Simon Dawes Artemis 285

Kit

Assembly

The Completed Camera

Problem 1 Thermal readout noise Solution: 1.New Peltier 2.More thermal paste on peltier (although Dark subtraction was quite effective)

Problem 2 Dust donuts! Solution: Flat fielding Light box (although they can sometimes be removed with clever processing)

Problem 3 & 4 Gradient from top left to bottom right Solution: Turn off Amp during exposure (Latest software always selects this for long exposures) Weird patterns! – Dew on CCD Solution: Seal the cold frame, desiccant was trying to dry the whole Earth! CCD was dripping wet

Problem 5 (will they ever stop) Another weird pattern! - Frost Solution: Thermal paste sealing CCD window, to warm the window slightly

Flat field light box

Raw 15s Frame, note top-bottom gradient and dust donuts

Stacked, dark subtracted, cube route scaled, de-convolved

Notice dust donuts (poor flat field) and sky gradient going from top left to bottom right

Median rank operator removes small scale structure, leaving the sky gradient, donuts and Globular

19,000 is added to every pixel in original image

One Image is subtracted from the other, removing gradient and donuts

Background is smoothed to remove some noise

Any pixel value less than 21,000 ADU is set to 17,000ADU

Black and white levels are adjusted