How do I characterise my window function?
Do please forgive me here as I am more a practical than theoretical person. I have invented a window function which I use prior to discrete Fourier transforms. My field is sound, and the window is designed to make accurate measurements from adjacent frequency bins.
For example, an asynchronous 1,000.1 Hz sine wave sampled at 48kHz for a 240 sample DFT will read with a level accuracy of better than 0.02dB in the 1,000 Hz bin but bleeds less than -60dB in adjacent bins (800 & 1,200). While a 1,001 Hz sine wave bleeds less than -40dB into the adjacent bins. A synchronous sine wave at 1,000 Hz bleeds less than -150dB into either adjacent bin.
I would like to describe its performance to compare it to other windows. Wikipedia provides graphs of bins against amplitude for window functions. How would I create such graphs? Are there better, more revealing ways of measuring how effective a window function is? I need a simple and patient explanation I'm afraid because as I said my mathematical knowledge is not great. Your help and patience is greatly appreciated.