Sander Geophysics - Progress Report

Summer 2004

Sander Geophysics is Growing Again

To keep up with the high demand for quality airborne surveys, Sander Geophysics has hired additional staff and purchased new aircraft. We now employ about 100 people, and own and operate ten survey aircraft to serve our worldwide clients. Our geophysical survey business continues to operate near full capacity, and we are currently conducting airborne gravity, gamma ray spectrometer, magnetic gradiometry, and high resolution magnetic surveys in the Americas, Africa and the Middle East.

New Aircraft

In the last year, we have acquired three new aircraft: a Britten-Norman Islander, a Cessna Grand Caravan and a Eurocopter AS350-B3 helicopter. We now own and operate nine airplanes, including six Cessna Grand Caravans, as well as the helicopter. All ten of our aircraft are extensively modified for geophysical surveying.

Airborne Gravity with AIRGrav

Our biggest research and development effort over the last ten years has been to design and manufacture the AIRGrav airborne gravity system. It is the first instrument built specifically for airborne gravimetry, and it has proven to be the best instrument for the job. Since the introduction of AIRGrav five years ago, we have managed to steadily improve our gravity survey instrumentation and GPS-based calculations of aircraft accelerations. We are now able to measure gravity anomalies of 2 km diameter with an accuracy of 0.3 mGal RMS, using an airplane. The resolution of an AIRGrav survey depends on the speed of the aircraft, which is why SGL recently purchased a helicopter. The helicopter is capable of flying at half the speed of an airplane, to achieve twice the AIRGrav data resolution. A helicopter AIRGrav survey can define a small 1 mGal anomaly of 1 km diameter. This is exceptional accuracy and resolution for petroleum surveys, and further enhances the value of our airborne gravity surveys for mining exploration. While it is more expensive to survey with a helicopter than an airplane, the relatively small difference in price is often easily justified by the increase in data resolution. High resolution magnetics can easily be combined with an airplane or helicopter AIRGrav survey. The combination of these two potential field methods has proven very powerful for many types of resource exploration. SGL's AIRGrav airborne gravity surveys have steadily gained acceptance. In 2002, we surveyed 30,000 line kilometers of airborne gravity surveys; in 2003 we flew 70,000 line kilometers; and in the first half of 2004 we have already flown or booked contracts for 150,000 line km.

Worldwide Services

Sander Geophysics offers airplane and helicopter geophysical surveys anywhere in the world. If you would like to find out more about our AIRGrav system or any of SGL's other airborne geophysical survey methods, please visit or contact us directly.