFR system, and the accommodation of pilot preferred routings. The second and part of the third day were devoted to participant discussions which are unrecorded. There were three working groups, technical, procedural and economic which reported their recommendations at the close of the workshop. The participants at the workshop did not identify a fundamentally new concept for air traffic control. They concluded that it would be desirable to continue development of existing and planned Secondary Surveillance Radar-based systems. The promising approaches to system improvements to permit a greater degree of freedom of GA operations were classified by the availability of surveillance services. Within ground-based surveillance coverage, and automatic ground-based primary separation service was the recommended approach. Outside of surveillance coverage, an airborne-based primary separation service utilizing the signal format of the improved secondary surveillance radar system was recommended for further development. (Author)]]></description>
      <pubDate>Tue, 28 Oct 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/170530</guid>
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    <item>
      <title>FAA COMMUNICATIONS COST MODEL USER'S GUIDE. REVISED</title>
      <link>https://trid.trb.org/View/155869</link>
      <description><![CDATA[The FAA Communications Cost Model User's Guide provides information regarding applications, requirements, and operation of the model, describes user input data and procedures for setting up a run, and gives a sample problem showing how each data card is set up. Appendixes provide facilities and equipment (F&E) and operations and maintenance (O&M) parameters assumed in the model and describe each output report.]]></description>
      <pubDate>Mon, 27 Oct 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/155869</guid>
    </item>
    <item>
      <title>COMMUNICATIONS SUPPORT FOR AREA A AND REQUEST/REPLY</title>
      <link>https://trid.trb.org/View/170321</link>
      <description><![CDATA[Service A communication requirements were analyzed to determine the optimal communications support strategy, with the National Airspace Data Interchange Network (NADIN) integration as one of the primary alternatives to be evaluated. That analysis yielded the following conclusions: integration of Service A into NADIN will reduce monthly leased line recurring costs; NADIN use will result in little or no increase in total present value cost; Service A integration into NADIN is not feasible prior to WMSC replacement; WMSC Replacement design will be simplified by use of NADIN support for Service A; and NADIN will improve Service A performance by permitting cost effective circuit reconfiguration. In addition, the analysis determined detailed enhancements to NADIN required to support Service A while adequately maintaining other NADIN traffic.]]></description>
      <pubDate>Tue, 16 Sep 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/170321</guid>
    </item>
    <item>
      <title>INTERFACE DEFINITION DABS ENGINEERING MODEL/ATC (NAFEC). DIGITAL SIMULATION FACILITY DATA FORMATS. VOLUME II. SERIES 3</title>
      <link>https://trid.trb.org/View/42526</link>
      <description><![CDATA[This document describes the formats of the simulated surveillance and communications messages for the interface between the Digital Simulation Facility (DSF) and the Air Traffic Control (ATC) facilities at NAFEC. The facilities which will be interfaced with the DSF are the NAS Enroute System in the System Support Facility (SSF) and the ARTS 3 System in the Terminal Automation Test Facility (TATF). These interfaces will be made available for use for IPC Phase 2 testing and other advanced ATC system test activities requiring the simulation of the Discrete Address Beacon System in the DSF. (Author)]]></description>
      <pubDate>Sun, 13 Jul 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/42526</guid>
    </item>
    <item>
      <title>INTERFACE DEFINITION DABS ENGINEERING MODEL/ATC (NAFEC). TERMINAL HARDWARE CONFIGURATION. VOLUME IV</title>
      <link>https://trid.trb.org/View/42527</link>
      <description><![CDATA[This document describes the hardware interfaces required between the Discrete Address Beacon System (DABS) Engineering Models, to be installed at or near the National Aviation Facilities Experimental Center (NAFEC), and the Terminal Automation Test Facility (TATF) at NAFEC. This interface will be used to support DABS development tests and the Upgraded Third Generation System Tests including the Intermittent Positive Control (IPC) Phase II tests. (Author)]]></description>
      <pubDate>Sun, 13 Jul 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/42527</guid>
    </item>
    <item>
      <title>FLIGHT TESTS OF DIGITAL DATA TRANSMISSION AT VHF</title>
      <link>https://trid.trb.org/View/41495</link>
      <description><![CDATA[This report describes the results of a series of 11 experimental flights which measured the characteristics of air-to-ground digital transmission in the VHF aeronautical mobile frequency band. The tests were conducted for the Federal Aviation Administration at National Aviation Facilities Experimental Center in Atlantic City, NJ. Digital transmission rates of 2400 and 4800 bps were used with minimum-shift-keying (MSK) as the baseband modulation format. The MSK signal was transmitted on a test frequency of 120.85 MHz using conventional, air/ground voice communication equipment. A number of parameters were measured during the flights and an extensive decription is given of the bit error rates which were encountered. Received signal level was also monitored, and data describing average signal level and signal fading are presented. Other parameters measured were clock slips, carrier lossess, distribution of errors, and signal fading caused by aircraft maneuvering. The tests show that digital transmission rates of 2400 and 4800 bps can be supported, with existing FAA and ARINC equipment, at an average bit error rate near 0.00005. (Author)]]></description>
      <pubDate>Sun, 13 Jul 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/41495</guid>
    </item>
    <item>
      <title>NUMERICAL SIMULATION OF WIND FIELDS CALCULATED FROM ASSUMED MODE S DATA LINK INPUTS</title>
      <link>https://trid.trb.org/View/177162</link>
