Why the opposition spikes of regolith-like media are
usually sharp and do not show rounding off
Yu. Shkuratov*,1, V. Psarev1, D. Stankevich1, A. Ovcharenko1 and G. Videen2
- 1 Astronomical Institute of Kharkov V.N. Karazin National University, 35 Sumskaya Str. Kharkov, 61022, Ukraine.
- 2 Research Laboratory AMSRD-ARL-CI-EM, 2800 Powder Mill Road Adelphi Maryland 20783 USA.
For particulate surfaces the slope of photometric phase curves must be zero at zero phase angle, otherwise the Maxwell equations are violated. In experiments such surfaces usually reveal sharp opposition spikes; however, we found samples that show tendency to have rounded phase functions. We also show that blocking of reciprocal trajectories at coherent backscattering could influence the rounding.
- * Corresponding author