Ratio of reflected to total flux in the WISE short-wavelength bands W1 (top row) and W2 (bottom row) vs. heliocentric distance predicted by the NEATM for different values of visible geometric albedo (p_V), and beaming parameter (η) increasing from left to right. A typical value of 1.4 was chosen for the infrared relative reflectance or albedo ratio (R_X ≡ p_X/p_V, with X = W1, W2; see, e.g., Alí-Lagoa et al. 2013 for more details). All other things being equal, a higher η means a lower surface temperature and hence a higher reflected light contribution. For main-belt asteroids, the average η-value is 1.0.