The Space Geodesy Project
Stephen Merkowitz Space Geodesy Project Manager Code 690.2
Solar System Explora on Seminar for the Director of Science and Explora on
August 22, 2012
Dynamic Earth
8/22/2012 h p://space-geodesy.nasa.gov 2 Mo va on: Monitoring the Earth System
8/22/2012 h p://space-geodesy.nasa.gov 3 Pillar 1: Geometry and Deforma on of the Earth
u Problem and fascina on of measuring the Earth: – Everything is moving ! u Examples: – Plate mo ons – Solid Earth des (caused by Sun and Moon) – Loading phenomena (ice, ocean, atmosph.) – Earthquakes … u Con nuous monitoring is absolutely crucial.
8/22/2012 h p://space-geodesy.nasa.gov 4 Pillar 2: Earth Rota on
u Earth orienta on parameters (EOP) describe the irregulari es of the earth's rota on and are required for any posi oning and naviga on: – Universal me – Coordinates of the pole (Polar Mo on). – Celes al pole offsets (Precession and Nuta on)
8/22/2012 h p://space-geodesy.nasa.gov 5 Pillar 3: Gravity Field, Mass Transport
8/22/2012 h p://space-geodesy.nasa.gov 6 Space Geodesy Applica ons
u Data from space geodesy measurements archive are u lized for direct science observa ons and geode c studies, e.g., plate mo on, gravity field, earthquake displacements, Earth orienta on, atmospheric angular momentum, etc. u Real- me data is used for natural hazards monitoring and early warning. u Data also contribute to the determina on of the Terrestrial Reference Frame (TRF), an accurate set of posi ons and veloci es. u Data used for Precise Orbit Determina on (POD). u Addi onal products include atmosphere measurements to aid in weather forecas ng, etc. u Measurements provide cri cal informa on for accurate deep space naviga on. u GSFC maintains the archival and distribu on of the worldwide space geode c data using the Crustal Dynamics Data Informa on System (CDDIS).
8/22/2012 h p://space-geodesy.nasa.gov 7 Space Geodesy Provides Posi oning, Naviga on, and Timing Reference Frames and Earth System Observa ons
http://www.nap.edu/catalog/12954.html
8/22/2012 h p://space-geodesy.nasa.gov 8 Space Geode c Systems
Very Long Baseline Interferometry (VLBI) Satellite Laser Ranging (SLR)
Doppler Orbitography and Radioposi oning Global Naviga on Satellite System (GNSS) Integrated by Satellite (DORIS)
8/22/2012 h p://space-geodesy.nasa.gov 9 Satellite Laser Ranging (SLR)
u Currently 23 opera onal sta ons worldwide acquiring data daily. u GSFC operates five SLR sta ons: – GGAO, Greenbelt, Maryland, – McDonald Observatory, Fort Davis, Texas (Univ. of Texas at Aus n), – Monument Peak, Mount Laguna, California, – Haleakala, Maui, Hawaii (Univ. of Hawaii, Ins tute for Astronomy), – Arequipa, Peru (Universidad Nacional de San Agus n (UNSA)). u GSFC supports three partner sta ons: – Tahi , French Polynesia (CNES, Univ. of French Polynesia), – Hartebeesthoek, South Africa (NRF, Hartebeesthoek Radio Observatory), – Yarragadee, Australia (Geoscience Australia). u GSFC provides the Central Bureau of the Interna onal Laser Ranging Service (ILRS) that coordinates the worldwide SLR network, observing, data processing and analysis. u GSFC maintains the archival and distribu on of the worldwide SLR data using the Crustal Dynamics Data Informa on System (CDDIS).
8/22/2012 h p://space-geodesy.nasa.gov 10 Very Long Baseline Interferometry (VLBI)
u 40 sta ons worldwide acquiring data, some daily. u GSFC operates 3 VLBI sta ons: – GGAO, Greenbelt, Maryland, – Wes ord, Massachuse s (MIT, Haystack Observatory), – Kokee Park, Hawaii. u GSFC provides support for 3 partner sta ons: – Svalbard, Norway (Norwegian Mapping Authority), – Fortaleza, Brazil (Mackenzie University), – Hobart, Australia (University of Tasmania). u GSFC provides oversight and training to VLBI partners. u GSFC provides the Coordina ng Center and an Analysis Center of the Interna onal VLBI Service for Geodesy and Astrometry (IVS) that schedule all interna onal geode c VLBI networks and observing, oversee data correla on and distribu on to the global archive, and perform VLBI data processing and analysis. u GSFC maintains the archival and distribu on of the worldwide VLBI geode c data using the Crustal Dynamics Data Informa on System (CDDIS).
