Ambassador Schoettler at ION GPS Plenary

EC Issues Galileo Report
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On Nov. 22, the European Commission issued a report that marks the end of the definition phase of Galileo, the European satellite navigation project for civil uses.

“Galileo will provide Europe with a safe and powerful tool for developing new services: positioning in transport, telemedicine, tagging of prisoners in law enforcement, or application of fertilizer in farming. The policy decisions to be taken by the Transport Council on Dec. 20 are vital if these prospects are to become reality,” Mrs. Loyola de Palacio, vice president of the commission responsible for energy and transport, said.

The Galileo program, as presented by the Commission and supported by the European Council and the European Parliament, will be operated and controlled by civilians. Development is proposed in four phases: definition in 2000, development and validation by 2005, deployment by 2007, and operation and use thereafter.

The report the Commission adopted presents the results of the definition phase of Galileo that it has undertaken together with the European Space Agency. It confirms the strategic and economic interest of the program and proposes to the Transport Council on Dec. 20, that it be continued in 2001, although accompanied by a number of conditions that are indispensable to the success of Galileo:

Deployment of the European Union’s own satellite constellation. This is a prerequisite for the EU’s independence in the field of satellite navigation. It would be made up of 30 satellites in orbit around the Earth at an altitude of some 23,000 kilometers.

Guarantee of sufficient financing by 2007. Cost-benefit studies show Galileo to be profitable and sufficiently attractive for public financing in the form of subsidies not to be needed after 2007.

• However, financing based on public subsidies (X1.1 billion) will be indispensable for the development and validation phase (2001-2005). This has already been scheduled, with 50% each from the budgets of the Community and the European Space Agency. There will be no need to seek additional public funding.
• Investment from the private sector to the tune of X1.5 billion will be needed for the deployment phase (2006-2007) (X2.1 billion), which will consist of constructing and launching the satellites as well as establishing the terrestrial infrastructure network. A public-private partnership will need to be set up for this purpose on completion of the development and validation phase.

Provision of an adequate legal and financial framework. This has to be established as soon as possible in order to attract the private financing needed to operate Galileo:

• Creation as from 2001 of a provisional, coordinated management structure for the Galileo project involving the Commission and the European Space Agency.
• Creation at the earliest of a single, definitive management structure with an investment budget combining all the funds earmarked for the project.
• Provision of this structure with supervision over EGNOS, the precursor of Galileo.

The European Commission’s report and the commission’s staff working paper on the Cost Benefit Analysis Results for Galileo can be downloaded at the Galileo Web site at www.galileo-pgm.org.

FROM THE ION PRESIDENT: ___________________ ION GPS Conference Continues to be a Hit The ION GPS Conference continues to outdo itself, and this year was no exception. We had over 2100 attendees representing 40 countries and there were 340 papers presented in six parallel tracks of sessions. More than 100 companies displayed their products in the exhibit hall. The plenary keynote speech was given by Ambassador Gail Schoettler who served as the U.S. Ambassador to the World Radio-communication Conference held in Istanbul last May. Ambassador Schoettler provided a recap of the events that led up to and took place during WRC 2000. Although WRC 2000 was a great success for the United States, she encouraged stakeholders to start early in preparing for WRC 2003 and for the ION to play a key role in educating policy makers about the issues. This talk set the stage for many of the papers presented in the following days of the conference on spectrum coordination, as well as interference testing and mitigation. We also had our youngest presenter at an ION Conference, 16 year-old Casey Miller from Beavercreek, Ohio, who gave an excellent paper on “A Novel GPS-Based Training Device to Improve Track and Cross-Country Training Effectiveness.” This paper won the best presentation award in the session. He also will be giving this presentation at an upcoming Dayton section meeting. In addition, seventeen students were awarded travel grants from the ION to present papers at the conference. They were provided with a full complimentary conference registration, airfare, hotel accommodations, and a stipend to cover miscellaneous expenses. It should be noted that only one of the students was from the U.S. Dr. Per Enge, immediate past president of the ION, was the recipient of this year’s Kepler Award. Further information on this award, as well as the Best Presentation Awards, are provided in the newsletter. Congratulations to all! I would like to thank the ION GPS 2000 program chairs Larry Hothem, General Chair, and Sally Frodge, Technical Chair, and the Track Chairs for all of their hard work in making this year’s meeting such a success. In addition, I would like to acknowledge the outgoing Satellite Division officers: Ron Hatch, Steve Malys, Richard Barker, Gaylord Green, Changdon Kee, and Guenter Hein. The incoming Satellite Division Officers are as follow: Penny Axelrad, Chair John Lavrakas, Vice Chair Boris Pervan, Secretary John Clark, Treasurer Lyn Dutton, European Rep Bill Bunton, Asian Rep In association with the American Association for the Advancement of Science (AAAS), the ION has appointed Phil Ward as its first ION Congressional Fellow. Phil recently attended the AAAS Fellow orientation program in Washington, DC and has written an article about the process which appears in this newsletter. We look forward to hearing more from him as his Fellowship progresses. I would like to encourage the membership to submit nominations by Dec. 15 for 2001 ION Fellows and nominations for Annual Awards by Feb. 21, 2001. Nominations are to be submitted to the ION National Office. Finally, the ION National Technical Meeting will be held in Long Beach, Calif., Jan. 22-24, 2001, and will include a classified session to be held at The Aerospace Corp.

