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   HaloSim3 Software 

   All the website simulations were produced by HaloSim. It may be freely downloaded.

It creates simulations by accurately tracing up to several million light rays through mathematical models of ice crystals.

HaloSim3 is the result of a transatlantic collaboration by Les Cowley and Michael Schroeder.

    • Simulations can be run immediately. Select from ready to run simulations of common and rare halos with text descriptions.

    • Crystals. Halos from all crystals are simulated; hexagonal plates, columns, pyramidals and non water-ice crystals which might be found in other planetary atmospheres.

    • Orientations. Files for plate, singly oriented columns, Parry and Lowitz orientations included. Others can be generated. Axial dispersions and dispersion distributions can be specified.

    • All halos simulated. All the possible light paths through crystals are sampled, hence all halos for a given solar altitude and crystal type/alignment are simulated.

    • Complex halo displays are simulated. HaloSim simultaneously computes up to twelve crystal-orientation combinations.

    • Ray filtering and tracing tools allow particular halos to be isolated and their formation investigated.

    • Crystal tool kit Tools to automatically generate custom crystal orientation files and pyramidal crystals of any proportions.

    • Fisheye, plan and camera projections centered on the zenith, nadir, sun or a user defined position. Views can be zoomed.

    • High definition graphics. Full colour, grey-scale simulations against backgrounds of choice. Also traditional black dots on white.

    • Simulations parameters stored. The simulation parameters can be stored with a text description for subsequent retrieval. Settings, including zoom conditions and colours, are restored on playback.

    • Custom interface settings. Control appearance and behaviour can be set by the user.