8/22/2012 h p://space-geodesy.nasa.gov 11 Global Naviga on Satellite Systems (GNSS)
u This decade will see an explosion of new GNSS. u 440 GNSS tracking sta ons within the Interna onal GNSS Service (IGS) network. u 189 sta ons par cipa ng in the Real Time Pilot Project u Many more sta ons within other networks.
GPS Galileo GLONASS
8/22/2012 h p://space-geodesy.nasa.gov 12 GPS Laser Retroreflector Array Project
u Systema c co-loca on in space through the precision orbit determina on of GPS satellites via SLR will contribute significantly towards improving the accuracy and stability of the ITRF. u GPS will then provide a means to accurately and uniformly distribute this new accuracy to all systems u lizing GPS. u NASA-DoD partnership to support laser ranging of next genera on GPS satellites. – GSFC led instrument. – Partnering with the Naval Research Lab on Formula on, including the development and tes ng of a flight model. u First unit on GPS III SV9 scheduled for launch in 2019 to 2021 me frame. u Baseline delivery of at least 27 arrays.
8/22/2012 h p://space-geodesy.nasa.gov 13 Doppler Orbitography and Radioposi oning Integrated by Satellite (DORIS)
u GGAO DORIS beacon is part of a global network of ~57 sta ons since June 2000. u DORIS receivers are used on al meter (TOPEX, Jason1, Jason2, ENVISAT, Cryosat-2) and remote sensing (SPOT) satellites; Future Missions: Jason-3, SWOT & SENTINEL-3. u GSFC maintains the archival and distribu on of the worldwide DORIS geode c data using the Crustal Dynamics Data Informa on System (CDDIS).
8/22/2012 h p://space-geodesy.nasa.gov 14 Global Geode c Network
8/22/2012 h p://space-geodesy.nasa.gov 15 Global Geode c Observing System (GGOS) Services & Products
International Terrestrial , Reference Frame (ITRF) (Accurately positioned points with respect to the Earth's Center of Mass and the fixed background of Quasars)
International Earth Rotation and Reference Systems Service (IERS)
Precision GPS Orbits and Clocks, Earth, Rotation Parameters, Station Positions
Very Long Baseline Satellite Laser Global Navigation Doppler Orbit Determination Interferometry Ranging Satellite Systems and Radiopositioning Integrated on Satellite (IVS) (ILRS) (IGS) (IDS)
8/22/2012 h p://space-geodesy.nasa.gov 16 “Collapsing” Infrastructure
“Requirement for precise measurement and maintenance of the terrestrial reference frame. The geode c infrastructure needed to enhance or even to maintain the terrestrial reference frame is in danger of collapse (see Chapter 1). Improvements in accuracy and economic efficiency are needed. Inves ng resources to ensure the improvement and con nued opera on of the geode c infrastructure is a requirement of virtually all the missions proposed by every panel in this study. The terrestrial reference frame is realized through integra on of the high-precision networks of the Global Posi oning System (GPS), Very Long Baseline Interferometry (VLBI), and satellite laser ranging (SLR). It provides the founda on for virtually all space-based and ground-based observa ons in Earth science and studies of global change, including remote monitoring of sea level, sea-surface topography, plate mo ons, crustal deforma on, the geoid, and me-varying gravity from space. It is through this reference frame that all measurements can be interrelated for robust, long-term monitoring of global change. A precise reference frame is also essen al for interplanetary naviga on and diverse na onal strategic needs.” http://www.nap.edu/catalog/11820.html
8/22/2012 h p://space-geodesy.nasa.gov 17 Suppor ng Future Requirements
u Science Driver: – Most stringent requirement on the ITRF comes from sea level studies: • “accuracy of 1 mm, and stability at 0.1 mm/year” • This is a factor 10-20 beyond current capability. – About 30 modern integrated sta ons are required to meet these requirements. u NRC Recommenda ons: – Upgrade U.S. sta ons with modern SLR and VLBI, – Work with interna onal partners to deploy addi onal sta ons, – Establish and maintain a high precision real- me GNSS/GPS na onal network, – Make a long-term commitment to maintaining the ITRF, – Con nue to support the ac vi es of the GGOS. u NASA Response – Contribute to building a new global network of integrated geode c sta ons – Network should be there for the coming Decadal Survey missions. – NASA proposes to provide 6-10 of these sta ons if the next genera on technology can be demonstrated to func on as required. – Complete the next genera on SLR and VLBI developments.
