DIY Instruments for Amateur Space

Chapter 7. Resolution, By the Numbers

Assume an ideal detector. Ideal = perfect 100% fidelity; thus it only returns data intrinsic to source with no noise, has perfectly square pixels, and there are no optical defects, lens flare, etc. That is, it’s the sensor equivalent of physics frictionless vacuum.

Your target is a star with a possible exoplanet. Your detector receives 52 photons. We presume that’s what your detector of a given size captures for the entire exposure. What happens when we try to catch it with different imaging detectors? Remember, no matter how we slice it, we only get 52 photons.

Detector Bins

Those 52 photons are incident on a single detector (say, 1cm×1cm). It is divided in this example into pixels. Each pixel is like a little ...