Message-Id: Date: Fri, 17 Nov 2000 16:59:53 -0800 To: igsmail@igscb.jpl.nasa.gov From: "Ruth E. Neilan" Subject: [IGSMAIL-3105]: OSLO IGS Network-COST 716 Workshop Summary Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 17 Nov 16:57:13 PST 2000 Message Number 3105 ****************************************************************************** Author: Ruth Neilan Dear colleagues, This message contains a brief summary of the Oslo Workshop, jointly conducted between the IGS and the COST 716 that was held in July. For reference, the agenda of the IGS Workshop portion is also appended at the end of the summary and numerous web site links are included as a resource. The recommendations stemming from this important workshop are contained in a separate subsequent message. Workshop participants can be viewed in the Extended Abstracts book referred to below. Many thanks to those of you who made this workshop such a success - with sincere regards, Ruth Summary IGS Network Workshop Oslo, Norway 10-15 July 2000 The second major IGS Network Workshop was held in Oslo, Norway, July 10-14, 2000. The purpose of this workshop was to focus on aspects of the network targeted at improving the infrastructure and network operations in support of the quality and timeliness of IGS products. Dr. Angelyn Moore, IGS Network Coordinator and Deputy Director of the IGS Central Bureau in JPL Pasadena did an exceptional job convening this workshop, which was considered a great success by all who attended. The local host and logistics were managed excellently by Dr. Hans-Peter Plag of Statens Kartverk, the Norwegian Mapping Authority (NMA). Much appreciation is expressed to Bjorn Engen, Director of Geodesy Division at NMA, and his staff, to note a few: Oddgeir Kristiansen, Rune Hanssen, and Svein Rekkedal among others. Bjorn Engen is one of two IGS Network Representatives to the Governing Board, thus it was a good opportunity to organize this meeting with his support. The venue for the workshop was at the beautiful Soria Moria Hotel on a hill overlooking Oslo. The atmosphere enjoyed by old and new colleagues will not be forgotten. This was the first occasion that the IGS Network workshop was convened as a multi-disciplinary meeting. On Monday and Tuesday, July 10 and 11, the workshop was devoted to 'COST Action 716'. COST stands for 'European Cooperation in the Field of Scientific and Technical Research'. Action 716 is 'Exploitation of Ground Based GPS For Climate And Numerical Weather Prediction Applications'. COST is a framework for scientific and technical cooperation, allowing the co-ordination of national research on a European level. COST Actions consist of basic pre-competitive research as well as activities that serve public utility. The main objective of 716 is assessment on an international scale of the operational potential for exploiting ground based GPS networks to provide near real time observations for numerical weather prediction and climate applications. In parallel, the IGS has a dedicated troposphere working group estimating total zenith path delays (ZPD) and precipitable water vapor (PWV) at a number of the IGS stations. Also, a number of the IGS agencies and their networks have either implemented or are moving towards real-time processing activities, many pursuing similar applications in terms of groundbased meteorology. The synergy for having a joint workshop was quite evident. A joint COST/IGS session was planned for Wednesday, July 12, followed by the IGS Network Workshop focusing on detailed IGS infrastructure issues July 13 & 14. The detailed agendas can still be found at http://www.gdiv.statkart.no/igsworkshop/ An excellent book of extended abstracts prepared by the Norwegian Mapping Authority is available: http://www.gdiv.statkart.no/igsworkshop/book/ This is the first IGS workshop where a commercial publisher will actually handle the proceedings. This will be a joint, peer reviewed proceedings published by Elsevier and it will be available sometime early in 2001. A number of copies have been secured by the IGS for distribution and archival. However, copies will be available for sale directly from Elsevier, more information will be provided in the future. Executive Summary The IGS Network Workshop focused on a number of key issues facing the IGS in terms of moving products closer to real-time delivery. The IGS has been generating an unofficial product called the Ultra Rapid, which is delivered twice daily from the