Quotes Of The Quarter
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"We are on schedule for full double coverage by 2003. The requirement is for less than 10 meters; you can expect 2-to-3 meters" in accuracy. John Macaluso, DoT, on the Nationwide Differential GPS system (NDGPS) being installed by the U.S. Coast Guard.
"The provision of a second and third civil frequency
can provide ionospheric delay estimation, redundancy to protect against
unwanted interference, improved carrier phase ambiguity removal, and improved
tracking accuracy with or without multipath." Dr. James Spilker, Stanford
Telecom, on his proposal for split spectrum civil signals for GPS.
Nominations Open for ION Annual Awards
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Members are encouraged to submit their nominations now for one or more of the prestigious Annual Awards given by the ION for excellence in navigation. The Early Achievement Award for a student in navigation, established for the first time last year, is again a part of the nomination process this year. The awards are:
Official nomination forms, along with brochures on the background and purpose of each award, are available by calling the ION national office, 703-683-7101 or e-mail: membership@ion.org. Nominations must be received by February 23, 1999.
The awards and accompanying engraved bronze plaques will be presented at ION's 55th Annual Meeting, June 28-30, 1999 in Cambridge, Massachusetts. ION urges you to participate in the nomination process so that a representative group of deserving individuals from the navigation community will receive appropriate recognition.
In addition to the five above awards, the winner of the
Samuel M. Burka Award-for outstanding achievement in the preparation of
papers advancing navigation and space guidance- chosen by the editorial
panel of ION's quarterly journal, NAVIGATION, will be similarly honored
during the awards ceremony.
Committee Votes to Expand GPS Meeting
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The Satellite Division Executive Committee has approved plans to expand the program for future ION GPS annual meetings to include a fifth track devoted to application-oriented presentations. The fifth track, or main topic around which daily sessions are arranged, will be initiated as part of ION GPS-99, to be held again in Nashville next September.
The action, part of a number of revisions and reforms for improvements in the future, came at a meeting of the Committee during the ION GPS-98 meeting in Nashville last September. The Committee also approved a change in the process of selecting winning student papers.
Under the present system, student papers are selected by organizers, then later given to Session Chairs to "plug into" their individual sessions, sometimes necessitating that Chairs "bump" a speaker. In the future, Session Chairs will select the winners among student papers. Students will be required to submit completed papers at the same time that abstracts are due, and choose the sessions where their papers should be presented. Abstracts for ION GPS-99 are due March 19.
The Committee discussed progress on a division-sponsored history of GPS aimed at documenting the origins of GPS, and helping persons to update themselves on the technology and applications of GPS; approved a motion to increase base registration fees by $25; voted to allow adjustments in exhibit space costs for publishing companies; permit past tutorial providers to apply for multiyear contracts of up to three years, and approved a budget for continued support on the issue of GPS/GLONASS interoperability.
The Committee reviewed plans for future meeting sites:
Nashville 1999, Salt Lake City 2000-2001, and possible sites for 2002-03
among these candidate cities - Ft. Worth, Charleston, SC, Portland, OR and
Reno, NV.
ION Fellows: First-Time Nominations Solicited
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Nominations should be submitted now for the newly created honors of Fellow and Honorary Fellow of the ION. Nominations are due before January 4, 1999.
A Fellow is a currently active ION member who has made distinguished contributions to the advancement of technology, management, practice, or teaching of the arts and sciences of navigation, and/or for lifetime contributions to the Institute. Posthumous citations are authorized. An Honorary Fellow is a non-member of the ION, meeting the same criteria for election as a Fellow and who is, preferably, a member of some national institute of navigation.
Information about the Fellows Programs and a recommendation form for nominations are posted on ION's Web page at www.ion.org. Please submit your recommendations to ION to either of the following addresses:
E-mail to cmayes@ion.org, or facsimile to 703-683-7105.
Richard Greenspan is Chair of the Fellow Nominating Committee.
