What J-series message is for a subsurface track?

What J-series message is for a subsurface track?

• A. J3.4
• B. J3.0
• C. J3.1
• D. J3.2

Answer: (A)

J-series messages on Link 16 carry track information, and the J3 group handles track data. The specific variant used for subsurface (underwater) track is J3.4. This designation exists to separate underwater contacts from surface or air tracks, so each domain can be encoded with fields appropriate to that environment. Subsurface tracking involves data like depth and water-relative movement, which J3.4 is designed to convey, allowing platforms to interpret and filter underwater targets correctly without confusing them with surface ships or aircraft. The other J3.x variants handle other track domains, so they aren’t used for subsurface information.

J-series messages on Link 16 carry track information, and the J3 group handles track data. The specific variant used for subsurface (underwater) track is J3.4. This designation exists to separate underwater contacts from surface or air tracks, so each domain can be encoded with fields appropriate to that environment. Subsurface tracking involves data like depth and water-relative movement, which J3.4 is designed to convey, allowing platforms to interpret and filter underwater targets correctly without confusing them with surface ships or aircraft. The other J3.x variants handle other track domains, so they aren’t used for subsurface information.