The Purpose of The ION The Institute of Navigation, founded in 1945, is a non-profit professional society dedicated to the advancement of the art and science of navigation. It serves a diverse community including those interested in air, space, marine, land navigation and position determination. Although basically a national organization, its membership is worldwide, and it is affiliated with the International Association of the Institutes of Navigation. 2000-01 National Executive Committee President: Karen Van Dyke Executive Vice President: Ron Hatch Treasurer: Larry Hothem Eastern Region Vice President: Sally Frodge Central Region Vice President: Maj. John Raquet Western Region Vice President: Dr. A.J. Van Dierendonck Immediate Past President: Dr. Per Enge How to Reach The ION Telephone: 703-683-7101 Facsimile: 703-683-7105 Web site: http://www.ion.org E-Mail: membership@ion.org ION National Office Staff Director of Operations: Lisa Beaty Technical Director: Carl Andren Office Manager: Jennifer Murphy-Smith Assistant to the Technical Director: Miriam Lewis Meeting Services/Author Liaison: Connie Mayes Publication Department: Wendy Hickman Graphic Design & Layout: Paula Danko CORRECTION In the Summer 2000 issue of the ION Newsletter, we failed to report the names of some of the ION 2000–2001 officers. The officers who were inadvertently omitted are as follows: Air Representative, Mr. Tim Murphy, The Boeing Company; Land Representative, Mr. Robert French, R&D French Associates; Marine Representative, Capt. Richard Hartnett, U.S. Coast Guard Academy; Space Representative, Dr. Larry Young, Jet Propulsion Laboratory Our sincere apologies for the oversight.

From the ION Congressional Fellow: Freshman Orientation
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Under the sponsorship of The Institute of Navigation, I attended the American Association for the Advancement of Science (AAAS) 2000-2001 Fellow Orientation Program in Washington, D.C. from Wednesday, Sept. 6 to Wednesday, Sept. 20, 2000. I stayed an extra day to distribute my curriculum vitae to 20 senators and 16 representatives for a total of 17 days. My own district representative (TX, 5th), Rep. Pete Sessions, happens to also be a personal friend. Pete had already asked me to be on his staff, so I had a “bird in the hand” before my orientation and now I have “36 birds in the bush.” I took my wife, Nancy, to search out the local housing situation and to prioritize locations most suitable for our expected situation. Nancy is such a great networker that she was also of great benefit to me in establishing good relations with the other fellows who attended this orientation (more than a 5-to-1 ratio of women to men).

There were 99 fellows participating in this orientation program. Of these, there were a total of 39 congressional fellows, of which 12 are January 2001 starts. Most (60) of the fellows (executive fellows, diplomacy fellows, etc.) were already placed as a result of their selection process because their stipends are paid by their designated government organization. The normal outcome of the AAAS orientation program for congressional fellows is to begin soliciting for interviews for a legislative staff position the day following orientation.

Don’t Jump the Gun
The AAAS encourages the congressional fellows not to “jump the gun” on distributing their CV to members of the House and Senate because they believe that the orientation process could provide new insights into the legislative process that could change their policy interests. In the end, we were encouraged to seek out legislative members with committee affiliations most suited to our science and technology background, but to expect to work on a diversity of tasks, including answering the mail for the member. A congressional fellow may also work on a standing committee (either in the House or Senate) or in the Congressional Research Service (CRS) that is part of the Library of Congress. The CRS is available only to members of the House or Senate and receives over 2000 research requests per day.

We were advised to seek an assignment with a legislative member and staff whose politics are largely compatible with our own, even though we are performing a non-partisan party service as science and technology “experts” on their staff. This is because there will be legislation going on that does not involve science and technology, but we will be exposed to the staff opinions, discussions and atmosphere on a daily basis in a very “tight knit,” high pressure environment, and we will be expected to support the member in every aspect of his legislative activity and public opinions. Others shared that they found a satisfactory working relationship with moderate members of the opposite party and they recommended that we seriously consider aligning with the “majority party,” especially in the House of Representatives. Some past congressional fellows who came on in an election year as September starts, found a wonderful assignment with a member in the House of Representatives, only to find a new job because either the member was not re-elected or the member’s party became the “minority party” and their staff size was cut.

I plan to wait until after the November elections to begin serious efforts at interviewing. Even if invited to interview early, I will not make any decision until the outcome of the election because it is important to me to work with the majority party.

A Lot of Information
The AAAS orientation covered every aspect of the political environment in the legislative branch as well as the executive branch, state department, and numerous federal agencies. I was impressed with the senior level and high caliber of the speakers they invited to participate in the various sessions. It was also beneficial to visit many official buildings (Dirkson Senate office building, Rayburn House office building, Capitol Building, Library of Congress, Eisenhower, White House building, etc.) for many of the sessions. There were a lot of handout materials, too much to carry, so I shipped a large box of books and other papers.

I look forward to my year in Washington, D.C. and am excited about the prospects for participation in the science and technology aspects of the legislative process as well as the full exposure to the political atmosphere.

The Removal of Selective Availability: The Impact on the Geodetic Community
Terry Moore and Chris Hill
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On May 1 this year, millions of users of GPS around the world were given a free upgrade to their receivers. The artificial degradation known as Selective Availability (SA) was removed from the GPS signals, and horizontal navigation accuracies jumped from a specified 100m to around 15m overnight. This followed a promise from the US President in 1996 that SA would be removed by 2006, and the need for its continued use would be reviewed every year from 2000. Fortunately, at the first review, the decision was made to remove it. SA was applied by ‘dithering’ the clocks on board the GPS satellites, so that the accuracy of any range measurement was no better than about 30 m. The effect was to cause the position indicated by a stand-alone receiver to wander about in an unpredictable manner, at speeds of up to 5km per hour. Figure 1 shows a typical plot of horizontal accuracy, from two hours of tracking with a static receiver. To anyone who was first exposed to GPS after SA was applied, in 1991, the accuracy now achievable with a stand-alone receiver is quite remarkable. Even to those working with GPS before SA, the various improvements to receiver technology and the system itself have had a surprisingly beneficial effect. There is now an over-specification constellation (28 satellites at the time of writing), with broadcast orbits that are more accurate than ever. Even the cheapest receiver has enough receiving channels to track all the satellites above the horizon, and the measurements made by the best receivers are more precise than the system designers ever expected. Typical Accuracy The following plots show what could be achieved under SA conditions, and what can now be achieved, with a cheap hand-held receiver. Measurements taken every 30 seconds over a 24 hour period lead to 2880 separate position solutions. Horizontally, 95 percent of these solutions are within 8m of the mean. To achieve this sort of accuracy, users previously had to invest in separate equipment to allow the stand-alone measurements to be differentially corrected against a reference station - a technique known as Differential GPS (DGPS). The advantages of DGPS in this post-SA world are now less clear-cut. Figure 3 shows the effect of differentially correcting the results in Figure 2. There is an improvement, but DGPS no longer has the dramatic benefit that it used to. 95 percent of the horizontal DGPS positions are now within 5.7m of the mean. Of course, these two figures only show the spread of results around the mean. The question that most surveyors would ask is how close is the mean to the truth in each case. In the DGPS case, the horizontal mean is only 10cm from the truth. The surprising result is that the mean of the stand-alone horizontal positions is no more than 40cm from the truth, after only 24 hours.

