Single-frequency Global positioning system 3 Continuous wave lasers 2 Continuous-wave lasers 2 Machine learning 2 Machine-learning 2 Neural networks 2 Tunables 2 machine learning 2 Acoustic transmission 1 Acoustic transmission coefficient 1 Acoustic wave propagation 1 Active landslides 1 Adaptive control systems 1 Antenna calibration 1 BP neural network 1 Back-propagation neural networks 1 Backpropagation 1 CYGNSS 1 Calibration 1 Controllers 1 Cost effective 1 Cost effectiveness 1 Costs 1 Crystal structure 1 Crystals 1 Delay models 1 Diffraction gratings 1 Early warning 1 Eastern Alps 1