MMT-Cam: A New Miniature Multispectral Thermal Infrared Camera System for Capturing Dynamic Earth Processes

Abstract

We have developed a new portable, ground-based imaging system primarily to investigate the thermal properties of volcanic processes during lava propagation and cooling, although it is potentially applicable to any dynamic geologic process. The miniature multispectral thermal camera (MMT-Cam) is an imaging system that acquires six wavelength bands of thermal infrared (TIR) data between 8 and $12~\mu \text{m}$ nearly simultaneously. The spatial and temporal resolutions of the camera system are high, $640 \times 512$ pixels, and 1 s, respectively. The imaging system is calibrated using full-aperture blackbody experiments at a range of temperatures from 283 to 1023 K to account for all instrumental, optical, and transmission effects. In addition, the baseline drift due to changing internal camera temperature is measured and removed. As a result, the accurate multispectral TIR image data are acquired of dynamic surfaces such as propagating and cooling lava flow surfaces captured at the critical temporal (seconds) and thermal (initial rapid cooling) scales. These improved acquisition parameters provide valuable data for both compositional and textural spatiotemporal variability analyses of these volcanic surfaces. Furthermore, the MMT-Cam specifications are designed to be comparable to current and proposed Earth-orbiting TIR instruments to better evaluate the potential for future TIR data sets to deliver similar data sets.