Many users may decide that this sort of stand-alone performance is quite adequate for their purposes. However, other users may appreciate the extra assurance that DGPS gives, that the solution is correct. They may also require the extra accuracy that DGPS gives.

Height Problems As we’ve seen above, the improvement in horizontal accuracy is not great, but the effect on height is more important. In the above example, 95 percent of the DGPS height solutions are within 11m of the truth, whereas the figure for the stand-alone solutions is 26m. In fact, the stand-alone heights are significantly biased, with the mean being over 13m from the truth, whereas the mean DGPS height is within 70cm of the truth. The cause of the poorer height performance in the stand-alone case is the atmosphere, which slows the satellite signals, leading to errors in the range measurements. If a receiver can see satellites in all directions, giving a good distribution in azimuth, then the effects of atmospheric errors can average out to virtually nothing in a horizontal position solution. Clearly though, it is impossible to have the equivalent distribution in elevation, since the receiver will never see satellites below the horizon. Atmospheric errors will therefore always affect height more than they do horizontal position. The above results have all been produced with single-frequency (L1 only) data, so the effects of both the troposphere and the ionosphere are present. Dual-frequency receivers are able to eliminate most of the ionospheric effect because it is frequency-dependent. However, the tropospheric effect is the same for both GPS frequencies, and cannot be eliminated this way. It therefore remains as one of the dominant errors in GPS, now that SA has gone.

Differential GPS improves the accuracy because the atmospheric errors (as well as most of the other error sources) are almost the same at two nearby locations. A reference receiver at a known location will be affected by almost the same atmosphere as a user’s receiver, at a distance of up to several hundred kilometres. Only when the distance between the reference and the user is such that the two experience significantly different atmospheric effects, does the technique cease to be of use.

DGPS Corrections
DGPS is a technique that really came into its own when SA was introduced. Since the clock dither is a one-dimensional error (i.e., all users will experience the same effect, regardless of how far apart they are), DGPS was able to counter SA even at very long ranges. However, to do this effectively, the DGPS corrections had to come at a rate that could keep up with the rapid changes in the SA clock dither. Typically, the DGPS corrections were considered too old if it took more than about 10 seconds from the moment they were computed to the moment they were applied by the user. This placed a considerable strain on DGPS systems, particularly in the communication channel used to broadcast the corrections to the users. Now that SA has gone, the situation is quite different. The remaining errors, mostly atmosphere and satellite orbits, change much more slowly, so that a DGPS correction will not age for possibly several minutes. This will relieve the strain on the communication channel and could even lead to innovative communications options that would previously have been considered too slow.

Impact of the Removal of SA
A further impact of the removal of SA will be seen in the apparent performance of different receivers. SA was something of a leveller, and most receivers, operating in a stand-alone mode, had a similar performance. With SA off, the quality of the receiver hardware, and the models within its firmware, will be far more evident. As a result, the good receivers will provide a more significant improvement in accuracy than others that are perhaps not so well designed or manufactured.

High precision surveying with GPS has always been accomplished with carrier phase systems. Carrier phase observations from two receivers lead to very accurate measurements, at the centimetre level, of the vector between the receivers. To achieve this accuracy, carrier phase observations are normally processed as ‘double differences’ (two receivers, two satellites). This approach has the advantage that any error sources common to pairs of differenced observations are eliminated. As we saw above, SA’s clock dither is common to any measurements made to a particular satellite, provided they are all made at exactly the same time (or within a few milliseconds of each other). As a result, the traditional double difference technique was virtually immune to the effects of SA, a fact which has allowed carrier phase surveying to continue and develop over the last decade in spite of SA.

In fact, carrier phase surveying has developed to such a level that most GPS manufacturers now offer systems that will allow carrier phase surveying with a mobile receiver—a technique known as real-time kinematic (RTK) surveying. This, if anything, is the one area where carrier phase surveyors may notice an improvement since SA was removed. RTK relies on transmitting the carrier phase observations from one receiver to the other, usually from the reference receiver to the mobile user, in a similar way to the DGPS principle. Just as in DGPS, this transmission takes a finite amount of time, perhaps a few seconds, with the result that the post-processed RTK position solutions are not, in fact, real-time—they can lag by a few seconds. For many low dynamic users, this sort of delay is quite satisfactory. However, there are some users who need genuine real-time performance. The approach to providing this type of performance necessarily involves a prediction of the reference station data, based on the previous epoch(s) and an observed rate of change of those measurments. Again, just as in DGPS, there is a point at which the age of the previous measurements becomes such that the predictions are not as accurate as the real-time corrections. Under SA, the result was that a few centimetres of error could be attributed to errors in the predictions. Of course, now that SA is no longer with us, such real-time systems may no longer suffer from this effect, and RTK surveyors could see an improvement of one or two centimetres as result. Of course, the post-processed solutions, which lag real-time by a few seconds, would not see this improvement, as they were always immune to the effects of SA.

Conclusions
So, in summary, the removal of the SA degradation by the US operators of GPS is not expected to have a huge impact on surveying users. The most significant benefit will be seen by stand-alone users and, to some extent, by users reliant on a communications link for DGPS or RTK GPS surveying. There are those within Europe who would reason that the removal of Selective Availability was brought about in response to the European developments of Galileo. This may be true, but regardless of the cause and process, we should all welcome the demise of Selective Availability. It has been long overdue.

