Position, Navigation, and Timing Technologies in the 21st Century. Группа авторов

Anthorn eLoran transmitter (left)...Figure 41.18 ASFs of the UK Anthorn eLoran transmitter. The top‐left figure ...Figure 41.19 Temporal variation regions for the United States expressed in n...Figure 41.20 Detail of the I‐495 South track. The red lines depict the E‐fie...Figure 41.21 Land‐mobile ASFs measured along the 495‐South in Massachusetts,...Figure 41.22 Positioning performance during Tampa Bay Harbor Entrance and Ap...Figure 41.23 Comparison of CCIR noise predictions for North America and West...Figure 41.24 Example of interference in automotive Loran applications. Top: ...Figure 41.25 Cross‐rate between the European Loran chains GRI 6731 and GRI 9...Figure 41.26 The sky‐wave of the cross‐rating pulse (red) hits the tracking ...Figure 41.27 Legacy Loran‐C receivers: SI‐TEX XJ‐1 (left) and Koden LR‐770 (...Figure 41.28 Legacy line‐of‐position (LOP) chart for the US 9960 chain (left...Figure 41.29 Representative rack‐mount eLoran receivers.Figure 41.30 eLoran receiver design – signal reception and conditioning.Figure 41.31 A steep, narrow bandpass filter causes severe attenuation at th...Figure 41.32 Non‐causal “filt‐filt” filtering does preserve the phase and mo...Figure 41.33 Dual‐band (eLoran and GPS) E‐field antenna (left) and the inter...Figure 41.34 Equivalent receiver‐noise field strength.Figure 41.35 E‐field antenna followed by a charge‐amplifier. C_a depicts the ...Figure 41.36 Ferrite‐loaded loop (left) and its equivalent circuit (right)....Figure 41.37 H‐field antenna in (left) resonance configuration and (right) w...Figure 41.38 Influence of rod length and rod diameter on noise performance (...Figure 41.39 Angular‐dependent TOA measurement error due to E‐field suscepti...Figure 41.40 H‐field antenna tuning errors measured during a data collection...Figure 41.41 Various sources of cross‐coupling or “cross‐talk” in an active ...Figure 41.42 eLoran research measurement setup installed on a boat. The H‐fi...Figure 41.43 Uncorrected H‐field antenna response (blue=loop 1, red=loop 2)....Figure 41.44 Antenna response after cross‐talk correction (blue depicts loop...Figure 41.45 eLoran receiver design – signal tracking, correction, and posit...Figure 41.46 eLoran positioning performance measured in 2014 on board the P...Figure 41.47 eLoran providing timing inside NYSE, accurate within 16.1 ns re...Figure 41.48 Transmitted alternative waveforms (Schue et al. [104]).Figure 41.49 Alternative waveforms in the time domain (left) and frequency d...

      8 Chapter 42Figure 42.1 Chain Home radio tower (public domain).Figure 42.2 Maritime radar system display. The shape of the land masses near...Figure 42.3 The first SAR image, developed by the University of Michigan in ...Figure 42.4 SAR imagery of western Pennsylvania terrain, generated in the 19...Figure 42.5 Modern SAR image, generated in real‐time during flight by a mini...Figure 42.6 Overview of the typical stages in a radar system.Figure 42.7 Polar format mismatch between collected data and the reconstruct...Figure 42.8 Example transmitted OFDM symbol with random modulation.Figure 42.9 Example transmitted OFDM symbol with preset modulation on the fi...Figure 42.10 Overview of the navigation system implemented.Figure 42.11 Overview of radar signal processing method.Figure 42.12 Illustration of radar slow time versus fast time. The radar sys...Figure 42.13 Matched filter output of an OFDM pulse reflecting off a perfect...Figure 42.14 Matched filter output of an OFDM pulse reflecting off three ref...Figure 42.15 MF SNR histogram for target and no target scenarios. The true M...Figure 42.16 Stochastic exploration of large SAR data sets.Figure 42.17 Block diagram of experimental UWB‐OFDM radar system.Figure 42.18 SAR image captured with experimental system via backprojection....Figure 42.19 BER of experimental system transmitting at a data rate of 57 Mb...Figure 42.20 SAR phase history magnitude (observing a single stationary corn...Figure 42.21 Fast‐time collection after pulse compression (observing a singl...Figure 42.22 Phase history after pulse compression (observing a single stati...Figure 42.23 Phase history after pulse compression (observing a single corne...Figure 42.24 Single track extracted range history for data set in Figure 42....Figure 42.25 Phase history after pulse compression for moving radar in hallw...Figure 42.26 Phase history after pulse compression. Short sample taken from ...Figure 42.27 SAR data set computed navigation solutions, shown with and with...

