Method of modeling and simulation of shaped external occulters

An external occulter system, the system comprising:

• at least one processor executing program code, said program code including the steps of:
• providing an external occulter having a plurality of petals, said occulter being coupled to a telescope;
• and
• propagating light from said occulter to a telescope aperture of said telescope by scalar Fresnel propagation, by:
• obtaining an incident field strength at a predetermined wavelength at an occulter surface;
• obtaining a field propagation from said occulter to said telescope aperture using a Fresnel integral;
• modeling a celestial object at differing field angles by shifting a location of a shadow cast by said occulter on said telescope aperture;
• calculating an intensity of said occulter shadow on said telescope aperture;
• and
• applying a telescope aperture mask to a field of said occulter shadow, and propagating said light to a focal plane of said telescope via fast Fourier transform (FFT) techniques,
• wherein a focal plane of said telescope is separated into a plurality of channels using beamsplitters;
• and
• wherein one or more beam spots from said laser beacons are acquired using a coarse acquisition channel of one of said plurality of channels;
• wherein a lateral location of said occulter is sensed using a pupil imaging channel of another of said plurality of channels;
• and
• wherein a fine acquisition channel of another of said plurality of channels, is used to fine sense said location of said occulter.

A non-transitory computer-accessible medium having a program which contains executable instructions, the program comprising the steps of:

• providing an external occulter having a plurality of petals, said occulter being coupled to a telescope;
• and
• propagating light from said occulter to a telescope aperture of said telescope by scalar Fresnel propagation, by:
• obtaining an incident field strength at a predetermined wavelength at an occulter surface;
• obtaining a field propagation from said occulter to said telescope aperture using a Fresnel integral;
• modeling a celestial object at differing field angles by shifting a location of a shadow cast by said occulter on said telescope aperture;
• calculating an intensity of said occulter shadow on said telescope aperture;
• and
• applying a telescope aperture mask to a field of said occulter shadow, and propagating said light to a focal plane of said telescope via fast Fourier transform (FFT) techniques;
• acquiring one or more beam spots from said laser beacons using a coarse acquisition channel of one of said plurality of channels;
• sensing a lateral location of said occulter using a pupil imaging channel of another of said plurality of channels;
• and
• using a fine acquisition channel of another of said plurality of channels, to fine sense said location of said occulter.

An occulter acquisition system, the system comprising:

• a telescope;
• an external occulter having a plurality of petals, said occulter being coupled to said telescope;
• a plurality of laser beacons mounted at bases of said plurality of petals of said occulter, said laser beacons being pulse code modulated at a different temporal frequency;
• a plurality of beamsplitters provided in said telescope, which separate a focal plane of said telescope into a plurality of channels;
• wherein said plurality of channels include a coarse acquisition channel which acquires one or more beam spots from said laser beacons, a pupil imaging channel which senses a lateral location of said occulter, and a fine acquisition channel which fine senses said location of said occulter.