This self-contained book provides a basic foundation for students, practitioners, and researchers interested in some of the diverse new areas of multiscale (geo)potential theory. New mathematical methods are developed enabling the gravitational potential of a planetary body to be modeled and analyzed using a continuous flow of observations from land or satellite devices. Harmonic wavelet methods are introduced, as well as fast computational schemes and various numerical test examples.Topic and key features: - Comprehensive coverage of topics which, thus far, are only scattered in journal articles and conference proceedings- Important applications and developments for future satellite scenarios; new modelling techniques involving low-orbiting satellites- Multiscale approaches for numerous geoscientific problems, including geoidal determination, magnetic field reconstruction, deformation analysis, and density variation modelling- Exercises at the end of each chapter and an appendix with hints to their solutions