low pass digital filters


idl routines
03oct13:plot filter shapes and aliased power. dec=2..15
02may08: simulate lpdf, look at rms vs decimation.

       The mock spectrometer has a low pass digital filter after the a/d, digital mixer section. The filters are 8x overlap filters that are symmetric about DC. The decimation can be 2 through 1024. The coef's for a particular decimation:
The filter types available are:     The filters are generated with jeffs program (pnet_mkdlpf_coeff).

IDL routines:

    Some idl routines used with the dlpf  processing:


03oct13:plot filter shapes and aliased power. dec=2..15

    Plots were made of the filter shapes (in the time and frequency domain) for decimations 2 through 15 using the filter coefficients. 
The plots show:

LPDF filter shapes and aliased power
2 (.ps) (.pdf) 7 (.ps) (.pdf) 12(.ps) (.pdf)
3 (.ps) (.pdf) 8 (.ps) (.pdf) 13(.ps) (.pdf)
4 (.ps) (.pdf) 9 (.ps) (.pdf) 14(.ps) (.pdf)
5 (.ps) (.pdf) 10(.ps) (.pdf) 15(.ps) (.pdf)
6 (.ps) (.pdf) 11(.ps) (.pdf)

processing: x101/pdev/dlpf/simDlpf.pro

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