Pre-Meeting Workshop

Monday, September 21

Workshop Option 1

Using the Moon as a Radiometric Calibration Reference

Tom Stone, U.S. Geological Survey

To meet tighter calibration requirements for space-based Earth observing systems, the option of using the Moon as an on-orbit calibration reference has received increased interest. Taken to its full development potential, lunar calibration can achieve sub-percent absolute radiometric accuracy post-launch, and enables a number of unique and important on-orbit calibration capabilities such as reference inter-calibration against high-accuracy benchmark sensors. This workshop provides practical information on using the Moon as a radiometric reference, with a focus on reflected-solar wavelengths. It is designed to help instrumentation scientists/engineers and mission developers who are tasked with calibrating sensors against the Moon. The presentations will cover topics of lunar calibration system development at USGS and operation of the ROLO lunar irradiance model; performance evaluation of the current model-based reference; tips for obtaining accurate lunar calibration measurements from imaging instruments; and requirements for new characterization measurements of the Moon, which are needed to refine the lunar reference and also offer opportunities for developing and applying new measurement technologies. The discussion will include recent advances in lunar calibration system development, including novel approaches to modeling and the potential to extend the range of validity in terms of phase angle and expanding wavelength coverage to other spectral regions.

Workshop Option 2

Integrating Spheres

Chris Durell, Labsphere

The first part of this workshop will cover the basic physics of Lambertian materials and integrating spheres and provide a practical understanding of the “rules of thumb” for sphere design based on the use-case. Course material will cover many common applications such as light measurement, laser power measurements, reflectance and transmittance measurements, quantum efficiency and other uses focusing on new users and practical applications. The second part of the course is focused on using integrating spheres as uniform sources and ultimately, as absolute calibration references. Discussion will move from theory to practice and specifications. Case studies on real satellite calibration with world-class uncertainties will be given with the experts involved in these projects.