Table of Contents

Wideband Fast Fourier Transform Spectrometer (FFTS2)

Originally acquired for the CASIMIR instrument intended for SOFIA, a new FFT spectrometer (FFTS2) is now available with the wide band heterodyne receivers. At present, FFTS2 has two IF modules and four FFT modules. Each IF module divides a 4 GHz wide IF band (4-8 GHz) into two 2 GHz sub bands. In turn, each sub band is sampled with 8192 channels by an FFT module. The FFTS2 can be operated simultaneously in parallel with the other FFT spectrometer, FFTS1.

FFTS2 Specifications
Signal processing Non windowed FFT
Sub band width 4 x 2000 MHz
Channels 4 x 8192
Channel spacing 269 kHz [0.350 km s−1 at 230 GHz]
Channel response sinc2


Sub band assignments

Receiver Sub
230 GHz B1 4-6
B2 6-8
460 GHz B3 4-6
B4 6-8
(345 GHz)
B1 4-6
B2 6-8
subband channels
B1 1– 8192
B2 8193–16384
B3 16385–24576
B4 24577–32768

UIP commands

Data analysis