Click for next page ( 50


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 49
49 Additional Issues Certification In reviewing the current state of airport lightning detection While there are a large number of commercial lightning de- and warning systems, it was immediately evident that there tection systems available, it is difficult to evaluate them since are no common system standards, no certification or testing there is no certification process to assess their performance. procedures for lightning detectors, and no general agreement For relatively low cost systems that only signal when light- as to who should provide these warning services at U.S. airports. ning is near, comparison with lightning detection and position While we are not in a position to make recommendations in information from the NLDN should be adequate to evaluate these areas, they are important issues that limit our options and document each system's performance and limitations. for enhanced systems. Because these products are sold and advertised for the general consumer market, nonprofit organizations such as the Con- sumers Union might be willing to perform such tests. Who Should Provide Lightning Warning Performing an end-to-end evaluation of higher-end prod- Services? ucts with sophisticated warning algorithms and workstation At present, there is no general agreement as to who should displays would be more difficult. Unfortunately, these are the provide lightning warning services for airports. This is a dif- systems that are typically used at large airports. There has not ficult issue that hinges on the relative roles of the government been a comprehensive comparison of the relative accuracy and private industry and that is complicated by potential lia- and detection efficiency of the two competing national light- bility issues and the very significant cost of system installation ning detection networks. Performing such a test would require and maintenance. an independent detection capability to serve as ground-truth. In some cases, the largest or dominant airline at an airport In practice, validation studies have made use of photographic will purchase a system or contract for lightning warning serv- or video imagery from multiple viewing angles and by rocket ices, with the other carriers following their lead in deciding triggered lightning strikes. This means that validation testing when to clear the ramp, but occasionally making a contrary is a time-consuming, expensive effort, with each study con- decision on their own. In other cases, airports may maintain centrating on a single geographical area. A number of such warning systems for their own use, but not share their infor- validation tests have been published in the refereed literature mation with tenant airlines and other users. FAA and other for the NLDN (17, 18), but not for the USPLN. government agencies often have access to NLDN lightning Government laboratories such as the FAA's William data, sometimes on systems operated at the airport, but are J. Hughes Technical Center, NOAA Laboratories, and NOAA's prohibited by the terms of the government contract with university-based Cooperative Institutes could perform such the NLDN's commercial operator to make the data available tests, but these organizations are not general testing labora- for nongovernment use. The result is an often inefficient tories. They are government-funded organizations that do delivery of lightning warnings, with hit-or-miss application applied research in response to the needs of their sponsors. of safety measures and great potential for duplication of From a government perspective, there has not been a reason services. to provide certification or testing since the government has not purchased these systems to provide lightning detection and warning services. Standardization With different organizations providing lightning warning Looking Toward the Future services at different airports, it is not surprising that there is lit- Next Generation Air Transportation tle or no standardization of procedures or of shut down and System (NextGen) restart criteria. Individual operators make their own decisions, sometimes following their own established standards, and Planning is currently underway to modernize and upgrade other times responding to a supervisor's individual decision. the U.S. air transportation systems to meet the needs of the Standardization is generally the result of regulations and 21st century. The demand for air traffic services is expected mandatory procedures passed down from above or promul- to double or triple by 2025. Planning for the Next Generation gated by the agency providing the services. With no agreement Air Transportation System (NextGen) is the responsibility of as to who should provide these services, it is natural that there the Joint Planning and Development Office (JPDO), com- is no standardization to how the warnings are determined posed of representatives from the FAA, NASA, Department and what warning criteria are applied. A lack of standardiza- of Transportation, Department of Commerce, Department tion, however, permits individual operators to respond to of Defense (DoD), Department of Homeland Security, and their own needs and is often welcome. the White House Office of Science and Technology Policy.