Spectral Window Specification Syntax

Spectral windows (SPW) specification can be a single ID or a list of spectral window integer IDs, a spectral window name (as a literal string (for exact match)/regular expression/pattern) or a reference frequency value (value with a unit). A single frequency specification is used for exact match with the REF_FREQUENCY column of the SPECTRAL_WINDOW sub-table. A range of frequencies are used to select all SPWs which are within the given range. The allowed units are Hz, KHz, MHz, GHz or THz.

SPWs can also be selected via a boolean expression for integer IDs.

• "$>$ID" will select all SPWs with ID greater than the specified value.

• "$<$ID" will select all SPWs with ID lesser than the specified value.

• "$>$FREQ" will select all SPWs, the reference frequencies of which are greater than the given frequency converted to Hz.

• "$<$FREQ" will select all SPWs, the reference frequencies of which are greater than the given frequency converted to Hz.

E.g.

• spw=1,2,3 selects spectral window IDs 1,2 and 3
• spw=1;2;3 same as above. This style can be used along with CHANSPEC
• spw=1$\sim$3 same as above
• spw=327MHz selects spectral window with a reference frequency equal to 327.0 MHz
• spw=327$\sim$610MHz selects all spectral windows with reference frequencies in the range [327.0, 610.0] MHz.
• spw=1421MHz, 1422MHz, 1423MHz selects SPWs with reference frequency 1421.0, 1422.0 and 1423.0 MHz.
• spw=1421MHz; 1422MHz; 1423MHz same as above. This style can be used along with CHANSPEC.
• spw=$>$327MHz selects all spectral windows with reference frequency greater than 327.0 MHz
• spw=$<$327MHz selects all spectral windows with reference frequency less than 327.0 MHz