FAA Completes Successful WAAS Flight Trials
in the Republic of Chile The Federal Aviation Administration (FAA) and the Republic of Chile's Director General of Civil Aeronautics (DGAC) successfully completed the first test flights in Chile demonstrating the capabilities and benefits of the Wide Area Augmentation System (WAAS). The test flights were conducted at the Arturo Merino Benitez International Airport in Santiago, Chile, on Dec. 9. This effort represented the latest step towards achieving a seamless, worldwide satellite-based air navigation system. "These successful flight trials achieved another major step toward the establishment of a safer and more dependable satellite-based air navigation system for North and South America," said FAA Administrator Jane F. Garvey. Reference stations in Santiago, Balmaceda, and Antofagasta were installed this fall and connected to the FAA-developed National Satellite Test Bed master station in Atlantic City, N.J. via a combination of satellite and terrestrial communications. For this demonstration, an FAA Boeing 727 aircraft conducted a series of Category I precision approaches (down to approximately 200 feet) using a navigation signal generated and broadcast by the Test Bed. The Test Bed, in use since 1991, has routinely demonstrated navigation accuracy (horizontal and vertical) well within the Category I precision approach requirements to both national and international audiences. These tests will help international aviation authorities make the transition from current ground-based navigation technologies to satellite-based navigation using GPS/WAAS as the cornerstone technologies. One of the highlights of this WAAS demonstration was to showcase the flexibility of satellite navigation technology for tailored or unique precision approaches in situations where current ground-based precision approach technologies are limited. The Arturo Merino Benitez International Airport is surrounded by the Andes Mountain range and requires very flexible and precise navigation systems. Preliminary analyses indicate that the horizontal and vertical accuracies for all flights were approximately 3-4 meters, well under the 7.6 meters required for Category I precision approaches. |
Inmarsat has agreed on plans to turn the 84-nation international cooperative that operates a global mobile satellite system into a private company next year on April 1. It will issue stock in an initial public offering within two years thereafter. The new company will remain in London, and will be governed by a 15-member Board. Under a two-tier structure, Inmarsat also will continue to meet its public responsibilities, including distress and safety communications, under an intergovernmental secretariat.
Small particles from meteor showers that potentially can damage in-orbit satellites such as those in the GPS constellation have long been observed and monitored. Now, NASA's Jet Propulsion Laboratory in Pasadena is establishing the Near-Earth Object Program Office to locate and track asteroids and comets larger than 1 km. in diameter that can cause "global effects" if they strike Earth.
A FAA 727 successfully performed a series of Cat I precision approaches at Iceland's Keflavik Airport in October, using signals from both U.S. and European GPS-based Wide Area Augmentation System (WAAS) testbeds. The flight tests were the latest step in developing a seamless, space-dependent navigation system for worldwide aviation use.
Rare books, historic navigation instruments and other valuable period items collected by the late Mary Tornich Janislawski (see News in Brief last issue) have been graciously offered to the ION by the deceased's daughter, Mimi Janislawski, for an ION museum of the future.
Michael Baker Corp., an engineering, construction and technical services company in Pittsburgh, has acquired GeoResearch Corp. of Maryland to expand its business into GPS-based markets such as mapping and vehicle fleet management.
Differential GPS signals transmitted
to a Pershing 2 missile refined the missile's flight path to produce a circular
error probable of less than 5 meters at the target site, according to Air
Force personnel who conducted tests at the White Sands Missile Range. It
was the first time a reentry vehicle received correction data in flight
that successfully altered it direction. The technique could utilize a wide
area GPS network to improve long-range ballistic and cruise missile accuracies
in the future.
Congress appropriated $7 million for Loran-C upgrades in the current
fiscal year (FY1999), and authorized $35 million for Loran next year, FY2000.
Loran supporters expect DoT to formally announce in February an extension
of Loran's lifetime to 2008, countering current federal policy to terminate
it at the end of 2000.
IBM will produce GPS chips for Leica using its new silicon germanium technology that is expected to result in chips with higher speed at lower power consumption than conventional gallium arsenide processes. Leica will provide the chip designs. The move by IBM is seen as its effort to become a leading supplier of high-volume, low-cost chip sets in the GPS market.
Department of Commerce study forecasts that the worldwide market for GPS products will grow at an average rate of about 25 percent during the period 1998-2003. The study, GPS Markets: Market projections and Trends in the Newest Global Information Utility, estimates global sales of GPS products will reach $8 billion by 2000, and could exceed $16 billion by 2003.
ION Award given to Sam Ryan, for graduate student (The University of Calgary) with the highest contribution to navigation as judged by research and publications.
Chile has completed installation of two WAAS-type test bed reference stations in Santiago and Balmaceda to determine the feasibility of using the augmented GPS-based system for aircraft navigation in Chilean airspace. Flight trials were conducted in December. Raytheon, prime for the U.S. WAAS system, in partnership with Chile's civil air navigation agency, installed the stations (see story on page 2).
Casio and IBM palmtop computers
scheduled for display at the Consumer Electronics Show in January in Las
Vegas will demonstrate the capability to store and display GPS-based road
maps of the entire United States.
Section News
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A collaborative international experiment to resolve some of the major problems stemming from lack of reliable information on GLONASS, and how to combine measurements of the Russian system with GPS, is underway this month.
The experiment, called IGEX-98, was a major point of discussion at the meeting, the third, of the ION GLONASS/GPS Interoperability Working Group (IWG) during the ION GPS-98 meeting in Nashville. Several Russian officials participated in the IWG meeting.
The experiment brings together the scientific, navigation and manufacturing communities in an international network of data-gathering facilities. Sites have been identified in more than 30 countries to comprise the first global network of stations tracking GLONASS. Participation is voluntary, and the data and products are in the public domain on the Internet. Those cooperating in IGEX-98 include the International GPS Service, the International Assn. of Geodesy, the International Earth Rotation Services, and the ION IWG.
