NOTES on finding a "control" control can be virtual or derived from an actual source. single photon resolving or "photon-to-photon" matching for a given control source to the "ideal" lens is needed in the case of an actual source. for a virtual source the control photon "output" is a under given conditions is left to best guessing and matching with less than ideal lenses accuracy = (virtual source <----> actual source) accuracy = 1/(virtual source - actual source) ---------------------------------------------------------------------------------------------------------- What to use for control sources? Control sources cannot obviously be stars (though they can be used for feedback and in many other cases). Extremely faint, low intensity sources like stars can be simulated virtually by deriving their intensity levels, spectral signatures, etc. from current data sets. Re-computing with more accurate maps and feeding back to the control will begin to compound accuracy as well. ---------------------------------------------------------------------------------------------------------- What is the "virtual source"? A virtual source is determined by simulating the effects of photons hitting a specific cell under specific conditions. The popular ray tracing packages in many ways provide a "ready-made" environment. cell characteristics photon stream (light) characteristics The better these can be determined, the more accurate the model, the better the "fitness" constraint, and the better the GA works. ---------------------------------------------------------------------------------------------------------- What about an "actual" control source? The next step after a virtual control is an actual control. This insures the hardware (ie. CCD) is working properly. Incandescent bulbs, neon lamps, the sealed "dark" container, etc. can be designed in various timing configurations with CCD chips to do photon counting and precise intensity measurements. ---------------------------------------------------------------------------------------------------------- Matching a CCD "cell" area (or photodiode/pixel) with a specific control This is determined by, among other factors, the position of the CCD cell. After all, the "ideal" configuration of the cells to pick up the maximum number of photons from the source if what we're after, isn't it? Doing it virtually: Anyways, each cell (or photodiode/pixel) has a unique control. Each cell control data picks up a different section of the source from a different angle: Cell (CCD) Array | The Source |<------------ angle | & * * | dimensions * |<------------ covered vary | ---------------------------------------------------------------------------------------------------------- Data Synthesis of all the elements is the next "layer" or order here... more forthcoming... ---------------------------------------------------------------------------------------------------------- (c) GPL, Freeware, S.A. Thigpen, http://telescope3d.sourceforge.net