Geo-Temp’s novel DIRECT^® (Dual Infra-Red Effusivity Computed Tomography) Service heat flow surveys identify buried tunnel voids (air gaps). Computer algorithms mitigate surface-object clutter. Field tests optimize heat-flow survey dates and times. Attention to the weather provides successful results. Heat flow surveys identified voids 1 to 3 m high, beneath 20 to 60 m of disturbed earth. Heat flow calibrations were taken at a surrogate site using highly accurate soil temperature-probes. Buried tunnel empty space areas have outlier heat flows compared to undisturbed areas.

Below are examples of successful heat flow surveys that identified the sites of buried objects.

• Dual Band Infrared Survey Method Mapped Buried Mines (Yuma, AZ);
• Archaeological Mission: Mapping “Lost Adobe” Siltstone Foundation (Santa Cruz, CA);
• Thermal Inertia Method Characterizes Retaining Wall Cracks (Jerusalem, Israel);
• Thermal Inertia Method Mapped Buried Drain Under Rock Platform (Jerusalem, Israel);
• Dual Band IR Survey Mission: Mapping A 6-60 Meter Deep Aquifer (Long Valley, CA);
• Mobile Van Mission: Mapping Delamination Cracks (Grass Valley Creek Bridges, CA);
• DIRECT^® Surveys View Deep Crossed Pipe Enhanced Heat Flows (Dugway, UT); and
• DIRECT^® Survey Mission: Locating A Smuggler’s Border Stash (Brownsville, TX).