| |
1964-1969 |
1970-1974 |
1975-1979 |
1980-1984 |
1985-1989 |
1990-1994 |
1995-1998 |
| EARTH DYNAMICS |
Station Positions to 20m |
Station positions determined globally to 5 meters |
First SLR measurement of tectonic plate motion with SAFE |
First strong correlation between contemporary tectonic motion and geologic models |
SLR/VLBI establish first cm accuracy terrestrial reference frame |
CDP measures contemporary plate motion to mm/yr resolution |
SLR measures tidally induced motion of the geocenter |
| SLR provides scale to geodetic satellite measurements |
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SLR defines terrestrial scale (GM) and frame origin (c/m) to few mm. |
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| -- |
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SLR observed bias in paleomagnetic time scale confirmed by geochronologists |
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| GRAVITY FIELD |
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SLR data improves long wavelength gravity field model |
LLR improves Earth's GM |
SLR improves precision of GM by a factor of 10 |
Earth and ocean tidal signals detected |
Zonal time variations correlate with global atmos. pressure and ocean mass
redistribution |
SLR time varying gravity field constrains global atmospheric and ocean circulation and
tidal models |
| -- |
SLR combined with surface gravity improves intermediate wavelengths |
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Dynamic response to internal convection observed |
Realistic ocean tide model developed |
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Combined SLR/altimetry data improves marine geiod definition |
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Effects of Ice sheet change and post-glacial rebound observed |
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| EARTH ROTATION |
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LLR dominant contributor to UT1 |
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BIH relies on SLR, LLR, and VLBI for monitoring Earth orientation and pole |
Through strong correlation with SLR polar motion, the role of atmospheric winds and
EOP is understood |
Correction to precesion and nutation determined from LLR |
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| -- |
One component of polar motion to submeter accuracy with SLR |
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Global atmospheric angular momentum correlated with LLR LOD |
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| OCEAN, ICE, AND LAND TOPOGRAPHY |
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GEOS-3 and Seasat ocean surface altimetry defined by SLR orbit |
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TOPEX with SLR and RF tracking gives centimeter ocean topography and wave height, and
shows 3mm/yr. rates in global mean sea level |
First comprehensive ice topography mapping by ERS-1/2 altimeters tracked by SLR |
| -- |
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Land topography mapping mission by altimetry with SLR tracking under development |
| LUNAR SCIENCE, RELATIVITY, AND ORBIT |
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Seleocentric Reference System Established |
LLR tests Strong Equivalence Principle |
Lunar ephemeris accurate to 10 cm. |
Geodetic precession agrees with relativity to 2% |
Lunar tidal acceleration to 0.5 arcsec/century |
LLR constrains rate of change of gravitational constant G |
| -- |
Lunar orbit determined to 1m |
First measurement of lunar tidal deceleration |
Improved dynamic equinox and obliquity of ecliptic |
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Lunar ephemeris accurate to 3 cm. |
Nature of lunar interior investigated with LLR |
| -- |
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Lunar free libration and dissipation discovered |
Lunar elasticity detected |
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Ephemeris orientation determined to milliarcsec |
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| PROGRAMS |
National Geodetic Satellite Program |
San Andeas Fault Experiment |
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NASA Crustal Dynamics Program |
NASA DOSE Program |
DOSE-2 Program |
| US and France organize early SLR tracking programs |
ISAGEX |
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WEGENER/MEDLAS Program |
Expanded WEGENER Program |
| -- |
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APSG Program |
| TECHNOLOGY |
First SLR tracking from GSFC to 3 m precision |
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NASA and University of Texas develop first highly mobile SLR systems |
Germans and Dutch build highly mobile systems for WEGENER |
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System automation reduces personnel costs at field stations |
Development of fully automated SLR 2000 underway |
| First daylight ranging |
Introduction of signal processing gives network decimeter accuracy |
Introduction of cavity dump laser gives subdecimeter ranging accuracy |
Introduction of mode-locked lasers gives ranging accuracy of a few cm |
Installation of Microchannel plate tube detectors and dual-channel discriminators
gives routine sub-cm ranging |
Two color ranging to satellites and the moon show effects of atmospheric refraction be
measured |
Time transferred globally by SLR to 50 psec. |
| First LLR station established at McDonald Observatory |
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Laser timing experiments with satellites demonstrate sub-nsec time transfer |
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| SATELLITE LAUNCHES |
First SLR Ranging to BE-B |
Peole (Fr.) |
LAGEOS (US) |
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AJISAI (Jap.) |
LAGEOS-2 (It./US) |
ERS-2 (ESA) |
| -- |
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STARLETTE (Fr.) |
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ETALON 1/2 (Rus.) |
STELLA (Fr.) |
GFZ-1 (Ger.) |
| First Lunar Ranging/Apollo 11 |
Apollo 14/15 |
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GPS 35/36 (US) |
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| -- |
Lunakod 1/2 |
GEOS-3 (US) |
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GLONASS (Rus) |
SUNSAT (SA) |
| BE-B/C (US) |
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SEASAT (US) |
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METEOR 2/3 (Rus) |
ADEOS (Jap.) |
| GEOS-1/2 (US) |
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TOPEX (US/Fr) |
Champ (Ger.) |
| D1-C/D (Fr.) |
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ERS-1 (ESA) |
WPLTN-1 (Rus) |
| -- |
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MIR/HMS (Rus/US) |
| -- |
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TOPEX-2 (Fr./US) |
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TiPS (US DoD) |
| -- |
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GFO-1 (US DoD) |
About the ILRS 