Goals of Program
According to a briefing presented by James Slater to the IWG in Nashville, the goals of the global experiment are to:
Data from global sites is being gathered daily at two data centers - the Institut Geographique National in France, and NASA's Crustal Dynamics Data Information System at Goddard Space in Maryland. Information on the experiment and on products therefrom can be obtained from these websites: http://lareg.ensg.ign.fr/IGEX, and at http://www.ion.org/workgroup.html.
Russian Update
Dr. Pratap Misra, chair of the IWG, introduced two Russians at the meeting, Prof. Nikolai Ivanov of the Russian Institute of Space Device Engineering, and Vladimir Mitrikas, GEO-ZUP Co. Prof. Ivanov said the new GLONASS M spacecraft will have an expected design life of 7 years, compared with 3 years for current satellites. They will include a standard civilian signal broadcast on L2 and additions to the navigation message.
Mitrikas said the current tracking schedule used by the international SLR (Satellite Laser Ranging) community is inadequate to determine GLONASS orbits due to the lack of sufficient observations. Only three Russian stations, he said, are capable of tracking GLONASS.
ION Supplies Receivers
The ION Satellite Division, responding to urgent pleas for aid, quickly polled members of its Executive Committee in late November to win approval of $5,000 from the Division to assist the financially-strapped Russians to acquire receivers for participation in the IGEX-98 experiment. Dr. Misra, chair, and James A. Slater, co-chair of the IWG, urged the support; Ron Hatch, chair, Executive Committee, then in Japan on business, directed the polling via email of Committee members to gain the votes for approval for the late-hour financial aid.
The funds allowed the shipping and handling of three Javad
dual-frequency GPS/GLONASS receivers (on loan) to remote laboratory sites
in Russia. The equipment will enable the Central Research Institute for
Geodesy in Moscow to collect valuable data at the three sites, and make
a unique contribution benefiting the IGEX-98 international experiment.
Peter Daly of UK is Winner of 1998 Kepler
Award
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Prof. Peter Daly of the University of Leeds, United Kingdom, was lauded for his work on the signal structure and other facets of the Russian GLONASS system as the recipient this year of the coveted Johannes Kepler Award.
The award, given annually for sustained and significant contributions to satellite navigation, was presented at the ION GPS-98 conference held in Nashville, TN, Sept 15-18, by the chairman of the ION Satellite Division, Gaylord Green.
Daly joined the engineering faculty at Leeds in 1967. His group at Leeds built the first University-developed GPS receiver in 1985. In 1986, Daly received a best-paper award from the IEEE Plans conference for his presentation on deciphering the entire C/A code signal structure of the GLONASS system. Shortly thereafter, he also unraveled the code, modulation and complete data message of the GLONASS P-code signals. Also in 1986, Daly's group built the first combined GPS/GLONASS receiver capable of 3-D navigation.
Daly's research at Leeds led to a patent in GNSS receiver attitude determination, and a pending patent application for a new method of acquiring wideband transmissions for GPS satellites.
Long recognized for his participation as a lecturer and
panelist at numerous international meetings, Daly also is author or co-author
of more than 180 papers. He serves as a reviewer for a number of journals,
including ION's quarterly, NAVIGATION.
GPS Decision Pending at Top Echeleons
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The federal GPS Interagency Advisory Council (GIAC) has recommended that selective availability (SA) be turned off immediately and the last 12 Block IIR satellites, plus all of the upcoming Block IIF satellites, be modified to carry a second civil signal.
The vigorous GIAC stand formed a background to critical discussions concerning the modernization of GPS. Those discussions in the fall reached near the highest levels of government policy making, involving officials of the President's National Security Council (NSC) and his Office of Science and Technology Policy (OST), among others.
In its report, GIAC, representing non-transportation user agencies of GPS, also supported the FAA's need for a third aviation-protected GPS signal, provided the signal also supported requirements for centimeter-level land positioning. The recommendations were sent in a letter from GIAC's acting chair, Charles Challstrom of the National Geodetic Survey, to the co-chairs of the Interagency GPS Executive Board (IGEB). NSC and OST are part of the top policy-making IGEB, chaired by the Departments of Defense and Transportation, and including Commerce, State, Interior, Agriculture, Justice, NASA and the CIA. The IGEB must resolve the difficult issues of a 'modernized' GPS. The urgency to make those decisions may have slipped into next year due, in part, to the longer satellite lifetimes being experienced and the consequent possibility of sliding back spacecraft procurement contract dates.
The GIAC recommendations:
Need for Speed
While the GIAC letter did not mention the use of 'split spectrum' signals for civil use - one of the techniques known to be favored by the military - the letter did urge implementation of a second civil C/A code "at the earliest opportunity" to avoid problems expected during the solar maximum forecast for 2011-2012. A second signal would help correct for errors caused by solar storms in the ionosphere.
