Pulsar synthesis

A simple pulsar synthesiser will have at least the following control parameters  

In the folder pulsar in the Macintosh portion of the accompanying CD-ROM there is a demo version of PulsaiGenerator, a terrific pulsar synthesiser implemented by Alberto de Campo and Curtis Roads at the University of California, Santa Barbara. 

---

Pulsar synthesis, as recently proposed by Curtis Roads (2001), shares the same fundamental principles of granular synthesis. The main difference is that the concept of sound grains is replaced by the notion of pulsars. In essence, a pulsar is a sound grain with a variable duty cycle an idea inspired by an analog synthesis effect known as pulse-width-modulation (PWM). More specifically, a pulsar consists of a waveform w (or pulsaret) of duration d followed by a silent portion s (Figure 5.12). The period p of a pulsar is therefore given by the sum of H7 + s, and d corresponds to the duration of its duty cycle. The frequency of a stream of pulsars with period p is calculated as 1/pHz. 

Figure 5.14 Pulsar synthesis scheme. Note that the convolution of a pulsar stream with a brief sound sample replaces the original pulsar on the stream by a filtered version of the sample...

Pulsar Generator (or simply PG) designed by Alberto de Campo and Curtis Roads, implements the Pulsar synthesis technique discussed in Chapter 5 it runs on Macintosh computers. 

A quick-start overview of the system is given in the document PG ManualWord98 that is available within the PG materials. Fairly informative documentation is also provided via the program s own Help facility, including a complementary introduction to the Pulsar synthesis technique. 

M. Ryle and A, Hewish (Cambridge) pioneering research in radioastrophysics Ryle for his observations and inventions, in particular of the aperture-synthesis technique, and Hewish for his decisive role in the discovery of pulsars. 

Ryle, Sir Martin (1918-84) British radio astronomer, who became professor of radio astronomy at Cambridge University in 1959. He organized three surveys of celestial radio sources and developed the technique of aperture synthesis (seeradio telescope). In 1974 he shared the Nobel Prize tor physics with Antony Hewish (1924- ), who led the team that discovered pulsars. 

---