Filling the need for a book that conveys the current technology as well as the underlying history and physical background, this book tells physicists and engineers how to measure time to the precision required for modern-day use. The authors draw on their longstanding research experience with timekeeping and high-precision measurement to cover the use of satellites in measuring earth movement variation and the influence of the moon, while also dwelling on such topics as timekeeping aboard satellites and time transfer.
Indispensable for high-precision measurements of processes in astrophysics, and relevant for measurement, navigation and communication, this monograph can be equally used as a course book or as accompanying work at advanced undergraduate or graduate level.
Author(s): Dennis D. McCarthy, P. Kenneth Seidelmann
Publisher: Wiley-VCH
Year: 2009
Language: English
Pages: 375
TIME – From Earth Rotation to Atomic Physics......Page 5
Contents......Page 9
Preface......Page 17
Acronyms......Page 19
1.2 Characterizing Time......Page 25
1.3 Calendars......Page 26
1.4 Astronomical Observations......Page 27
1.5 Timekeeping......Page 28
1.6 Time Epochs......Page 29
1.7 Time Transfer......Page 30
1.9 Beginning the Twentieth Century......Page 31
References......Page 32
2.2 Mean Solar Time......Page 33
2.4 Sidereal Time......Page 35
2.5 Washington Conference of 1884......Page 36
2.6 Newcomb’s Theory of the Sun......Page 37
2.7 Universal Time......Page 38
2.8 Coordinated Universal Time (UTC)......Page 40
2.9 Greenwich Mean Time (GMT)......Page 41
2.10 Tropical Year......Page 42
2.12 Reference System......Page 43
2.14 Daylight Saving Time......Page 44
References......Page 46
3.2 Before Kepler and Newton......Page 47
3.3 Kepler and Newton......Page 50
3.4 Tables, General Theories, and Ephemerides......Page 51
3.5 Lunar Theories......Page 53
3.6 The Advent of Computers......Page 56
3.8 Observational Data......Page 57
3.9 Dynamical Reference Frame......Page 58
3.10 Time Arguments......Page 59
3.12 Artificial Satellite Theories......Page 60
References......Page 61
4.1 Pre 19th Century......Page 65
4.2 Secular Variation......Page 66
4.3 Irregular Variations in the Earth’s Rotation......Page 68
4.4 Early Explanations for the Variable Rotation......Page 76
4.5 Current Understanding of the Earth’s Variable Rotation......Page 77
4.6 Consequences......Page 79
References......Page 81
5.1 Earth Orientation......Page 85
5.1.1 Precession/Nutation......Page 89
5.1.2 Polar Motion......Page 90
5.1.3 UT1......Page 92
5.2.1 Precession Nutation......Page 93
5.2.2.2 Decadal Variations......Page 94
5.2.2.4 Other Variations......Page 95
5.3 Transforming Between Reference Frames......Page 96
5.4 Determination of Earth Orientation......Page 99
5.5 Earth Orientation Data......Page 100
References......Page 101
6.1 Need for a Uniform Time Scale......Page 103
6.2 Danjon Proposal......Page 104
6.3 Clemence’s Proposal......Page 105
6.4 Adoption and Definition......Page 107
6.5 Observational Determination......Page 108
6.6 The Ephemeris Second and Atomic Time......Page 110
6.7 Historical DT......Page 111
6.8 Problems with Ephemeris Time......Page 114
6.9 Relativity......Page 115
6.10 Dynamical Time Scales......Page 116
References......Page 117
7.2 Special Relativity......Page 119
7.3 Lorentz Transformations......Page 121
7.4 Coordinate and Proper Time......Page 122
7.5 Minkowski Diagrams......Page 123
7.6 Time in Special Relativity......Page 126
7.7.1 Metrics in General Relativity......Page 127
7.7.2 The Equivalence Principle......Page 128
7.8 IAU Resolutions......Page 129
7.10 Relativistic Effects in Time Transfer......Page 135
References......Page 136
8.1 Replacing Ephemeris Time......Page 137
8.2 Terrestrial Dynamical Time (TDT) and Barycentric Dynamical Time (TDB)......Page 138
8.3 Problems with TDT and TDB......Page 140
8.4 New Reference System......Page 141
8.5 New Time Scales......Page 142
8.5.2 Terrestrial Time......Page 143
8.5.4 Barycentric Coordinate Time......Page 144
8.5.6 TDB Redefined......Page 146
8.6 DT and Ephemeris Time Revised......Page 148
8.7 Relationships Among Coordinate Time Scales......Page 149
References......Page 150
9.2 Keeping Time in Antiquity......Page 153
9.2.1 Clepsydrae and Water ‘Clocks’......Page 154
9.2.2 Other Timekeeping Devices......Page 155
9.3 The First Mechanical Clocks......Page 156
9.4.1 Galileo......Page 157
9.4.2 Huygens......Page 158