Concerning centimeter-level positioning, land users ideally prefer separations of about 100 MHz between signals. The most frequently mentioned spectrum for a proposed third civil frequency in the future with ARNS protection was 1181 MHz. That's only 46 MHz from the presently allocated L2, but marginally acceptable to land users if forced to compromise.
Share Signals
In an article prepared for GPS World magazine, Keith McDonald, former ION president, suggested that Europe, Japan and other countries be allowed to employ the same set of civil signals used by GPS on satellites they launch and control. "This internationally standardized signal arrangement," McDonald argued, "would serve worldwide emerging requirements, improve international compatibility, interoperability and availability."
"It would also allow the international community to more equitably share in the GPS industry's growth, and remove the threat of multiple standards and redundant equipage in international transportation."
Military's Choice
In a related development, a paper presented at the ION GPS-98 outlined a year-long analysis by the military of the best signal structure for the next 30 years to serve both military and civil users of GPS. The authors, Capt. David L. Lucia of the USAF Space Warfare Center and Capt. Jon Anderson of the USAF GPS Joint Program Office, said that a split spectrum military code with a centered civil C/A code, in both the L1 and L2 frequencies, offered the best solution.
"This enabled superior performance in anti-jam, achieved
superior backward compatibility with the existing signal structure, and
met all the performance needs of the civilian user community," the
authors found. "Based on the analysis, the GPS JPO has recommended
centered C/A and a 'split M-code' for implementation on both the L1 and
L2 frequencies." They noted that the GPS Independent Review Team (IRT)
and the Air Force Requirements Oversight Council have endorsed the JPO's
recommendation. A modulation scheme for a final M code is awaiting completion
of actual hardware tests.
Russians Seek European Support for GLONASS
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The European Community is evaluating a Russian offer to share control of Russia's Global Navigation Satellite System (GLONASS) in return for financial and technical support.
Anstoli Chilov, formerly with the defense ministry and now advisor to the Russian civil aviation authority, is quoted as telling European members of the GNSS 98 Symposium held in France Oct. 20 that the Russian military must preserve an essential role in GLONASS, but that, "We have agreed on the principle of shared control. We must now define, line by line, how our mutual requirements can be met."
Neil Kinnock of the European Commission on Transport welcomed the offer, but cautioned that the EC "must take into account the economic and political situation in Russia." With U.S. policy ruling out any shared control of GPS, Kinnock said nevertheless there must be continued cooperation with U.S. operators, which is to the interest of both parties. "The basic technical question," Kinnock said, "is whether, taking GLONASS as a starting point, we can develop a system (GNSS 2) that is interoperable with GPS in a cost effective way."
Spare-a-Dime Policy
Chilov disclosed that the GLONASS system was down to 12 operational satellites, but that three replacement satellites were ready for launch on a Proton vehicle. He proposed a program in which Europe would supply financial and technical support for the present system, and cooperate on development of the advanced M2 satellites to enter service in 2001 or later.
Doubts Expressed
Earlier, in a paper at the ION GPS-98 conference by Signal Computing Ltd., U.K., the authors found that GLONASS is likely to deteriorate further in the coming year as more satellites near end of lifetimes. "Despite many promises of launches by the Russians over the past two years, none have happened," the paper said.
The authors of the paper, David Holmes, Andrew Last and
Dr. Sally Basker, noted that a reduced GLONASS still provides 60 percent
coverage worldwide, and even greater, 80 percent, over Russia. The latter
figure, they said, may explain the Russians lack of urgency to rejuvenate
the system. (See related article on ION's GLONASS/GPS Interoperability Working
Group).
ION GPS-98 Draws Big; Papers Top Quality
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The ION GPS-98 meeting in Nashville, the self-styled foot-stomping country music capital of the world, drew slightly more than 2000 persons, up about 6 percent over the previous year's attendance in Kansas City, MO. During the four-day meeting in the Nashville Convention Center, 240 papers were presented; attendees rated the papers overall as of consistently high quality.
Crowds swarmed the exhibit hall where the latest technologies and products were professionally displayed. Dava Sobel, author of the best-selling book, LONGITUDE, provided a witty and entertaining presentation as guest luncheon speaker. As customary, the government-industry Civil GPS Service Interface Committee (CGSIC) held its meeting in the adjacent Renaissance Hotel prior to the full opening of ION GPS-98.
For your advanced planning, the meeting returns to Tennessee's capital city, Nashville, next year for ION GPS-99, Sept. 14-17.
Best Paper Awards for ION GPS-98
A1Results of Absolute Field Calibration of GPS Antenna PCV F. Menge, G. Seeber, C. Volksen, Insitut fur Erdmessung; G. Wubbena, M. Schmitz, Geo++, Gesellschaft fur satellitengestutzte geodatische und navigatorische Technologien mbH
B1Interoperation and Integration of Satellite Based Augmentation Systems, R. Fuller, D. Dai, T. Walter, C. Comp, P. Enge, D. Powell, Stanford University
C1Code Multiplexing Via Majority Logic For GPS Modernization, J. Spilker, R. Orr, Stanford Telecom; J. Anderson, GPS Joint Program Office
D1An Introduction to SnapTrack GPS Technology, N. Krasner, M. Moeglein, B. Wilson, SnapTrack Inc.
