Neil Bowles

Abstract:

Understanding how the surfaces of airless planetary bodies—such as the Moon—scatter visible light enables constraints to be placed on their surface properties and top boundary layer inputs to be set within thermal models. Remote sensing instruments—such as Diviner onboard the Lunar Reconnaissance Orbiter—measure thermal emission and visible light scattering functions across visible (∼0.38–0.7 µm) to thermal infrared (TIR) wavelengths (∼0.7–350 μm). To provide ground support measurements for such instruments, the Oxford Space Environment Goniometer (OSEG) was built. Initially, the OSEG focused on measuring TIR directional emissivity functions for regolith and regolith simulant samples in a simulated space environment, but it has recently been modified to measure visible wavelength Bidirectional Reflectance Distribution Functions (BRDFs) of samples in ambient conditions. Laboratory-measured BRDFs can be used (1) to test and to help interpret models—such as the Hapke photometric model—and (2) as visible scattering function inputs for thermal models. This paper describes the modifications to and initial calibration measurements taken by the Visible Oxford Space Environment Goniometer with a 532 nm laser, and details how this setup can be used to measure BRDFs of regolith and regolith simulant samples of airless planetary bodies.

Abstract:

Spectral data created as part of a study into the effects of aqueous and thermal alteration on the spectral signature in the NIR and MIR wavelength ranges. NIR data were collected as reflectance and MIR data were collected as emissivity under both ambient and simulated asteroid environment (SAE) conditions.

Abstract:

Position sensitive detector X-ray diffraction (PSD-XRD) data created as part of a study into the effects of aqueous and thermal alteration on the spectral signature in the NIR and MIR wavelength ranges. Data were collected on an Enraf-Nonius PDS120 X-ray diffractometer with an INEL curved 120o PSD. Each meteorite had two diffraction patterns collected on two 50mg aliquots (HB1 and HB2) of a larger 1.8g mass powdered sample.