SEP proton intensities as a function of time at 1 AU. The green dashed curve shows 6-10 MeV SEP proton intensities observed during a solar eruption on Nov. 3–4, 2011, at SOHO (top left panel), STEREO B (top right) and STEREO A (bottom left) spacecraft. The blue and red curves show the 10 MeV proton intensities simulated using the FP and FP+FLRW models, respectively, using an impulsive injection at flare maximum, t₀ = 22:41 – 500 s UT on Nov. 3 (dashed vertical line) at the flare longitude. The spacecraft locations are shown in the bottom right panel by filled green circle, yellow triangle, and blue square for SOHO, STEREO B, and STEREO A, respectively. The blue arrow denotes the SEP injection longitude, the thick solid line and red circle are the same as in Fig. 3, and the dashed curves show the Parker spiral field-lines connecting the spacecraft to the solar surface.