A2Analysis of the Three-Carrier Ambiguity Resolution (TCAR) Technique for Precise Relative Positioning in GNSS-2, U. Vollath, S. Birnbach, H. Landau, Spectra Precision terraSat GmbH; J.M. Farile-Ordonez, M. Martin-Neira
B2Verification of the LAAS Signal-In-Space Integrity Monitoring Algorithm, F. Liu, Ohio University
C2UK Development of a High Integrity GPS Guidance Enhanced Receiver, A. Maloney, B. Lumsden, Defence Evaluation and Research Agency; P. Mcllroy, Raytheon Systems Ltd.
D2 Co-Op Tracking For Carrier Phase, M. Zhodzishsky, S. Udanov, V. Veitcel, J. Ashjaee, Javad Positioning Systems
A3The Residual Tropospheric Propogation Delay: How Bad Can It Get?, J.P. Collins, R. Langley, University of New Brunswick
B3Measurement Error and Protection Envelopes in the Presence of Interference for GNSS Receivers, J.-M. Lopez-Almansa, P. Pablos, TTC & RF Navigation Section
C3Direct Platform Orientation and Georeferenced Data Collection with Tightly Integrated GPS/INS In Airborne Applications, D. Grejner-Brzezinsk, The Ohio State University Center for Mapping
D3An Operational Airborne Lidar Survey System Using Kinematic DGPS, M. Reed, John E. Chance & Associates, Inc.
A4The Mitigation of Static Carrier Phase Multipath Effects Using Multiple Closely-Spaced Antennas, J.K. Ray, M.E. Cannon, The University of Calgary; P. Fenton, NovAtel Inc.
B4Design of High Performances and Cost Efficient Constellation for a Future Global Navigation Satellite System, M. Roomy, Merino; J.A.P. Cobo, GMV
C4Inflight Demonstration of a GPS-Based Pathway-In the Sky Flight Display For Curved Approaches and Missed Approaches in Mountainous Regions, K. Alter, A. Barrows, B. Parkinson, J.D. Powell, Stanford University
D4DGNSS Radiobeacons-The European Frequency Problem, D. Last, B.E. Turhan, University of Wales
A5Use of Covariance Analysis Technique for Predicting Performance of Regional Area Differential Code and Carrier-Phase Networks, J. Raquet, The University of Calgary
B5Stewardship - Growing Need to Manage a National Asset, D. Latterman, D. Martens, Science Applications International Corporation
C5MicroGPS: On-Orbit Demonstration of a New Approach to GPS for Space Applications, J. Srinivasan, Y. Bar-Sever, W. Bertiger, S. Lichten, R. Muellerschoen, T. Munson, D. Spitzmesser, J. Tien, S.-C. Wu, Jet Propulsion Lab
D5GPS Satellite Clock Event On SV 27 And Its Impact On Augmented Navigation Systems, A. Hansen, T. Walter, D. Lawrence, P. Enge, Stanford University
E5The Impact of Operating GPS With More Rubidium Frequency Standards, H. Mobbs, D. Crater, U.S. Air Force
A6Experiments in GPS Attitude Determination for Spinning Spacecraft With Nonaligned Antenna Arrays, J. Adams, E. Olsen, J. How, Stanford University
B6A New Civil Split Spectrum C/A Signal for the L2 Channel, J. Spilker, Stanford Telecom; B. Parkinson, Stanford University; J. Andreson, GPS Joint Program Office; J. Betz, The MITRE Corp.
C63D Formation Flight using Differential Carrier-Phase GPS Sensors, E. Olsen, C-W. Park, J. How, Stanford University
D6Reducing the GPS Ambiguity Search Space by Including
Inertial Data, J. Skaloud, University of Calgary
Congress Funds WAAS, LAAS, and LORAN
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Congress Funds WAAS, LAAS, And LORAN
In one of the final acts of the 105th Congress, lawmakers approved a compromise transportation appropriations measure that provided funding for FAA's embattled Wide Area Augmentation System (WAAS), and well as for the Local Area (LAAS) system and improvements in Loran-C for the fiscal year 1999 (FY99) that began last October 1.
The WAAS program received $85 million, about 18 percent less than originally sought by the Administration. The FAA's other satellite-based system of the future, LAAS, received $34.175 million for FY99. Lawmakers allocated $7 million to Loran-C for upgrades to that established ground-based radionavigation system.
Restrictions
The funds were part of a massive omnibus appropriations bill carrying monies to run the Department of Transportation and seven other major departments for the current fiscal year. President Clinton signed it into law, as Public Law 105-277.
