Category Archives: vibrometry

FM and PM Modulation Spectrum (interactive)

This lit­tle wid­get will cal­cu­late the spec­trum for var­i­ous mod­u­la­tion sig­nals with arbi­trary fre­quen­cy and ampli­tude and explain why it looks the way it does.

the Doppler effect (relativistic)

Chris­t­ian Doppler in 1942 pre­dict­ed the Doppler effect for all kinds of waves, not only sound waves. The Doppler effect for light was demon­strat­ed in 1948 by Fizeau. In con­junc­tion with the arti­cle on the clas­si­cal Doppler effect, as it occurs e.g. for sound waves, we will here exam­ine the rel­a­tivis­tic Doppler effect which is […]

the Doppler effect (classical)

The Doppler effect is noth­ing real­ly new. It’s well-known that Doppler fre­quen­cy shift occurs for sound as well as light; there are, how­ev­er, some sub­tle dif­fer­ences between the two, owing main­ly to Einstein’s spe­cial the­o­ry of rel­a­tiv­i­ty. This arti­cle describes the clas­si­cal Doppler effect as it occurs e.g. for sound waves and in which the […]

Basics of Doppler Vibrometry

This post has been over­due for quite a while now. I orig­i­nal­ly intend­ed to post some­thing about what I do at work soon after I start­ed my new job. That was more than a year ago; time real­ly does fly. Some­how there was always some­thing else already in the pipeline and I nev­er got around […]