Hi this is usually worked out for you on your annual salary. Your gross is self explanatory, your net is your gross less twice oap yearly rate. This amount combined gives you the annual amount so divide this by 26.09 if paid fortnightly. That gives the amount for 1 year. You could either multiply the rates by 16 or the combined amount by 16 to get the actual amount. 16 years is a lot as notional service can be comparatively expensive.
On the spouse & children's your spouse and children would get benefits based on what your own pension entitlement would have been should you die in service. I have more specific details on this in work so I'll post them then.