The Senate withdrew tough language prohibiting the FAA from spending WAAS funds until it proved the system could serve as a sole means of navigation; opponents said that provision would have delayed, perhaps killed the program. But the final Senate-House compromise retained critical language in its report, restricting WAAS activities to phase one of the program. "The conferees intend for FAA to take a 'time out' at this point," the report said, "to reassess the justification for the program beyond phase one."
In addition to a slow-down forced by a skeptical Congress, which made the huge cut in the WAAS FY99 budget (from $127 million to $85 million) and restricted progress to phase one, the program is haunted by the uncertainty of a critical risk assessment study being conducted under contract by Johns Hopkins Applied Physics Labs. The results of that study to determine, in part, the capability of WAAS to serve as a sole means of aviation navigation, is not due until January.
Critiques
In other developments, DoT Inspector General Kenneth Mead said in a critical review in October that "the FAA should formally acknowledge that its current schedule for the operation of the final phase of WAAS, December 2001, will not be met." Meanwhile, with the WAAS program also in trouble in Congress, the FAA was said by Aviation Week magazine to be considering slipping the initial and full operational dates some months, adding 25 more ground reference stations and using capacity on only two Inmarsat satellites initially.
Congress: 'Enhanced' GPS
In a separate authorization bill, Congress passed strong language declaring that "an enhanced Global Positioning System program" is a matter of urgent national security priority. The bill, which came out of the House National Security and Senate Armed Services Committees, defined an "enhanced GPS" as including the following elements:
The bill, signed into law by President Clinton, authorized
up to $44 million in FY99 to finance the Pentagon portion of the "enhanced"
system. At the same time, a restriction was lifted on the use of funds for
ships, planes and tanks not equipped with GPS by 2000. It extended that
deadline to 2005.
From The Editor
Hale Montgomery
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A two-page joint U.S.-Japan statement released by the White House on cooperative use of GPS is a model of international comity.
A harmonious spirit prevails, reflecting perhaps the Japanese culture of cooperation where mutual benefits may exist. Japan's current widespread use of GPS in vehicle navigation systems - about 400,000 cars - far exceeds the U.S. market in this consumer application. The statement notes that both countries operate maritime differential GPS systems, and are developing GPS-based air navigation systems: the U.S. Wide Area Augmentation System (WAAS) and the Japanese look-alike service that will fly on their Multi-functional Transport Satellite (MTSAT) system.
Japan made a firm commitment almost two years ago to support space-based aviation navigation by acquiring WAAS software as part of competitive bidding on the MTSAT system. Raytheon Systems, prime contractor to the FAA for WAAS, is now also contractor for phase one WAAS software for Japan. Airlines may some day enjoy seamless WAAS-compatible navigation support in the Asian third of the world when the Japanese system becomes operational.
Returning to the statement, both governments in a broad sense avow a common interest in enhancing the civil utility of GPS, expressing their intent "to cooperate to promote and facilitate civilian use of GPS." The United States promises to provide the GPS standard positioning service (SPS) on a "continuous, worldwide basis, free of direct user fees;" Japan says in turn it plans to work closely with U.S. officials to establish the GPS SPS "as a worldwide positioning, navigation and timing standard."
In a more narrow sense, the carefully parsed, tightly wound words of the statement discuss a cooperative mechanism for future bilateral cooperation on use of GPS. A plenary meeting will be held yearly "to review and discuss matters of importance regarding the use of the GPS SPS." Future discussions will focus on "measures to identify and report intentional and unintentional interference, the use of the GPS SPS in emergency situations, and an emergency notification system."
In a diplomatic manner, that language refers to Japanese concerns about improved notice of interference problems, and advance warning in "emergency situations," meaning security measures that may be necessary for U.S. military purposes. In interference matters, there already is talk that the USAF is considering a 800-like GPS telephone line for expedited, direct reporting of incidents, in addition to the reporting mechanism now in place and working through the Coast Guard bulletin board. Concerning military security measures, the Pentagon's navwar program is aimed at resolving the problem of protecting GPS military signals in times of combat while maintaining civil signal integrity.
In Europe, where a more competitive culture exists, small
progress has been made on a similar cooperative agreement. Europeans have
built their own WAAS-like testbed. U.S.-developed and financed standards
for the signal in space and for avionics are "open literature,"
available through the International Civil Aviation Organization (ICAO) in
Montreal. The Satellite-based Augmentation System Technical Interoperability
Working Group acts as a forum for all providers - U.S., Canadian, Japanese
and European - to exchange technical information on WAAS-like efforts. Thus,
the European early bird version, called EGNOS, will be compatible with the
U.S. WAAS, but 'built here' as in Europe, not 'over there' in the States.
Aviator/Author Polhemus Dies at Age 74
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Major William L. Polhemus (USAF ret.), award-winning air navigator, engineer, author and former president of ION (1969-70), passed away on September 15, 1998. His fascinating article about the mysterious disappearance in the South Pacific of Amelia Earhart and Fred Noonan in 1937 appeared in the last issue, Summer 1998 edition, of this newsletter.