      9 Chapter 43aFigure 43.1 The 1419 operational satellites in orbit in 2016 (Reid [4]).Figure 43.2 Radiation dosage in silicon over a five‐year mission as a functi...Figure 43.3 The Transit “bird cage” constellation. This typically consisted ...Figure 43.4 The 66 satellite Iridium constellation in low Earth orbit (LEO) ...Figure 43.5 The OneWeb constellation of 648 satellites (Reid [4]).Figure 43.6 Slant range to the satellite.Figure 43.7 Slant range and spreading loss as a function of orbital altitude...Figure 43.8 Comparison of signal‐to‐noise ratio for Satelles Satellite Time ...Figure 43.9 Satellite mean motion and orbital period as a function of altitu...Figure 43.10 Comparison of medium and low Earth orbit (LEO) satellite distan...Figure 43.11 Satellite footprint radius as a function of orbital altitude an...Figure 43.12 Number of satellites in view as a function of latitude for the ...Figure 43.13 Iridium‐based STL test locations. These are indoor and deep att...Figure 43.14 Iridium‐based STL timekeeping results based on data from a 30‐d...Figure 43.15 Iridium‐based STL geolocation performance. This shows the conve...Figure 43.16 Roadmap to an LEO navigation system. The user position error is...Figure 43.17 Comparison of 98th percentile geometric dilution of precision (...Figure 43.18 Comparison of user HDOP (95th percentile) as a function of lati...Figure 43.19 Comparison of user vertical dilution of precision (VDOP) (95th ...Figure 43.20 Radiation dosage in silicon over a five‐year mission in LEO and...

      10 Chapter 43bFigure 43.21 Existing and future LEO satellite constellations (Kassas et al....Figure 43.22 Residual errors showing the effect of (i) satellite position an...Figure 43.23 SGP4 (a) position and (b) velocity errors. (Kassas et al. [6])....Figure 43.24 Time evolution of 1 − σ bounds of (a) clock bias and...Figure 43.25 (a) Skyplot showing the trajectory of an Orbcomm LEO satellite ...Figure 43.26 Simulated delays in meters due to ionosphere and troposphere pr...Figure 43.27 Ionospheric delay rates (expressed in m/s) for seven Orbcomm sa...Figure 43.28 Orbcomm LEO satellite constellation (Morales et al. [4]).Figure 43.29 Navigation receiver: (a) Each channel is first extracted then f...Figure 43.30 Snapshot of the Orbcomm spectrum (Kassas et al. [6]).Figure 43.31 Outputs of Orbcomm receiver: (a) estimated Doppler, (b) carrier...Figure 43.32 Visualization of proposed LEO Starlink satellites (Ardito et al...Figure 43.33 Base/rover CD–LEO framework. The base, which can be a stationar...Figure 43.34 LEO‐aided INS STAN framework (Morales et al. [4]).Figure 43.35 Logarithm of the PDOP as a function of time at two positions on...Figure 43.36 Heat map of log₁₀[PDOP] for Orbcomm constellation and an 8 min ...Figure 43.37 Heat map of log₁₀[PDOP] for the Orbcomm constellation and an 8 ...Figure 43.38 Snapshot of the Starlink LEO constellation (Kassas et al. [6])....Figure 43.39 Heat map showing a snapshot of the number of visible Starlink L...Figure 43.40 Heat map showing PDOP for the Starlink LEO constellation above ...Figure 43.41 Heat map showing log₁₀[DPDOP] for the Starlink LEO constellatio...Figure 43.42 UAV simulation environment with the Globalstar, Orbcomm, and Ir...Figure 43.43 UAV simulation results with the Globalstar, Orbcomm, and Iridiu...Figure 43.44 UAV simulation environment with the Starlink LEO constellation....Figure 43.45 UAV simulation results with the Starlink LEO constellation. (a)...Figure 43.46 Experimental results showing (a) the expected and measured Dopp...Figure 43.47 Base/rover experimental setup of the CD–LEO framework (Khalife ...Figure 43.48 (a) Sky plot showing the geometry of the two Orbcomm satellites...Figure 43.49 Trajectory of the two Orbcomm satellites during the experiment,...Figure 43.50 Hardware and software setup for the ground vehicle experiment (A...Figure 43.51 (a) Skyplot of the Orbcomm satellite trajectories. (b) Doppler ...Figure 43.52 Results of the ground vehicle experiment. (a) Orbcomm satellite...Figure 43.53 Hardware and software setup for the UAV experiment (Morales et ...Figure 43.54 (a) Skyplot of the Orbcomm satellite trajectories. (b) Doppler ...Figure 43.55 Results of the UAV experiment. (a) Orbcomm satellite trajectori...

      11 Chapter 44Figure 44.1 Simplified schematic of a strapdown inertial navigation system (...Figure 44.2 A simple navigation problem to illustrate the effects of errors ...Figure 44.3 Effect of initial condition errors on the navigation error versu...Figure 44.4 Outputs of an ideal sensor and a practical sensor are plotted ve...Figure 44.5 Effect of bias and noise for accelerometers and gyroscopes on th...Figure 44.6 Rotations around the north or east axes, or leveling errors, cau...Figure 44.7 Family tree for accelerometer mechanizations. All types require ...Figure 44.8 As an atom absorbs a photon, the momentum of the photon slows th...Figure 44.9 Three pairs of counterpropagating optical beams combined with a ...Figure 44.10 Schematic diagram