8/22/2012 h p://space-geodesy.nasa.gov 18 The Space Geodesy Project
u New ini a ve started at the end of 2011 in response to the Earth Science Decadal and the Na onal Research Council study “Precise Geode c Infrastructure.” Part of the President’s Climate Ini a ve. u Goddard led in partnership with JPL and par cipa on from the Smithsonian Astrophysical Observatory and the University of Maryland. u Goals: – Establish and operate a prototype next genera on space geode c sta on with integrated next genera on SLR, VLBI, GNSS (and DORIS) systems, along with a system that provides for accurate vector es between them. – Develop a Project Implementa on Plan for the construc on, deployment and opera on of a NASA network of similar next genera on sta ons that will become the core of a larger global network of modern space geode c sta ons.
VLBI NGSLR GNSS Vector Tie
8/22/2012 h p://space-geodesy.nasa.gov 19 Prototype Geode c Sta on at GGAO
u Goddard Geophysical and Astronomical Observatory (GGAO) is located 5 km from Goddard Space Flight Center in the middle of the Beltsville Agricultural Research Center. GGAO is one of the few sites in the world to have all four geode c techniques co-located at a single loca on.
VLBI2010 MV-3 VLBI GGAO
Legacy GNSS 48”
Reference mark New GNSS GSFC MOBLAS-7
NGSLR DORIS REGINA GNSS
8/22/2012 h p://space-geodesy.nasa.gov 20 Prototype Sta on Status Summary
u Prototype sta on is currently on-schedule for an August 2013 comple on. u NGSLR successfully tracked 20 of out of the 33 current ILRS satellites, including daylight ranging to GNSS (GLONASS-109 & 115). u NGSLR met a major milestone by comple ng the development of a new high-power op cal bench. Installa on at the prototype sta on is underway. u Prototype VLBI2010 antenna performed first end-to-end geode c session on May 16, 2012. u New GNSS receivers con nue to operate well over the past 6 months.
8/22/2012 h p://space-geodesy.nasa.gov 21 Future Network Development Status
u Completed site assessments of Kokee Park, Haleakala, and Greenbelt. Monument Peak assessment nearly complete. Assessment of other US sites underway. u Implementa on plan under development for an early delivery by the end of the year. u On-going discussions with exis ng and poten al interna onal partners: – Brazil, Ins tuto Nacional de Pesquisas Espaciais(INPE) – Colombia, Ins tuto Geografico Agus n Codazzi (IGAC) – Finland, Finnish Geode c Ins tute (FGI) – France, Centre Na onal d'Etudes Spa ales (CNES) – Korea, Korea Astronomy and Space Science Ins tute (KASI) – Norway, Norwegian Mapping Authority (NMA) – Peru, Pedro Paulet Ins tute of Astronomy and Aeronau cs – Taiwan, Ins tute of Earth Sciences Academia Sinica
8/22/2012 h p://space-geodesy.nasa.gov 22 Training the next genera on
Six interns worked with the SGP team on tasks ranging SGP hosted a summer intern tour of the Goddard prototype from the NGSLR telescope mount, to VLBI radio sta on on July 3 for all Goddard summer interns. interference, to analysis of geode c data.
The interns also performed surveying The summer interns presented their work at tasks at the prototype sta on. the Intern Poster Session on July 25, 2012.
8/22/2012 h p://space-geodesy.nasa.gov 23