Polhemus was a winner of ION's Weems, Superior Achievement and Burka Awards, and a Fellow of the Royal Institute of Navigation.
He served 22 years on active duty in the military, flying as a Navy aircrewman on Curtis Helldivers and Grumman Avenger torpedo-bombers in WW II. While with the USAF, he served on B-26s as a navigator-bombardier in the Korean War, with the Military Air Transport Service over the North Atlantic, and with SAC as navigator-bombardier on B-47s and the mach 2
B-58 Hustler. He and his crew received the Earnest Harmon Trophy from President Kennedy for completion of the first supersonic crossing of the Atlantic and establishment of a world speed record of 3'19'' between New York and Paris.
Polhemus and his crew were awarded the Mckay Trophy in 1961 for establishing three world records over a 2000-kilometer closed course originating at Edwards AFB, California. After his military career in the mid-1960s, he flew with AirCanada on DC-8s, and in 1967 he navigated a commemorative flight on a restored Lockheed L-10 over New Guinea, marking the 30th anniversary of the ill-fated Earhart-Noonan flight.
From The ION Historian
Marvin May
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The Mariners' Museum in Newport News,Virginia, is considered to be America's premier maritime museum. Each of its 13 spacious galleries has a story of its own, from a treasure chest of figureheads, ship models, and navigational instruments to the world-renowned August Crabtree Collection of Miniature Ships afloat on waves of silence. During a recent visit there in mid-August, we found the museum featuring two popular special exhibits: "Titanic: Life and Times" and "Admiral Nelson: A Time for Heroes".
Arthur Milton Huntington (1870-1955), recognizing the ocean's pervasive influence on man throughout history, dedicated the Mariner's Museum to preserving "the culture of the sea." Later, the son of Collis P. Huntington, railroad magnate and founder of Newport News Shipbuilding and Dry Dock Co., Archer Huntington and his wife, the noted sculptor, Anna Vaughan Hyatt, established this museum and others which now stand as a testament to their efforts.
An interesting collection of navigation instruments is on display, particularly those in the Chesapeake Bay and Age of Exploration galleries. Included are a variety of 17th century backstaffs, astrolabes, quadrants and compasses. Artifacts displayed from the 18th century include early marine chronometers, double frame quintants, and numerous magnetic compasses.
In addition to the displays open to the public, the museum owns a wide collection of navigation-related instruments and research archives. Ms. Jeanne Willoz-Egnor, the museum's knowledgeable Collection's Manager, indicates that there are over 400 navigation related instruments in their collection, including alidades, over 90 compasses, 35 chronometers, artificial horizons, depth gauges, depth sounders, patent logs, electric logs, peloruses, radio direction finders, reflecting circles, over 18 sextants, stadimeters, transits, and orreries.
The Mariner's Museum is planning an ambitious exhibit beginning in September 1999 that will feature the history, present and future, of navigation. In coordination with Willem F.J. Morzer Bruyns, Senior Curator (Navigation) of the Nederlands Scheepvaartmuseum in Amsterdam, the exhibit will highlight the incredible differences in navigation instrumentation over the period from 1774 to 2000. The exhibit will consist of four elements based on the chronological periods from 1) 1774-1800, 2) 1800-1970, 3)1970-1999, and 4) future navigation (21st century). Each of the four elements will contain recreated displays of equipment as they were installed aboard vessels, or sketches of potential applications.
Ms. Willoz-Egnor expressed a desire for assistance with research in the areas of modern and future navigation. In addition, organizations or individuals who have access to modern navigation instruments which could be added to this exhibit are also being solicited. The specific devices presently identified include: Thompsons sounding machine, electronic sounding machine, radio direction finder, Omega, Decca, Loran, radar, and GPS receivers. I volunteered to coordinate assistance through the ION. I strongly recommend a visit to the Mariners' Museum. Further information may be found at their excellent website, www.mariner.org.
Mobile COM Users Continue Challenge to GPS Spectrum
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Although Inmarsat has withdrawn its advocacy for sharing the lower portion of the GPS band with mobile satellite communications users, other mobile-com vendors this year had not as yet given up their quest to share part of the GPS band now used for L1 civil signals. The United Kingdom and other mobile satellite vendors can press ahead with the challenge outside of Inmarsat, officials cautioned.
Several papers presented at the ION GPS-98 meeting in Nashville in September sent the message that GPS users must remain en garde against mobile satellite services (MSS) vendors.
Rudolph Kalafus, Trimble Navigation, said in a paper that efforts by MSS operators to "share" the lower part of the GPS band, at 1559-1610 MHz, for mobile communications services at the World Radio Conference (WRC) in Geneva last year "nearly succeeded, and would have if not for a last-ditch effort by GPS aviation and commercial interests." MSS proponents will be back to try again at WRC 2000. GPS supporters contend MSS signals will cause fatal interference to navigation safety-of-life services.