Dr. Terry Moore is Reader (Associate Professor) in Satellite Navigation and Deputy Director of the Institute of Engineering Surveying and Space Geodesy at the University of Nottingham. Dr. Chris Hill is the Senior Research Fellow of the Institute of Engineering Surveying and Space Geodesy at the University of Nottingham. This article was first published in Surveying World, Issue 5, Volume 8, July/August 2000. Figure 1. Typical GPS accuracy under Selective Availability Figure 2. Stand-alone GPS accuracy post-SA Figure 3. Typical DGPS accuracy

PORTNEY'S CORNER
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A downed navigator departs from a site marked by a star in a lake region shown in Figure 1 and proceeds to the local town of Topologee Figure 2. Can he successfully cross each bridge in Topologee without repeating his path? He is rescued and brought to a site somewhere on Earth, depicted in Figure 3, where he proceeds to walk one mile south, one mile west, and one mile north, ending back at the site. As a navigator, he is not astonished. All distance references are in nautical miles abbreviated nmi. Can the bridges of Topologee be crossed only once to complete a circuit? Where was the navigator when he left his site marked by a star in the lake region (keep the right side of the figure covered); could he cross each bridge only once without repeating the circuit; where was the final site? A: On Land; no; at the North Pole. B: On land; yes; at the intersections of the Tropic of Cancer or Tropic of Capricorn and any meridian. C: On a lake; yes; at the intersection of the equator and the Greenwich meridian D: On a lake; no; at the North Pole and near the South Pole

The reader becomes acquainted with the theories of topology in solving these three scenarios. In the first scenario the navigator is on a lake (a closed curve). One is in or on a closed curve if it takes an odd number of crossings to be out of the closed curve. In this case it takes three crossings.

In the second scenario the navigator must cross nine bridges without repeating a crossing. Use your finger or pencil to trace your path. It is not possible to complete this circuit without repeating a crossing. We will demonstrate this impossibility by examining the diagram that is depicted in Figure 4.

We will use an example with seven bridges (equivalent for path logic). The key to solving this problem is attributed to Euler the father of topology. He created a network diagram to analyze the path logic. He used points (vertices) to convey land regions and arcs to convey bridges connecting the land regions.

He discovered that if a vertex had an odd number of joining arcs (referred to as an odd vertex) it could be a starting or ending point of a path once reached that could permit only one departure and one return without repeating the path. This was first noted in the famous “Bridges of Konigsberg “ paradox that Euler solved.

In Figure 4, we use a seven bridge configuration and its simplified equivalent to illustrate the path logic. We find that each of the four vertices have a convergence of three arcs, According to Euler’s theorem, when a network has more than two vertices, each with an odd number of arcs, there is no continuous path from start to the completion of the circuit. A network that can be crossed by a singular path through each arc without repeating is an Euler path. When a network has two or less vertices with an odd number of arcs, it contains at least one Euler path.

There are two cases where the navigator returns to his site by traveling the path of one nmi south, one nmi. west and one nmi. north. One site is at the North Pole shown in Figure 5 and the other, very close to the South Pole, is shown Figure 6. In Figure 5, both AB and CA are arcs of meridians (or great circles) where an arc minute is equal to 1 nmi. Arc BC is along a small circle (rhumb line). The property of the Earth, which we assume as a perfect sphere (for simplicity), that allows the return of the navigator to his origin is its sphericity. On a sphere the meridians converge at the poles. The small circles of latitude decrease in circumference as a function of the cosine of latitude as we approach the poles.

In Figure 6 let point A be the other site. The navigator proceeds one nmi. south from point A to point B along the arc of a meridian. He then proceeds one nmi. west along the small circle BCB returning to the arc of the meridian. He then proceeds one nmi. north along BA to return to his site. We know the circumference of the small circle BCB to be one nmi. We also know that the the small circle contains 360 degrees with each degree for this unknown latitude equal to 1 nmi./ 360 degrees. Therefore, a degree at this unknown latitude is equal to 0.0027777 nmi. We now can determine the latitude for this small circle. The length of a degree of longitude difference is equal to the cos latitude X 60 nmi. Thus arc cos lat. = 0.0027777(1/60) = 0.0000462 with latitude = 89.997348 degrees S. Therefore the latitude of the site at A is one nmi north of point B. One nmi. is 1 arc min which is 1/ 60 of a degree or 0.0166666 degrees places the latitude of point A at 89.980681 degrees S. The site is then 0.019319 (90.000000 - 89.980681) degrees north of the South Pole which is 1.15914 nmi above the South Pole.

Note that the site can be located anywhere along the upper small circle AD of latitude 89.980681degrees S.

A SPECIAL REPORT: ION GPS 2000

Plenary Panel Report: Where We Stand
Pamela Fromhertz, GPS 2000 Technical Track Chair
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Mr. Greg Finley, Director of the Interagency GPS Executive Board’s Secretariat, moderated a panel of individuals selected for their knowledge of GPS and GNSS issues. After brief remarks from the panel, which consisted of Mr. Charlie Trimble, Dr. Scott Pace, Colonel Doug Loverro, Mr. Lyn Dutton, and Ambassador Schoettler, a number of questions were fielded on a range of subjects as diverse as potential interference to GPS from UWB (Ultra Wide Band) technologies, and the possible merits of a National Program Office.

The panel reiterated the need to send a political message in conjunction with the technical developments of GPS, worldwide. The need to regulate UWB was the key message by the panelists. Without such regulation, UWB could potentially create interference problems with GPS and other telecommunications devices. Charlie Trimble indicated that the political arena to promote a new technology such as UWB could in fact create a threat to GPS and telecommunications without regulation. He indicated that developers of such technologies are naive in their understanding of the effects such deregulation could pose.

Mr. Dutton discussed the reasons behind the development of Galileo and indicated that the primary goal is interoperability and compatibility with GPS with the addition of a communication system for navigation.

The other panelists indicated that Galileo could offer such benefits as redundancy and integrity to GPS. Charlie Trimble didn’t think building receivers would be so difficult since that was accomplished with GLONASS, which was not supposed to be compatible. Scott Pace indicated that there were still concerns over how the European Union (EU) planned to utilize public-private partnerships in the development and implementation of Galileo. It was also noted that the United States battled the issue on user fees, recognizing that they were counterproductive. Mr. Dutton’s response was “they meet in rooms with red carpets” and the issue had not been resolved within the EU.

