Question

Suppose you are observing with a 1024x1024 CCD. How many pixels are there? If the CCD can distinguish 2^20 ( about 1 million) different brightness levels, how many binary data bits are there in one image? Suppose you obtain one image every 6 minutes for a 10hr night ; how many digital data bits must you store for later processing?

Answer 1

a) For a 1024x1024 CCD, there are 1 MegaPixel or 1 million (2^20) pixels as 1024=2^10.

b) Each pixel of CCD can distinguish between 2^20 different brightness levels and there are 2^20 pixels.

So combined number of various brightness levels = 2^20 * 2*20 = 2^40

Hence, the binary bits in one image = 40.

c) Minutes in 1 hour                   =   60

Image obtained in 6 minutes                           =   1
Image obtained in 1 hour (60 minutes)           = 60 / 6
Image obtained in 10 hour (600 minutes)       = 600 / 6
                                                                        = 100

Bits required to store one image = 40
So, bits required to store 100 images = 40*100
                                                            = 4000