Ironically, the consequences of the MSS industry's undying pursuit of a shared com/nav signal might actually hurt their communications users. Kalafus pointed out that "satellite cell phones could jam GPS receivers in the same vehicle or in nearby vehicles on the road." Likewise, passengers with handheld phones on cruise ships or airliners could inadvertently jam GPS receivers on their own transport.
And there are many examples of interdependence. For example, the telecommunications industry relies on GPS timing to control its networks, while the navigation industry depends on communications links to relay differential corrections. The communications and navigation markets overlap, "a large segment of the users of each are the same people," he declared.
As a result, Kalafus expressed optimism that "the mutual interests of bothwill result in solutions being found to enhance both services."
In another paper, an analysis of MSS interference to GPS/WAAS conducted by Rockwell Collins concluded that the data "demonstrate the possibility of significant degradation to GPS/WAAS performance for aviation users." The paper, by Gary McGraw and Robert Erlandson, said even in the most optimistic case of negligible intermodulation spillover in the MSS space-to-ground signal, there would be some degradation of the WAAS signal which could affect "WAAS precision approach availability." Beyond that, the authors found that proposed MSS band sharing at lower (1559-1610 MHz) portion of GPS spectrum "would preclude future GNSS services located in the lower part of the RNSS/ARNS band."
NGS Selects Chief Geodesist Dr. Dennis G. Milbert has been selected as chief geodesist at NOAA's National Geodetic Survey (NGS), replacing William E. Strange who retired earlier this year. Dr. Milbert has worked at NGS since 1947 on projects covering control networks, least squares adjustments, satellite altimetry, GPS and physical geodesy. Examples of his recent work include GEOID90, GEOID93 AND GEOID96 geoid height models. He received his MS and PhD degrees from Ohio State University. Dr. Milbert is on the editorial board of the Journal of Geodesy, co-secreary of the International Geoid Commission, and is a recipient of the Heiskanen senior aware and the NOAA Administrator's Award. |
Corporate Profile 746th Test Squadron U.S. Air Force The 746th Test Squadron, also known as the Central Inertial Guidance Test Facility (CIGTF), has been active in testing and evaluating inertial components, aircraft navigation systems, and missile guidance systems since its birth in 1957. The facilities at the CIGTF allow tests to be tailored to specific objectives. Through an integrated approach to test programs, developing agencies obtain an independent assessment of system performance and test results. The CIGTF is the Responsible Test Organization for tests involving the Global Positioning System (GPS). It is responsible for the test, evaluation, and verification of GPS user equipment and GPS integrated navigation systems. New reference systems with submeter accuracies are available to the testing community, which provide a highly accurate airborne position, velocity, and attitude reference. The inertial laboratory has the capability to conduct both static and dynamic tests. These capabilities include gyro and accelerometer test tables, centrifuges, seismically stable platforms, linear vibrators, and GPS performance and jamming simulation test facilities. Both sled and flight tests are conducted to evaluate navigation and guidance systems. All test data can be analyzed by CIGTF analyst experts. The 746th Test Squadron is the DoD's center of excellence for test and evaluation of inertial and inertial aided navigation and guidance systems for aircraft, missiles, and spacecraft. Aircraft available for flight testing are the C-12, F-15, F-16, and UH-1H. The 746th Test Squadron is also the Responsible Test Organization for GPS-aided inertial navigation systems. |
New Corporate Members The ION extends a warm welcome to the following new Corporate Members:
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Calendar January 1999 25-27: ION National Technical Meeting, ION CIGTF; Catamaran Hotel, San Diego, CA; Contact: ION, Tel: 703-683-7101, Fax: 703-683-7105, Web Site: http://www.ion.org 28-29: RTCM Special Committee 104 on Differential GNSS (Global Navigation Satellite Systems) Service; San Diego, CA; Contact: R.M. Kalafus, Tel: 408-481-2087 May 1999 9-14: 1999 Annual Assembly Meeting of the Radio Technical Commission for Maritime Services (RTCM); Wyndham Palace Hotel, Orlando, FL; Contact: W.T. Adams, Tel: 703-684-4481, Fax: 703-836-4229 24-26: Sixth St. Petersburg International Conference on Integrated Navigation Systems; St. Petersburg, Russia; Contact: Dr. George Schmidt, Draper Laboratory, Tel: 617-258-3841, Fax: 617-258-3355, Web Site: http://www.draper.com June 1999 28-30: ION 55th Annual Meeting; Royal Sonesta Hotel, Cambridge, MA; Contact: ION, Tel: 703-683-7101, Fax: 703-683-7105, Web Site: http://www.ion.org September 1999 14-17: ION GPS 99, The Satellite Division of the Institute of Navigation 12th International Technical Meeting, Nashville, TN;Contact: ION, Tel: 703-683-7101, Fax: 703-683-7105, Web Site: http://www.ion.org |
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