Add instrument simulation

lisainstrument/instrument.py

@@ -765,7 +765,7 @@ class Instrument:
 
         logging.info("Generating clock noise time series")
 
-        if self.clock_freqlindrifts[sc] == self.clock_freqquaddrifts[sc] == 0:
+        if self.clock_freqlindrifts == self.clock_freqquaddrifts == 0:
             # Optimize to use a scalar if we only have a constant frequency offset
             self.clock_noise_offsets = ForEachSC(lambda sc:
                 self.clock_freqoffsets[sc]