analysis centers to prospective users. This requires hourly retrieval of data files and twice daily processing of the products. In order to make these Ultra Rapid products and predictions available in a more reliable fashion, a number of issues must be addressed by the IGS network community. The three key issues seem to be: - hourly data operations and reliability, - the availability of hourly data from the data centers, and in particular the global data centers, - as the IGS network moves closer to supporting real-time applications, development of an exchange format for data from the different sites around the world is needed as a standard It's very clear that many of the participating agencies within the IGS already run regional or national networks in real-time, some at high rate (1second sampling), and with essentially no latency in data streaming (less than a few seconds). If the IGS is to support these kind of applications from a global level, there must be an international standard which the IGS can develop, adopt, and promote to realize a subset of the global infrastructure which supports real-time, high reliability applications. COST Workshop Summary The COST Workshop opened Monday morning with a description of the COST Action. These COSTS are based on inter-governmental agreements between 32 countries to initiate research activities within Europe. This is open to industry, natural research centers, universities, and other agencies to create scientific networks and applications. Currently, there are more than 70 initiatives within COST and over 200 COST Actions at the moment. COST 716, the focus of this workshop, was under the meteorology initiative, of which there are currently seven with three new ones being planned. There are four working groups in this COST Action 716, which will be meeting over the next few days of the workshop. This COST 716 was initiated in September of 1999 and there are four working groups, 1) To produce the state-of-the-art product requirements, 2) A demonstration of these, 3) Working group on applications and developing applications, and 4) What the plans are for those applications. The COST home page is here: http://www.belspo.be/cost/ Action 716: http://www.oso.chalmers.se/Geo/cost716.html Gunnar Elgered from Sweden chairs COST 716. He stated that the primary purpose of 716 was to study the combined affect of the GPS errors and atmospheric errors and see how they de-correlate with distance and to assess how the GPS observations can be utilized for operational meteorology. Mark Higgins, Representative of the UK Meteorology office, discussed the applications of GPS from studies that they have been conducting throughout Britain. The primary message from his talk was meteorological offices use many sensors worldwide, but the potential for tracking the very rapid changes with GPS is what could prove most useful. Key questions such as "When will it start to rain over Wimbledon?" and also how can GPS improve timing for forecast predictions are of most interest. He also stated that they'd like to have, within an hour and one-half after the observations are made, information that a local forecast office could use for the next 36 hours. This information would be most useful for the first 12 hours. He showed some interesting cases where GPS had seemed to work quite well and other cases where it clearly did not. Most of their models are using the total path delay and some of the questions that he summarized, representative of subsequent discussions as well, were: where, how and when to use surface pressure observations? what are the height correction schemes for GPS? how do the horizontal observation errors correlate with ground based GPS, what is the height variation of g, etc. They also noted that they'd really like to get the climate users on board and engaged with this activity. Network Workshop Summary The overview for the workshop began with an introduction by Gunnar Elgered, who went over the details of COST 716 as stated above. Jim Zumberge, from JPL, followed with a presentation on the effect of the removal of selective availability SA and the way in which satellite clocks can be handled within the IGS. With the removal of SA, intentional frequency dithering of GPS satellite clocks, it now seemed possible to do a combined predicted clock as well as presenting the possibility for predicting a real-time clock to a much greater accuracy than previously available. With SA on, the