While imaging, photometry and spectroscopy have become routine tools to study planetary surface, a number of questions remain open concerning the interpretation of such observations. The goal of the session is to present progresses in numerical methods to extract relevant information from spectroscopy in solid phase, reference laboratory data bases, photometric modeling,mixing/unmixing methods... Applications will encompass both small bodies and planetary surfaces, and UV to far IR ranges. Usual software and web service applications are welcome.