Colonel Loverro summarized where we are and where we need to be going by recognizing that by 2050 there will be more than one space radio navigation system. If there is one standard, there will be tremendous benefits for the world.

Sixteen-Year-Old Wins Best Presentation Award
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Casey Miller is perhaps the youngest author to present at ION GPS and win a Best Presentation Award for his paper, “A Novel GPS-Based Training Device to Improve Track and Cross-Country Training Effectiveness,” at this year’s ION GPS conference in Salt Lake City. Casey has been interested in integrating GPS receivers with physiological sensors for applications involving outdoor athletic conditioning, training, and analysis. Casey explains that in the world of sports, there is a constant effort to find more effective methods for training athletes. His paper presents the first phase in developing a novel GPS-based training device to help monitor the training progress of track and cross-country runners. The idea is that if a runner’s velocity can be compared to his or her heart rate and the runner’s perception of work, then workouts can be run more effectively. Monitoring position and velocity continuously is accomplished by using a GPS receiver with memory capabilities. Casey’s paper presents a prototype system using an Ashtech Z-Surveyor and a Polar heart rate monitoring system. In order to determine the runner’s velocity and heart rate, the runner wears a fanny pack containing the GPS receiver, a helmet holding a small GPS antenna, and a Polar heart monitoring system.The GPS receiver data (after corrected using Differential GPS) and heart rate data are post processed and correlated to determine the runner’s performance. The results are promising and clearly show how correlating a runner’s heart rate directly with his position and velocity gives coaches critical training information. Phase two involves miniturizing the system to transmit GPS and heart rate data in real time.

ION GPS 2000 Best Presentation Awards

Session A1: Geodesy, Engineering & Deformation Monitoring High Accuracy Deformation Monitoring Via Multipath Mitigation by Day-To- Day Correlation Analysis: R.S. Radovanovic, The University of Calgary, Canada. Session B1: Carrier-Phase Positioning & Ambiguity Resolution Multi-Base RTK Positioning Using Virtual Reference Stations: A. Bücherl, H. Landau, C. Pagels, U. Vollath, B. Wagner, Spectra Precision Terrasat GmbH, Germany Session C1: Satellite-Based Augmentation Systems Robust Detection of Ionospheric Irregularitites: T. Walter, A. Hansen, J. Blanch, P. Enge, Stanford University; T. Mannucci, X. Pi, L. Sparks, B. Lijima, Jet Propulsion Laboratory; B. El-Arini, R. Lejeune, The MITRE Corporation; M. Hagen, E. Altshuler, R. Fries, A. Chu, Raytheon Session D1: Receiver Systems & Technology 1 GPS Watch - An Analogue Watch Including a Very Low Power GPS Receiver: P.-A. Farine, J-J. Born, J-.D. Etienne, Y. Ferri, K. Imfeld, S. Künzi,T.K. Nguyen, A. Monthéard,Y. Oesch, F. Piccini, P. Vez, J.-P. Wattenhofer, F. Wiget, E. Zellweger, R. Dinger, Asulab S.A., Research & Development Laboratories of the Swatch Group, Switzerland Session E1: Space, Control & Network Reference International GPS Service 2000 - Life Without SA: R.E. Neilan, A. Moore, IGS Central Bureau, Jet Propulsion Laboratory; T. Springer, Astronomical Institute, University of Bern, Switzerland; J. Kouba, Natural Resources of Canada; J. Ray, U.S. Naval Observatory; C. Reigber, GeoForschungsZentrum, Germany Session F1: Radio Frequency Interference Analysis of the Multipath Meter Performance in Environments with Multiple Interferers: B. Townsend, Roberton Enterprises Ltd., Canada; J. Wiebe, A. Jakab, M. Clayton,T. Murfin, NovAtel Inc., Canada Session A2: Public Safety Systems & E-911 Synergies Between Satellite Navigation and Location Services of Terrestrial Mobile Communications: G. W. Hein, B. Eissfeller, V. Oehler, J. Winkel, Institute of Geodesy and Navigation, University of FAF Munich, Germany

Session B2: Atmospheric Effects Ionospheric Scintillation Effects in the Equatorial and Auroral Regions: P. Doherty, S. Delay, C. Valladares, Boston College; J. A. Klobuchar, Innovative Solutions International Session C2: Aviation Applications European GPS Monitoring System for the RVSM Monitoring Programme: Y. Hoffmeister-Han,T. Wieneke, Aerodata, Germany Session D2: Receiver Systems & Technology 2 A Real Time Signal Quality Monitor for GPS Augmentation Systems: A.M. Mitelman, R.E. Phelts, D. Akos, S. Pullen, P. Enge, Stanford University Session E2: Timing Synchronization & Infrastructure Possibilities for GPS Time Recovery with GSM Network Assistance: J. Syrjärinne, Nokia Mobile Phones, Research and Technology Access, Finland Session F2: Spectrum Coordination and WRC Results Interference to GPS from UWB Transmitters: M. Luo, D. Akos, S. Pullen, P. Enge, Stanford University; B. Erlandson, Collins/RTCA; S. Frodge, DOT Session A3: Mining Navigation, Guidance & Machine Control Robotic Snow Cat: G.R. Opshaug, P. Enge, Stanford University Session B3: High Precision Regional DGPS Networks Testing of a Multi-Reference GPS Station Network for OTF Positioning in Brazil: L.P. Fortes, E. Cannon, G. Lachapelle, University of Calgary, Canada Session C3: Ground-Based Augmentation Systems (GBAS) Simulated Landing Performance for GLS and ILS Systems: T. Murphy, L. Anderson, N. Hien Tang; Boeing Commercial Airplane Group Session D3: Military Precision Landing Multipath Mitigation Performance of Planar GPS Adaptive Antenna Arrays for Precision Landing Ground-Stations: J. Williams, R.J. Davis, E.N. Rosario, The MITRE Corporation Session E3: GNSS Policy Issues Establishing Next Generation GPS Performance Standards: R. Conley, Overlook Systems Technologies, Inc.