transmitter clocks would indicate excursions of roughly 20 centimeters per second (rms slope of the transmitter clocks), with tens of centimeter variations over a few hours. With the removal of SA, studies indicate an improvement to ~a millimeter per second variation. He indicated that clocks based on the 30second GPS data could be good to ~4mm, and for 10second data to the ~2mm levels. The next aspect within the IGS workshop was a focus on the IGS Rapid-Ultra Rapid products. Gerd Gendt from GFZ in Potsdam, talked about the improvement of the Ultra Rapid (sub-daily) over the Rapid (daily) and how much improvement could be made for the Ultra vs. the Rapid with better network configuration and performance. He was recommending to shorten the time from the current 12 hour data sets, which the analysis centers are using, to six hours, submitting orbit estimates every 4 hours instead of every 12. The greatest difficulty that most analysis centers are having in terms of achieving these objectives is the availability of data and also the reliability of the data centers. He suggested that some kind of real-time integrity or quality monitoring would be preferred. Hans van der Marel from Delft presented recommendations on operations for GPS ground based meteorology and also discussed the NRT or Near Real Time networks within Europe, planned to support upcoming demonstrations within COST 716. An NRT demonstration is planned for February 2001, which will be the first time that the output from the GPS ground network will be input into the analysis for numerical weather prediction (NWP). The NRT networks within Europe participating in this are the Magic Network, the Gasp and the Alpine Network. He stated that the NRT reference network will depend heavily on IGS and EUREF networks and that they will be using IGS Ultra products and predictions. Throughout the remainder of the day there were presentations from Stick Ware of UCAR describing SUOMI Net, a project to install over 100 receivers at different universities, primarily located in the U.S for the purpose of atmospheric studies. Jens Wickert described the CHAMP GPS ground network and applications from CHAMP for space-based, air ground based meteorology. Ron Muellerschoen from JPL presented an interesting result on real-time network being operated out of JPL for real-time, continuous orbits and positioning which resulted in ~30-40 centimeter orbits. Tim Springer, the IGS Analysis Center Coordinator, went on to describe the current status of products within the IGS. The remainder of the day and the following two days focused more on detail in terms of routines for data validation, quality checking, what the directory structure should be for hourly data, how to have similar directory structures implemented at the regional, operational, and global data centers. The discussion on various communications schemes, VSAT, internet, wireless also raised discussions of LDM, a system developed by UniData Corp. in association with UCAR for the distribution of primarily atmospheric data. There was an extended discussion on data formats for real-time data as it became evident that there are currently as many as eight different formats being used by participants within the IGS. A working group was formed to discuss the formats and to make a recommendation for an internationally accepted standard or format to be used by the IGS. Some of the binary formats include: the native format coming out of the receivers; UNAVCO's proposal of BINEX; Norwegian Mapping Authority's SATREF network format called RIBEX; Delft is using a type of binary RINEX, NCBI; GFZ reported on a type of binary format which is based Turbo-binary compressed (used by GFZ and JPL for CHAMP network operations, as well as a GFZ-BINEX format) and JPL is using a format known as 'SOC'. There was a recommendation that the IGS investigate the RTCM format utilized by most of the real time corrections, navigation and RTK applications within the broader GPS user community. There were descriptions from various regional operators describing activities, e.g., Bob Twilley from Australia, Ludwig Combrinck from South Africa, and from applications e.g., Susan Skone from Calgary using the IGS network to conduct ionospheric research. Bruce Schupler from Honeywell gave a very interesting presentation on frequency phase center responses to radomes and calibration of antennas. He also considered the impact of the new GPS civil frequency at 1175 MhZ, which