      <description><![CDATA[The future availability of the Mode S data link has suggested the possibility of using data collected by airplanes flying in the airport environment to reconstruct the atmospheric wind field in the airport area. These reconstructed fields would conceivably be of use to the metering and spacing personnel as well as to meteorologists and pilots flying through this particular atmospheric environment. An investigation was conducted to determine the feasibility of using a numerical method developed by J. T. Schaefer and C. A. Doswell III to produce an objectively analyzed wind field from sparse aircraft observations. A theoretical wind field resembling atmospheric conditions was used to compare the predicted field with the assumed theoretical field. Also investigated were (1) the degradation of the technique produced by decreasing the number of observations and (2) the influence of wind wavelength in the accuracy of the wind field prediction.]]></description>
      <pubDate>Mon, 30 Jun 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/177162</guid>
    </item>
    <item>
      <title>AN UPDATE OF THE DISCRETE ADDRESS BEACON SYSTEM (DABS) ALTERNATIVES STUDY</title>
      <link>https://trid.trb.org/View/162929</link>
      <description><![CDATA[This document is an update of an earlier 'Study of Alternative Beacon Based Surveillance and Data Link Systems.' It is based on the numerous studies, analyses, simulations, and flight tests conducted since the original study. The document uses the findings from that large body of work to summarize the rationale that led to the selection and continued development of DABS + ATARS + BCAS as the preferred approach to improving the surveillance, air-ground communications, and the collision avoidance functions of the ATC system and provide the basis for further improvements in the automation of the ATC system. Hypothetical scenarios heavily weighted in favor of the most competitive alternative, SAB + VHF D/L + ATARS, are presented as a basis for cost comparisons. DABS + ATARS + BCAS is shown to be the most cost effective approach.]]></description>
      <pubDate>Thu, 12 Jun 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/162929</guid>
    </item>
    <item>
      <title>COMMUNICATIONS SUPPORT FOR NATIONAL FLIGHT DATA CENTER INFORMATION SYSTEM</title>
      <link>https://trid.trb.org/View/162748</link>
      <description><![CDATA[The National Flight Data Center/Information System (NFDC/IS) data communications requirements were analyzed to determine the technical feasibility and the most cost beneficial approach of NADIN support. The following conclusions were made: The most cost/beneficial approach to NADIN support of the NFDC/IS data communications requirements provides for the use of NADIN for interactive and message traffic and dedicated facilities for the point-to-point, source-to-sink batch traffic. The most significant aspect of NADIN support for the NFDC/IS data communications requirements is in providing the communications link between the NFDC host system and the external systems with which it must interface. (Author)]]></description>
      <pubDate>Tue, 15 Apr 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/162748</guid>
    </item>
    <item>
      <title>ENGINEERING ANALYSES OF CANDIDATE COMMUNICATION AND SURVEILLANCE TECHNIQUES FOR THE VESSEL TRAFFIC SYSTEM</title>
      <link>https://trid.trb.org/View/171703</link>
      <description><![CDATA[Coast Guard Vessel Traffic Service (VTS) facilities rely heavily on radio communications to acquire the location of vessels and disseminate this information to other interested shipping. As the communication requirements change, the Coast Guard must be knowledgeable of the options available to meet the new requirements. To provide a basis for future system expansion and design, this study explores the commmunication channels available to maritime mobile service and the impact of change from voice to voice/data and data/only communication. Analysis under Task I reviews all frequency bands available for maritime service, identifying for each band all permissable transmission methods. Task II considers three candidate systems. The performance of these systems was analyzed with respect to present and future communications requirements using statistical VTS communication data. The systems are described with respect to hardware requirements and are characterized by the attainable data transmission rate. Cost estimates are furnished for all equipment not normally carried on commercial seagoing vessels, as well as the cost of modifying existing equipment. As a result of this study, the following conclusions are stated: (1) The introduction of a voice-based periodic position reporting scheme will quickly saturate available communication channels; and (2) There are digital communication systems capable of expanding the capacity of existing communication channels.]]></description>
      <pubDate>Sun, 30 Mar 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/171703</guid>
    </item>
    <item>
      <title>AUTOMATIC TRAFFIC ADVISORY AND RESOLUTION SERVICE (ATARS) ALGORITHMS INCLUDING RESOLUTION-ADVISORY-REGISTER LOGIC. VOLUME 1. SECTIONS 1 THROUGH 11</title>
      <link>https://trid.trb.org/View/171296</link>
      <description><![CDATA[This document presents detailed computer algorithms for programming the Automatic Traffic Advisory and Resolution Service (ATARS). A major feature of this version of the ATARS algorithms is the capability to exchange resolution advisory information via the airborne Resolution Advisory Register (RAR). This provides for coordination of resolution advisories between ATARS and airborne collision avoidance systems and between adjacent ATARS sites in the absence of ground communication lines. The ground based ATARS computers use the surveillance data from the Discrete Address Beacon System (DABS) to provide properly equipped aircraft with traffic advisories and collision resolution advisories. These advisories are discretely delivered to the aircraft via the DABS data link. The ATARS algorithms are presented in two volumes rather than one large document in order to provide the algorithms in a more manageable form.]]></description>
      <pubDate>Wed, 29 Jan 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/171296</guid>
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