Session A4: Marine Navigation & Positioning A DGPS/DGLONASS Positioning Solution for Geographic Locations with High Ionospheric Variability: M.O. Mathewson, Seatex Inc.; A. Rinnan,T. Schwenke, Navia Maritime AS, Norway Session B4: Algorithms & Methods 1 Fault-Tolerant GPS/INS Navigation System with Application to Unmanned Aerial Vehicle: L.H. Mutuel, J.L. Speyer, University of California at Los Angeles Session C4: Space Systems & Applications I Sensing Technologies for Formation Flying Spacecraft in LEO Using CDGPS and Inter-Spacecraft Communications System: C.-W. Park, Stanford University; J.P. How, Massachusetts Institute of Technology; L. Capots, Lockheed Martin Session D4: GPS — Reference & Information Fusion A Novel GPS-Based Training Device to Improve Track and Cross-Country Training Effectiveness: C. C. Miller, Carroll High School; M.M. Miller, AFIT/ENG; J. Agnew, ASC/YTA and Carroll High School Session E4: GNSS Modernization - Galileo GPS/Galileo Radio Frequency Compatibility Analysis: J. Godet, GAST/CNES, France Session A5: GIS & Mapping RiGHt: River Level Monitoring Using GPS Heighting: T. Moore, The University of Nottingham, UK; G. Close, Science Systems Space Ltd. UK; R. Moore, Institute of Hydrology, UK Session B5: Algorithms & Methods 2 Defining Pseudorange Integrity - Overbounding: B. DeCleene, Federal Aviation Administration Session C5: Space Systems & Applications 2 Real-Time GEO Orbit Determination Using TOPSTAR 3000 GPS Receiver: C. Mehlen, ALCATEL Space Industries, France; D. Laurichesse, CNES, France Session D5: Military Applications & Anti-Jam Technologies Selective GPS Jamming: B. Price, Threat Systems Management Office; J. Jetton, Scientific Research Corporation

Session E5: GNSS Modernization-GPS Compatibility of the Interplex Modulation Method with C/A and P(Y) Code Signals: P.A. Dafesh, L. Cooper, M. Partridge; The Aerospace Corporation Session F5: Attitude Determination Performance Improvement for GPS-Based Attitude Determination Systems: L. Giulicchi, European Space Agency, The Netherlands; L. Boccia, G. Di Massa, G. Amendola, University of Calabria, Italy Session A6: Agriculture Carrier-Phase Differential GPS for Control of a Tractor Towed Implement: D. M. Bevly, B. Parkinson, Stanford University Session B6: Algorithms & Methods 3 The Multipath Invariance Approach for Code Multipath Mitigation: R.E. Phelts, P. Enge; Stanford University Session C6: AVL & Asset Management A Scaleable Navigation Array of GPS, Inertial, and Dead Reckoning Sensors: J. Pfister, C. Schmalz, L. May, Darmstadt University of Technology, Institute of Flight Mechanics and Control, Germany; H-J. von der Hardt, Honewell Regelsysteme GmbH, Germany; J. Beyer, DE-Consult, Germany Session D6: Antenna Technology Automated Absolute Field Calibration of GPS Antennas in Real-Time: G. Wubbena, M. Schmitz, Geo++ GmbH, Germany, F. Menge, V. Boder, G. Seeber, Institut fur Erdmessung, Universitat Hannover, Germany Session E6: GPS Operations & Control Operational Response to an Aging Global Positioning System Constellation: J.J. Losinski; 2nd Space Operations Squadron, Schriever AFB, CO Session F6: Integrated Positioning & Navigation Systems Spacecraft Attitude Determination Using a Combination of GPS Attitude Sensor and Star Sensor Measurements: C. Arbinger, W. Enderle, German Aerospace Center (DLR) German Space Operations Center

ION GPS 2000 Kepler Award Winner
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Dr. Per Enge, past ION president, with Kepler Award. Congratulations!

Dr. Per Enge of Stanford University was lauded for his continued contributions in the field of radio-navigation, ranging from Loran-C, radio-beacons for DGPS broadcasts, GPS augmentations and guidance of students.

The Kepler Award, given annually for sustained and significant contributions to satellite navigation, was presented by then Satellite Division Chair Ron Hatch at the ION GPS 2000 conference held in Salt Lake City, Utah, Sept 19-22.

Dr. Enge holds seven patents in radio-navigation and communications, his latest regarding multipath equalization. Two others that propose innovative receivers for LEO (low earth orbiting) and multi-tone DGPS are on file. These inventions represent important enabling technologies of the augmented GPS.

He invented a signaling scheme for Loran-C, which provides a communication capacity without degrading Loran’s traditional navigation function. This system is today a key part of the Eurofix system, which creates synergy between Loran and GPS.

Starting in 1985, Enge was funded by the U.S. Coast Guard to develop a DGPS broadcast using marine radiobeacons. As part of this effort, he designed the DGPS/radiobeacon signal and showed that this system would be a cost-effective way to deliver high accuracy to marine users. He holds two patents in this area and this work has substantially increased the robustness of the radiobeacon DGPS, now being used worldwide. Enge would be anxious to share credit with his colleagues, but he has been the spearhead for much of this innovation.

Since 1991, the Federal Aviation Administration has funded him to develop WAAS and LAAS. As part of this effort, he and Dr. A.J. Van Dierendonck led the design of the WAAS signal and data format. Enge’s research group at Stanford University was the first to conduct real time flight trials using this data format. Additionally, Enge led the development of the clock and ephemeris algorithms for one of the development systems that the FAA used to evaluate WAAS accuracy.

Enge has written more than 60 articles and papers on radio navigation and communication; more than twenty of these have appeared in refereed journals. His papers have received “Best of Session” awards at ION conferences. Enge is currently associate editor of NAVIGATION, the journal of the Institute of Navigation and is on the editorial board of the proceedings of the IEEE.

Satellite Division program and track chairs (not all pictured) (from left to right): Pamela Fromhertz, Dr. Terry Moore, Ms. Sally Frodge, Mr. Larry Hothem, Dr. Anthea Coster, and Dr. Naser El-Sheimy.

