(Arecibo radio-telescope instrument aimed at observing pulsars)
PUPPI (Puerto Rican Ultimate Pulsar Processing Instrument)
was a back end instrument instrument for the Arecibo Telescope,
working in conjunction with one of the telescope's receivers,
to observe pulsar timing over a wide (800 MHz) band.
It was a project of National Radio Astronomy Observatory (NRAO) and was a clone of GUPPI.
The Arecibo Telescope ceased operation in late 2020.
I'm not sure if PUPPI was used as recently as 2020: for all I know,
it may have been retired earlier.