A system and method for airborne geophysical exploration over the ground are disclosed. In one embodiment of the system, two towing bodies are towed behind an aircraft in flight in a vertically spaced-apart relation above a ground station. Respective magnetometer measurement instruments are located within each of the towing bodies and the ground station. Each magnetometer measurement instrument collects total field magnitude data to contribute to the magnetic vertical gradient data relative to magnetic crustal anomalies of geological origin and variations in an ambient magnetic field above the surface area of the survey. Each magnetometer measurement instrument also collects location, time, and inertial data substantially simultaneously with the total field magnitude data to provide position-correlated measurements thereof.