Using infrared satellite images taken from space, scientists at the University of Alabama at Birmingham have uncovered seventeen "lost" Egyptian pyramids and an extensive, ancient city buried out of sight for thousands of years. The infrared images, captured by National Aeronautics and Space Administration (NASA) satellites orbiting 430 miles above Earth, revealed 3,000 ancient settlements and 1,000 tombs at Tanis, Egypt - the city made famous as the fictional home of the Ark in Raiders of the Lost Ark.
Infrared satellite imaging works by capturing sensory data about the temperature of infrared radiation (or heat) emitted from the Earth. Special cameras detect differences in temperature and then assign false colors to them in order to create a picture that our eyes can interpret. American National Standards Institute (ANSI) member and audited designator ASTM International has published several standards that support thermal infrared imaging, including the following:
ASTM E1213-97(2009), Standard Test Method for Minimum Resolvable Temperature Difference for Thermal Imaging Systems, relates to a thermal imaging system's effectiveness for discerning details in a scene. The standard is used to determine the minimum resolvable temperature difference capability of a thermal imaging system, thereby helping to estimate resolution capability.
ASTM E1311-89(2010), Standard Test Method for Minimum Detectable Temperature Difference for Thermal Imaging Systems, covers the determination of the minimum detectable temperature difference capability of a thermal imaging system, and gives a measure of a thermal imaging system's effectiveness for detecting a small spot within a large background.
When it comes to archaeological and other environmental studies, there are a number of methods that scientists can use to "look" beneath Earth's surface.
Gravity measurements, for example, can indicate variations in the earth's gravitational field caused by lateral differences in the density of the subsurface soil or the presence of man-made structures or natural voids. Detailed gravity surveys can be used for near-surface geologic investigations and geotechnical, environmental, and archaeological studies. ASTM D6430-99(2010), Standard Guide for Using the Gravity Method for Subsurface Investigation, covers the equipment, field procedures, and interpretation methods for assessing subsurface conditions using the gravity method.
Seismic refraction measurements can also be used to map subsurface, geologic conditions to determine depth to bedrock, structure, and more. Archaeologists, geologists, and scientists involved in mineral, petroleum, or geotechnical explorations can look to ASTM D5777-00(2006), Standard Guide for Using the Seismic Refraction Method for Subsurface Investigation, for guidance on using this method.
Preliminary excavations at Tanis have already confirmed the presence of two of the pyramids gleaned from the infrared satellite images. According to the lead archaeologist involved in the discovery, the finding at Tanis could provide enough excavations for fifty generations to come. Perhaps these generations of Egyptologists will look to ANSI/ASSE A10.12-1998 (R2010), Safety Requirements for Excavation - a standard from ANSI member and accredited standards developer the American Society of Safety Engineers (ASSE) that defines safety requirements for open excavations made in the earth's surface.