From left to right: Plenary Session Moderator Greg Finley, Plenary Panel Member Scott Pace, General Chair Sally Frodge, and Plenary Panel Member Charles Trimble.

Special thanks to the many ION GPS 2000 exhibitors that provided product demonstrations and that sponsored special events: Trimble & Spectra Precision Surveying NovAtel Inc. Leica Geosystems The ION would also like to thank the sponsors of this year’s Show Daily: NovAtel Inc. Javad Navigation Systems and Topcon Positioning Systems

(Clockwise from upper left) Program Chair Larry Hothem with General Chair Sally Frodge. Outgoing Satellite Division Chair Ron Hatch. Incoming Satellite Division Chair, Dr. Penina Axelrad, with ION President Karen Van Dyke. Incoming and outgoing International Representatives to the Satellite Division Executive Committee, Lyn Dutton and Dr. Güenter Hein, respectively.

GPS and Ultra-Wideband
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Comments to the Federal Communications Commission (FCC) Notice of Proposed Rulemaking (NPRM) on ultra-wideband (UWB) were submitted by September 12, 2000 and the reply comment period closed out October 27, 2000. Data from testing efforts was submitted by October 30, 2000, although many, including the National Telecommunications and Information Administration (NTIA), have called for an extension to this deadline. NTIA has requested an extension until February 2001, but others express that a fuller testing effort must be accomplished that will require additional time beyond that date.

Interference Issues
Concerns of interference were expressed by not only the GPS community but also some within the telecommunications community. Many submissions within the docket reflect rising concern over the potential for harmful interference to existing services that include aviation safety-of-life, E-911, and concern that insufficient testing has been accomplished by the government, including the FCC.

Should UWB be granted Part 15 authority, these devices could be mass marketed with no license required. The increasing concern is that without sufficient testing to determine the potential for interference (or not) the proliferation of UWB devices could cause widespread interference problems. If these devices are under Part 15 – i.e., unlicensed — then there would be no effective way to mitigate the problem through recall or other means.

Further information can be obtained by inspecting the docket, available on-line from the FCC.

Notes
1. NPRM on “Revision of Part 15 of the Commission’s Rules Regarding Ultra-Wideband Transmission Systems”, ET Docket No. 98-153. 2. The home page of the FCC is http://www/fcc/gov. Click on “E-Filing” to go to the “FCC’s Electronic Filing and Public Access System”. Scroll down and click on the “Electronic Comment Filing System (ECFS)” and then click on “Search the ECFS System”. Double click on “Proceeding” and type in “98-153” into the box, then click on “Search for Proceedings.” The hotlink “98-153” will appear. Double click on “98-153” and then on the “Retrieve Document List”.

Nostalgia and the Analemma: One of a Series of Columns
By ION Historian Marvin May
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The study of history inevitably includes an emotional component that brings forth an element of nostalgia. Although most of us owe our livelihoods to the pursuit of high technology and are both grateful and intrigued by the convenience and prowess of modern navigation techniques, some also yearn for the “good ol’ days” when life appeared to be simpler and dependencies on machines were minimal. This widely felt nostalgic emotion is sometimes caused by a fundamental need to escape from the hustle bustle or by a survival instinct to reduce risks or perhaps due to a back to nature attitude.

I was particularly struck while attending the Institute’s 56th Annual Meeting in San Diego on June 26–28, 2000. One of the sessions co-chaired by Joe Portney, was dedicated to and entitled, “The History of Navigation and Time.” In this session, there were several papers that recalled days of yesteryear in navigation, but one paper particularly fascinated me. This paper was entitled “Resurrecting the Analemma” by Samuel G. Shaw. There were several nostalgic or contrarian themes to this paper which appealed to me. The paper describes a simple celestial method of determining position at sea without the use of calculators, computers, nautical almanacs, sight reduction tables, batteries or even the Internet. The last, although not presently considered a standard navigation tool, is certainly a major contributor to today’s frenetic pace, and its absence is particularly noted since Samuel Shaw’s day job involves the deployment of intranet applications as an employee of Cisco Systems.

What the celestial method described in the paper does require is a chronometer, a sextant, some paper and pencils, a slide rule and an analemma. To immerse yourself in the nostalgic spirit, the chronometer should be an old time mechanical windup made some time between Benjamin Harrison’s death and the launch of Sputnik I. The sextant should also be a vintage tool— perhaps one of the many described in Peter Ifland’s illustrative “Taking the Stars.” The opportunity to use my old, cherished Keuffel and Esser wooden slide rule was an added bonus to the technique. After foraging my basement and pushing past my eight track cassette stereo, manual typewriter and carburetor tuneup kit, I reacquainted myself with the C, D, and S scales, grateful that I didn’t have to remember the utility of some of the more esoteric slide rule scales.

That leaves us with the dilemma of knowing what an analemma is. The analemma is a figure eight shaped graphic representation of the earth’s annual path around the sun. Its mathematical shape can be derived from analyzing the relationship between the axis of rotation of the earth itself in relation to the axis of revolution about the sun and accounting for the ellipticity of the earth’s annual path about the sun. The picture of the sun’s analemma shown in the diagram below is taken from a 3-inch by 5- inch laminated card. In the first half of the twentieth century, the analemma was a standard feature on any globe or map of the world. In recent years, however, the analemma has all but disappeared. The analemma is used to approximate the sun’s value of declination that is normally found in a nautical almanac. The value of the Equation of Time is also obtained from the analemma and is used to determine the Greenwich Hour Angle (GHA)of the sun.

As with classical celestial navigation position techniques, knowing the declination and GHA (along with time) of two celestial bodies allows one to know their subpoints. With the knowledge of the sub-points and an altitude measurement to each of the celestial bodies, one can develop lines of position which intersect at the desired position. As detailed in Shaw’s paper, a traditional morning line sun altitude measurement along with a local apparent noon measurement of the sun, can be adequate to achieve the necessary separation of subpoints. The analemma is used to obtain the declination of the sun (equivalent to latitude for the local apparent noon case) and the Equation of Time which yields the GHA of the sun. From there, relatively common methods—all achievable with our low tech tools—of correcting the sextant measurements, developing lines of position, advancing the lines of position, plotting the lines of position, and reading off a fix can be employed.

