Re: ListCorrelate on lists with different sampling rates
- To: mathgroup at smc.vnet.net
- Subject: [mg87399] Re: ListCorrelate on lists with different sampling rates
- From: "jwmerrill at gmail.com" <jwmerrill at gmail.com>
- Date: Wed, 9 Apr 2008 05:57:50 -0400 (EDT)
- References: <ftfell$bv7$1@smc.vnet.net>
On Apr 8, 5:42 am, Curtis Osterhoudt <c... at lanl.gov> wrote: > Hi, all, > > I've been beating my head against this problem (only half an hour at a > time, though, which may well be my mistake) for a little while now, and was > wondering if people had some input. > > I'm basically looking at the cross-correlation (or sliding dot-product) of > two sampled (discrete) signals---one a drive signal and one a received > signal---to pick out various features. I'm doing this using Mathematica's > ListCorrelate, which is working admirably, and I can easily pick out echoes > and so on. > > However, my question concerns what to do when the sampled signals have > different time scales. As I understand it, the ListCorrelate function really > only works (for this application) when the input lists are one-dimensional. > If the sampling rates are different, I can go ahead and (for example) > resample the higher-sample-rate signal (via interpolation) to the same rate > as the lower-sample-rate signal, and then perform the ListCorrelation. It > seems to me, though, that I'm sort of throwing away some information that I > don't need to in the resampling procedure. > > Is that the recommended procedure, or is there something more clever I can > do? > > ========================================================== > Curtis Osterhoudt > cfo at remove_this.lanl.and_this.gov > PGP Key ID: 0x4DCA2A10 > Please avoid sending me Word or PowerPoint attachments > Seehttp://www.gnu.org/philosophy/no-word-attachments.html > ========================================================== Interpolate the data sampled at the lower rate up to the higher rate?