LORENTZ FORCE VELOCIMETER

One or more Lorentz force velocimeters are provided. Each Lorentz force velocimeter is configured to sense electric field strength. Each Lorentz force velocimeter measures electric field strength due to a magnetic Lorentz force. Lorentz electric field is derived from alternating measurements of the ambient electric field and a sum of the ambient electric field and the Lorentz electric field. To accomplish this, optionally, a magnetic shield shutter alternatively (a) encloses, at least partially, the electric field sensor and diminishes the Earth's magnetic field strength at the electric field sensor and (b) does not enclose the electric field sensor and does not diminish the Earth's magnetic field strength at the electric field sensor.