may require a new band pass filter on the antennas. Professor Gu Guohua gave an interesting description of the CMONOC network within China - the 'Crustal Motion Observation Network of China' which includes 25 permanent continuous fiducial stations, 56 basic stations and 1000 regional stations, the latter operated just occasionally in a campaign style mode. He described that they have satellite communications at most of the 25 stations and that their data center has the possibility to store 81 GB on line with 16 workstations and a number of IBM servers. CMONOC has proposed to the IGS to become a data center, a mirror site for the Central Bureau information system, and, as soon as practical, become an analysis center for regional analysis within the IGS. For the data centers, Carey Noll showed that currently 50% of the hourly files are delivered within 15 minutes. This was met with the recommendation that hourly files should be more reliable, more accessible, and their latency should be no more than 10-15 minutes after the hour. There was also the recommendation that the broadcast ephemeris be added to the hourly data. Tom Herring and Tim Springer presented results that used the time series of the GPS stations to assess current performance and quality, noting some particular difficulties and problems with stations that would not be detected by the currently available programs, such as the TEQC of UNAVCO. Tom showed an approach developed at MIT of using SNRs and the stability of Lc phase rms as an indicator of station performance over time. See his website for examples and tools: http://www-gpsg.mit.edu/ A contest was held for the best poster presentation with the award being a donated receiver from Ashtech. A committee comprised of 3 members from COST and 3 from IGS was established to review each poster and met to agree on the best deserving poster. The winner was Jan Dousa, and co-author Leos Mervart from the Research Institute of Geodesy, Topography and Cartography in the Czech Republic, for their poster 'On Hourly Orbit Determination'. Many thanks to Ashtech for their generous contribution and engaged support of the IGS. The general workshop concluded on Friday, July 14 at noon. A summary session was held in the afternoon present per IGS tradition attended by the Conveners, Central Bureau, and Governing Board members. The key recommendations stemming from the summary session are in a separate message. This concludes the brief summary of the highlights from the IGS Network Workshop 2000. We encourage interested people to obtain a copy of the proceedings that will go into much more depth on all of the issues discussed above. Regards, Ruth Neilan IGS Central Bureau +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Wednesday, 12 July 2000 Opening Remarks Welcome from Statens Kartverk: Bjorn Engen 9:00-9:25 Welcome from the IGS: (Ruth Neilan for)Christoph Reigber Opening Remarks: Angelyn Moore Practical Details: Hans-Peter Plag Real-time Analysis Center Issues, Now and Future: G. Gendt, J. Zumberge 9:25-9:45 An Overview of COST Action 716 G. Elgered (Extended abstract) 9:45-10:05 Position Paper G. Gendt and J. Zumberge 10:05-10:25 COST and the IGS (Extended H. VanderMarel abstract) 10:25-10:45 SuomiNet: A GPS Network for R. Ware Real-time Atmospheric Sensing 10:45-11:00 break 11:00-11:20 Occultation requirements (Extended J. Wickert abstract) 11:20-11:40 JPL real-time analysis software R. Muellerschoen 11:40-12:00 Ultrarapid products -- quality T. Springer dependence on network performance 12:00-12:20 IGS Hourly Data and Products for P. Fang Near Realtime GPS/Met Applications 12:20-12:40 Panel discussion Session conveners & authors 12:45-1400 Lunch Network Requirements: Caissy, Gurtner 14:10-14:30 Position paper M. Caissy and W. Gurtner The Western Canada Deformation 14:30-14:50 Array: Continuous GPS Network M. Schmidt Operations at PGC 14:50-15:10 JPL and UNAVCO Network operations D. Stowers in light of LEO ops 15:10-15:30 Multipurpose GNSS network R. Hanssen operations 15:30-16:00 break (+ finalize poster setup?) 