Postscript. The best way to learn more about this ultra low tech technique is to read the aforementioned paper that also references the following Internet sites: www.analemma.com for interesting pictures and explanations of the analemma, and www. taswegian.com for slide rule information. I also note that EBAY’s Internet site often has a varied selection of sextants and chronometers for sale. My thanks to Samuel Shaw for writing the article and for giving me an analemma, which is also available from Dropzone Press, San Francisco, Ca.

Annual Award Nominations Open
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Members are encouraged to submit nominations for one or more of the following annual awards given by the ION for excellence in navigation.

• Superior Achievement Award — for individuals making outstanding contributions to the advancement of navigation.
• Captain P. V.H.Weems Award — for continuing contributions to the art and science of navigation.
• Norman P. Hays Award — for outstanding encouragement, inspiration and support leading to the advancement of navigation.
• Thomas L.Thurlow Award — for outstanding contributions to the science of navigation.
• Tycho Brahe Award — for outstanding achievement in space navigation.
• Early Achievement Award — for an individual early in his or her career who has made an outstanding achievement in the art and science of navigation.

The awards and accompanying engraved bronze plaques will be presented at ION’s 57th Annual Meeting, June 11-13, 2001, in Albuquerque, New Mexico. The 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 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 journal, NAVIGATION, will be honored at the meeting.

Fellow Nominations Being Accepted
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The Institute of Navigation is currently accepting nominations for the election of Fellows. Election to Fellow Membership recognizes the distinguished contribution of ION members to the advancement of the technology, management, practice and teaching, of the arts and sciences of navigation, and/or for lifetime contributions to the Institute.

Former members of the ION who are not currently active members of the organization may be elected to non-voting Fellow Membership. A limited number of individuals may be accepted as posthumous Fellow Members.

Members of other National Institutes of Navigation who are qualified by their accomplishments for recognition as a Fellow Member are eligible for election to Honorary Fellow Membership.

Nominations may be submitted by currently active ION members. All nominations must be in conformance with ION nomination guidelines as outlined on the nomination form. Nominations must include a brief biography and proposed citation. Details of the nomination process and nomination forms are available on the ION Web site at www.ion.org. Nominations must be received by December 15, 2000 to qualify.

Address correspondence to Fellow Selections Committee, The Institute of Navigation, 1800 Diagonal Road, Suite 480, Alexandria, Virginia 22314, fax: 703-683-7105, e-mail: membership@ion.org.

Satellite Division Call for Proposals Due December 15
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The Satellite Division of the ION in cooperation with the National Aeronautics Association (NAA) is soliciting colleges and universities to adapt a Commercial Off The Shelf (COTS) GPS system that will be used to establish aviation speed record attempts for a closed course.

Copies of the Request For Proposals can be obtained on the ION Web site at www.ion.org.

The ION is asking universities to indicate their intent to submit a proposal along with any questions, exceptions taken, discrepancies and/or suggestions for improvements in the referenced documents by e-mail to Carl Andren at candren@ion.org by no later than December 15, 2000. Any modifications to these documents as a result of this feedback will be transmitted to all responding parties by e-mail no later than December 22, 2000. It is the intent of the ION to announce the award by January 31, 2001.

Another Block IIR Launched
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At 12:14:02 EST on November 10, the fifth GPS block IIR satellite was launched. Designated SVN41, PRN14, the satellite has been placed into plane F, slot 1 of the GPS constellation. The next launch is tentatively scheduled for January 30, 2001. The Launch was dedicated to America’s veterans in commemoration of Veterans’ Day. The POW MIA insignia can be seen on the launch patch.

USAF Awards GPS III Contract
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The Boeing Company, Seal Beach, Calif. and Lockheed Martin Space Systems Company, Sunnyvale, Calif., are each being awarded a $16 million firm-fixed-price contract for architecture studies in support of the Global Positioning System III program.

These studies represent the first phase in the development of the global positioning system to support military and civilian users for FY 2010 through FY 2030. These analyses will survey emerging technologies and refine system architectures to develop the technical and programmatic planning to enter one or more concept architectures into Program Definition and Risk Reduction. Expected contract completion date is Nov. 2, 2001.

Russians Replenish GLONASS
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Russia shored up its GLONASS system with the launch from the Baikonur launch facility in Kazakstan of three satellites October 13. The new satellites (783/Kosmos 2374, 787/ Kosmos 2375 and 788/Kosmos 2376) will be placed into slots 18/17/24. By the end of September, only eight satellites were operational. The addition of three more bring the total to eleven, which is considered the minimum necessary to operate the network.

In Memoriam
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Colin Hugh McIntosh, the ION’s first president and well-known air transport consultant in Washington D.C., died September 1, 2000. Since establishing his consulting practice in 1952, he has been retained by many air carriers both for internal studies and assistance in economic proceedings before the Civil Aeronautics Board. Additionally, he has been retained by investment firms, government agencies, aircraft manufacturers, and other firms with interests in air transport. Mr. McIntosh temporarily suspended private practice to assume responsibility for preparing the National Civil Air Policy report requested by President Eisenhower. From 1948 to 1952, McIntosh was vice president of operations of Allegheny Airlines (now U.S. Air). He previously worked for American Airlines as chief navigator. While with American, he wrote Radio Navigation for Pilots (adopted as an official armed forces training manual) and Long Range Flight, one of the first texts on long distance aircraft operations. Mr. McIntosh, who was born in Malden, Massachusetts, in 1908, died in Palm Beach, Florida. He was a graduate, cum laude, of Williams College.

Milton Trageser, 1928–2000, former director of Draper’s Apollo program and a 38-year employee of Draper Laboratory, died October 7 at his home in Winchester, Mass. Milton was the 1981 Thurlow Award recipient for his work in the performance of theoretical analyses and system designs on a number of important inertial navigation systems, and his direction of the design of the inertial navigation system for Apollo.