Error in I/NAV word type 16 TOW

[odrisci]

It seems there is a problem in ubxtool when assigning a TOW to Word Type 16 in the E1 I/NAV.

There is a logic error here. According to the current OS SiS ICD (v2.0) word type 16 occurs at subframe index 7 and again at subframe index 14 (where subframe index 0 is the first page pair in the subframe). The current logic always assumes that word type 16 occurs at subframe index 7 (a 15 second TOW offset into the current cycle). It needs to be updated to account for word type 16 occurring at subframe index 14 (a 29 second TOW offset into the current cycle).

More generally, this approach is brittle, since the ICD makes no guarantees as to the ordering of word types within a subframe -- it might be worth considering using an alternative approach (maybe timing information from measurements??).