Modified algorithm for UVIT frames

Make a table (dimentions 4x1000) for Poisson statistic. x-axis is average photons at a pixel P_ij and Y-axis is the number of photons. X-axis values range from P_ij = 0.001, 0.002,... 1.000, in steps of 0.001 (1000 values). Y-axis has 4 values, which are equal to probabilities of number of photons incident = 0, 1, 2, 3.

For example: at x = P_ij = 0.1, the four values (corresponding to probability of 0, 1, 2, and 3 photons incident on that pixel) are P₀ = e^-0.1 (= 0.9048), P₁ = 0.1 P₀ (= 0.09048), P₂ = 0.01 P₀/2 (=0.0045242), and P₃ = 0.001 P₀/6 (= 0.0001508).

For a given frame_k, find a random number R equally distributed between 0 and 1. For each pixel

1. If R <>0, then number of photons for that pixel = 0.


2. If (P₀ + P₁) > R > P₀, then number of photons = 1; and if (P₀+P₁+P₂) > R > (P₀ +P₁) then number of photons is 2; and so on.
   

For the next frame, compute a new random number R and repeat the above steps again...