US 8,787,619 B2 · Temporal thermal imaging method for detecting subsurface objects and voids

Abstract

A temporal thermal survey method to locate at a given area whether or not there is a subsurface object or void site. The method uses thermal inertia change detection. It locates temporal heat flows from naturally heated subsurface objects or faulty structures such as corrosion damage. The added value over earlier methods is the use of empirical methods to specify the optimum times for locating subsurface objects or voids amidst clutter and undisturbed host materials. Thermal inertia, or thermal effusivity, is the bulk material resistance to temperature change. Surface temperature highs and lows are shifted in time at the subsurface object or void site relative to the undisturbed host material sites. The Dual-band Infra-Red Effusivity Computed Tomography (DIRECT) method verifies the optimum two times to detect thermal inertia outliers at the subsurface object or void border with undisturbed host materials.

Claims26

Dependent claims

A temporal thermal method for detecting thermal inertia differences comprising:

using an empirical method to determine a first imaging time and a second imaging time;
creating a first temperature map from data obtained by imaging at least one IR wavelength band at the first imaging time at a first location and a second location;
creating a second temperature map from data obtained by imaging at least one IR wavelength band at the second imaging time at the first location and the second location;
and
using a computer to determine the existence of a thermal inertia difference between the first location and the second location using the first and second temperature maps, wherein the first imaging time occurs before the first location reaches its daily low thermal response or annual low thermal response, and wherein the second imaging time occurs before the first location reaches its daily high thermal response or annual high thermal response;
wherein the temperature difference between the first location and the second location is greater than a surface emissivity noise of the first and second locations, whereby the first imaging time and the second imaging time occur when the thermal response between the first and second locations is sufficient to detect an artifact at one of the locations.

3 more elements

Dependencies are inferred from the claim text.

Temporal thermal imaging method for detecting subsurface objects and voids

Life of this patent

Temporal thermal imaging method for detecting subsurface objects and voids

Life of this patent

Abstract

Claims26