1.1.3 Backend Signal Processors

Several different types of spectrometers are/will be available at the SMTO:

• AOSs (Acousto-Optical Spectrometers)
• Filterbanks
• PI backends like the CHIRP.

Their characteristics are summarized in Table 1.4. The details of the spectrometers is discussed further in Chapter 5.

 

Table 1.4: SMTO Spectrometer Characteristics

 

Backend	# Channels	Res.[MHz]	status
AOSs
MPIfR 1 GHz (AOS A)	2048	1.021	online
MPIfR 1 GHz (AOS B)	2048	0.996	online
MPIfR 250 MHz (AOS C)	2048	0.4	online
Filterbanks (FBS)
256 MHz	256	1.0	online
64 MHz	256	0.25	online
8 MHz	128	0.0625	online
CHIRP
3 $\times$ 180 MHz	4100	0.044	expected late spring 2000
			PI - Hofstadter

Continuum data is processed with DRUMBEAT (Digital Recording Using Multichannel Backend with AT), a 64 channel backend derived from the Effelsberg 80-channel backend. See Chapter 3 for details.

The observer must tell OBST which backends to connect to which frontends (see chapter 5). Various options are possible, such as all backends going to one receiver or having two backends attached to one receiver and the others attached to a second receiver.

The software will keep track of the mode (line or continuum), depending on the type of observation requested and use the appropiate backend.