16:00-16:20 Real-time Data Streaming from GPS M. Jackson, C. Meertens, Networks and C. Rocken 16:20-16:40 Data Formats (Extended abstract) A. Moore, summarizing input from several groups 16:40-17:00 Panel discussion Session conveners & authors 17:00-18:00 Poster viewing + icebreaker Thursday, 13 July 2000 ------------------------- Regional operations & equipment issues: M. Chin, L Combrinck 9:20-9:40 Position paper M. Chin, L. Combrinck The Response of GPS Antennas -- How 9:40-10:00 design, environment, and frequency B. Schupler affect what you see GPS Receiver Tracking Performance 10:00-10:20 under Ionospheric Scintillation S. Skone Conditions (Extended abstract) 10:20-10:40 GPS Site Continuity A. Niell 10:40-11:00 break EUREF, The Regional Densification 11:00-11:20 of the IGS in Europe (Extended C. Bruyninx abstract) 11:20-11:40 The Australian Regional GPS Network B. Twilley 11:40-12:00 Progress in the Crustal Movement G. Gu et. al. Observation Network of China 12:00-12:30 Panel discussion Session conveners & authors 12:45-14:00 Lunch 14:00-14:30 Poster + exhibit viewing Data systems: C. Noll 14:30-14:50 Data flow/Backup (Extended C. Noll abstract) 14:50-15:10 Hourly data flow H. Habrich and D. Stowers 15:10-15:30 IGLOS-PP (GLONASS Pilot Project) W. Gurtner (Extended abstract) 15:30-16:00 break 16:00-16:20 IGS Support to LEO Missions -- data T. Yunck systems 16:20-16:40 CHAMP-ISDC - The IT Project for B. Ritschel Satellite Missions 16:40-17:00 UNAVCO Community GPS Seamless C. Meertens, F. Boler, L. Archive (GSAC) Project Estey, and M. Scharber 17:00-17:30 Panel discussion Session conveners & authors 20:00 Banquet Friday, 14 July 2000 ------------------------- Quality of the IGS Network: T. Herring, T. Springer Current status of IGS station 9:20-9:40 quality feedback (Extended A. Moore abstract) 9:40-10:00 Current State of IGS Analysis: T. Herring, T. Springer Quality Assessment 10:00-10:20 Radome lessons learned J. Johansson and G. Hedling Fundamentalstations - an important 10:20-10:40 key for the combination of space W. Schluter techniques 10:40-11:00 Panel discussion Session conveners & authors 11:00-11:20 Break 11:20-12:00 Break out into working group discussions 12:00-12:25 Plenary: brief working group reports 12:25-12:40 Closing session Workshop organizers 12:45-14:00 Lunch 14:30-17:00 Wrap-up and plans Program Committee (Closed session) Poster presentations ------------------------- The IGS Global Data Center at the Carey Noll and Maurice Dube CDDIS -- an Update (Extended abstract) Roman Galas, Christoph Reigber, and H/R GPS Ground Tracking Network for Jens Wickert CHAMP Roman Galas and Wolfgang Koehler A Binary Exchange Format for GPS Data M. Schmidt, H. Dragert, W. Hill, N. New GPS Monument Design for Permanent Courtier GPS Installations in the Western Canada Deformation Array PyGPS: a GPS data processing Alexander Voinov automation package (Extended abstract) Preliminary results of processing of Zinovy Malkin, Alexander Voinov EUREF observations using non-fiducial strategy (Extended abstract) Iskander Gayazov, Maxim Keshin, GRAPE software for GPS data Alexander Fominov processing: first results of ERP determination (Extended abstract) L. Estey, C. Meertens, and D. Hunt Application of BINEX and TEQC for Real-Time Data Management O. Ruud, D. Stowers, M. Jackson, B. Perin, K. Feaux, and D. Maggert UNAVCO GPS Network Operations J. Neumeyer Th. Nischan and M. Technical solutions of GFZ global GPS Ramatschi network Matthijs van Domselaar, Yehuda Bock, Peng Fang, Paul Jamason and Michael Activities at the Scripps Orbit and Scharber Permanent Array Center (SOPAC) IGS Stations as Tectonic Tracers and G. Steblov and M. Kogan Importance of Local Densification (Extended abstract) Jan Dousa, Leos Mervart On Hourly Orbit Determination (Extended abstract) Proposal for a Binary Receiver Kees de Jong and Hans van der Marel Independent Exchange Format (Extended abstract) Real-time GPS and Glonass Integrity Kees de Jong and Hans van der Marel Monitoring and Reference Station Software (Extended abstract) J. Dow, R. Zandbergen, J. Feltens, ESA/ESOC GPS receivers. Current C. Garcia, I. Romero. status and future plans. Ensuring timely and consistent data Plag, H.-P., Kristiansen, O. delivery by automated control procedures Plag, H.-P., Kierulf, H. P.; Kristiansen, O.; Opseth, P. E.; Extended GPS site documentation Rekkedal, S. Geirsson, H., Arnadottir, T., and The Icelandic Continuous GPS Network Bergsonn, H. - ISGPS (Extended abstract) Hanssen, R. I., and Opseth, P. E. The SATREF Receiver Independent Binary Exchange Format (RIBEX) Hanssen, R. I., Halvorsen, T., and GNSS Data Integrity Monitor System Vang, P. (GDIMS) A Simple GPS Precise Point Heroux, P. and Kouba, J Positioning Interface Using IGS Orbit Products Italian GPS Network: Operational Faccia, R. activity of Centro di Geodesia Spaziale di Matera (Extended abstract)