Version 2.3 -- 31 March, 2011 (GT2 -- call opening update)
Chapter 5 -- Updated information on spurs and representation in HSpot v5.3.
Chapter 6 -- Complete update of screenshots and examples using HSpot v5.3.
Version 2.2 -- 20 January, 2011 (GT2 -- call opening)
Chapter 3 -- Tsys plot updates for bands 4 (correction) and 5.
Chapter 5 -- spur list updated in section 5.4.6.4.
Chapter 5 -- additional spectral purity information in section 5.4.6 from original release note.
Version 2.1 -- 15 December, 2010 (AO1 -- start of observations)
Beam profile updates in Table 5.4
Beam efficiency measurements based on in-flight experience in Table 5.5
Chapter 5 -- description of application of efficiencies in HIFI standard pipelines
Chapter 5 -- updated section on spurs in band 1a, now removed in current HIFI operations
Chapter 5 -- error budget table(s) updated.
Version 2.0 -- 20 May, 2010 (AO1)
Substantial changes, mostly based on in-flight experience.
Chapter 1 -- included some latest results
Chapters 3 to 5 -- completely updated based on changes to observing modes and calibration information obtained in-flight.
Chapter 6 -- changed figures to match changes in HSpot front end. Examples remained substantially unaltered.
Version 1.1 -- 14 May, 2007
Updated sensitivity figure 3.3 in section 3.4.1
Updated section 4.2.2.3 (on cross map) to include the mode changes recently incorporated -- availability of selectable cross step size.
Changed figure 6.2 to new HSpot front end
Updated section 6.2.1.1 to indicate new save and load facilities from instrument and frequency settings for HIFI
Updated section 6.2.2.3 to include information on storage of time estimates in AOR files
Changed figures 6.19, 6.27 and 6.32 to show updated front end for HIFI HSpot instrument settings.