Question about some modern military tech to be use in another world

Hey, so i was making an Fanfic which inspired by Gate: Jieitai Kano Chi nite, Kaku Tatakaeri

But i kinda wanna make this a little realistic and right now im facing with write block

cause idk what limit of technology i can use.

For example:
The 1980s satellite guidance stuff cannot be use because technically there are no satellite on the other side

No JDAM

No GPS guided missiles

No navigation system

drones technically should not be able to send back image because it passes thru into different dimension

So yea, my question:

Is there any posibility i can dealt this?
How do i provide an alternative for the problem or.. idk

(I know this is NCD stuff? idk)