I have just figured out why my volume calculations, with the exception of
the TL-9 Basic
package, have been off. The third column tag is Min Length on the QSDS 1.5e
Standard
Sensor Systems Table. The explanation note says that this is "the length of
the shortest hull
that can mount the sensor in meters. This detail can be safely ignored for
almost any hull
in this version of the QSDS system."

The min length is for a HRT or PEMS "folding" antenna and the calculations
for the
packages are for a fixed antenna.

Using TNE FF&S Mk I Mod 0 a folding array is required when the HRT or PEMS
antenna
diameter in meters is greater than the hull length (unmodified by
configuration). A fixed
antenna modified the antenna volume by 0.05, while a folding antenna's
modifier is 0.1.

A 90,000 km HRT has an antenna diameter of 20 m that on a 100 Td hull with
a unmodified length of 14 m requires a folding array which kicked my total
package
volume to 5 Td instead of the 4.5 TD in the table. Using the fixed antenna
volume
modifier of 0.05 my calculations matched.

My recommendation is to change the table Min Length data to match the
antenna
diameter in TNE FF&S Mk I Mod 0 for the HRT in TL-9 and the PEMS in TL-10+.

An alternative would be to recalculate all of the values based on a folding
array.

In my opinion the easiest approach would be to change the min length to
match those
in the HRT and PEMS antenna diameters and insert in the Explanation of
columns that
the min length is for a fixed antenna being mounted on the hull.

Tom Rux