9.4.3 Pendulum Clock Developments......Page 160
9.4.4 Chronometers......Page 162
9.5 Quartz Crystal Clocks......Page 163
9.6.1 Quality (Q) Factor......Page 166
9.6.3 Accuracy......Page 167
9.6.4 Stability......Page 168
References......Page 173
10.1 Beyond Quartz-Crystal Oscillators......Page 175
10.2 Physics of Atomic Clocks......Page 176
10.3 General Structure of Atomic Clocks......Page 178
10.4 Development of Atomic Clocks......Page 181
10.4.1 Cesium......Page 182
10.4.1.1 Calibration of the Cesium Frequency......Page 184
10.4.1.2 Cesium Beam Tubes......Page 186
10.4.1.3 Cesium Fountains......Page 190
10.4.2 Hydrogen......Page 193
10.4.2.1 Active Hydrogen Maser......Page 194
10.4.2.2 Passive Hydrogen Masers......Page 195
10.4.3.1 Rubidium Cells......Page 196
10.4.3.3 Double-bulb Rubidium Maser......Page 197
10.5 Stored Ion Clocks......Page 198
10.5.1 Mercury......Page 199
10.6 Characterizing Atomic Clocks......Page 201
References......Page 202
11.1 Optical Transition Frequencies......Page 205
11.2 Optical Ion Clocks......Page 207
11.4 Quantum Logic Clock......Page 208
References......Page 210
12.1 The Historical Second......Page 213
12.2 The Ephemeris Second......Page 215
12.3 The SI Second......Page 216
12.4 Adopting the SI Second......Page 219
References......Page 221
13.1 Constructing an Atomic Time Scale......Page 223
13.2 History of TAI......Page 225
13.3 Formation of TAI......Page 231
13.3.1 EAL......Page 232
13.3.2 Steering EAL with Primary Frequency Standards......Page 239
13.5 Distribution of TAI......Page 240
13.6 Relationship of TAI to Terrestrial Time......Page 242
References......Page 246
14.1 Universal Time Before 1972......Page 247
14.2 Coordinated Universal Time After 1972......Page 251
14.3 Leap Seconds......Page 253
14.5 UTC Worldwide......Page 255
14.7 The Future of UTC – Leap Seconds or Not?......Page 256
References......Page 257
15.1 The Solar System......Page 259
15.3 Pursuit of Accuracy......Page 260
15.4.1 Eclipses, Occultations, Transits......Page 261
15.4.3 Moonrises and Moonsets......Page 263
15.5 Time and Distance......Page 264
15.5.2 Radar Ranging......Page 265
15.5.4 Navigation Systems......Page 266
15.7 Proper Times at Planets......Page 270
15.8 Pulsars – An Independent Source of Time?......Page 271
References......Page 272
16.1 Historical Transfer Techniques......Page 273
16.2.1 Propagation Effects......Page 274
16.2.3 Relativistic Effects......Page 275
16.2.3.2 Nonrotating Local Inertial Reference Frame......Page 276
16.2.3.4 Electromagnetic Signals Transfer in a Nonrotating Local Inertial Reference Frame......Page 277
16.3.4 Microwave Links......Page 278
16.3.7 High-Frequency Radio Signals......Page 279
16.3.8 Low-Frequency Broadcast Radio Signals......Page 280
16.3.9 Low-Frequency Navigation Signals......Page 281
16.3.10.2 GLONASS......Page 282
16.3.12 Two-Way Satellite Time and Frequency Transfer......Page 283
References......Page 284
17.1 Terrestrial to Celestial Reference Systems......Page 287
17.2 Determination of Earth Orientation Parameters......Page 288
17.2.1 Very Long Baseline Interferometry (VLBI)......Page 289
17.2.2 Global Positioning System (GPS)......Page 294
17.2.3 Satellite Laser Ranging (SLR)......Page 296
17.2.5 Geophysical Modeling......Page 300
17.3 Earth Orientation Data......Page 303
References......Page 304
18.2 Treaty of the Meter......Page 305
18.2.2 International Committee on Weights and Measures (CIPM)......Page 306
18.3 Scientific Unions......Page 307
18.3.1 International Astronomical Union (IAU)......Page 308
18.3.2 International Union of Geodesy and Geophysics (IUGG)......Page 309
18.3.3 International Telecommunications Union (ITU)......Page 310
18.4 Service Organizations......Page 312
18.4.1 International Earth Rotation and Reference Systems Service (IERS)......Page 314
18.4.3 International Laser Ranging Service (ILRS)......Page 317
18.4.4 International GNSS (Global Navigational Satellite Service) Service (IGS)......Page 318
18.4.5 International DORIS Service (IDS)......Page 319
References......Page 320
19.2 Positioning and Navigation Services......Page 321
19.3 Communications......Page 322
19.4 Power Grid......Page 324
19.8 Summary......Page 325
Reference......Page 328
20.1 Future Needs for Time......Page 329
20.2 Modeling the Earth’s Rotation......Page 330
20.4 Future Time Scales......Page 331
20.5 Future Time Distribution......Page 332
Glossary......Page 335
Index......Page 361
