Usages of "up" in the context of military dialogues

Question

The following two dialogues are taken from the subtitles in the famous first-person shooter video game -- Crysis:

Strickland: Team Idaho, this is command, we’re pushing up the valley all the way to the mine. Repeat: phase line is the mine. Expect heavy resistance from KPA armor up₁ ahead.

Strickland: Air command, this is Strickland. What’s the word on that air support? Over.

Pilot: That’s a no go, sir. Airspace is not yet secure. Our jets are occupied with strategic targets on the other side of the island. Air support’s on hold until further notice.

Strickland: Copy that, we’ll have to do this the hard way.

Strickland: All units, this is Major Strickland. Air support is on hold. Push ahead to phase line alpha. Let’s go! Let’s go!

&

Pilot: Vulture twelve beginning approach, we’ll take up a covering pattern and provide air support. Over.

Strickland: Nomad, take the front line, we’re advancing up₂ the village to the mining complex.

Strickland: Keep the pressure on, marines. KPA forces are retreating up₃ the valley. We’re pushing through all the way to the mine.

Marine 1: You heard the man, move out!

Strickland: Push ahead to the mine, Nomad.

Nomad: Idaho Command, the ground ahead is ripped apart.You’ve gotta get earth movers up₄ here from the harbor before you can advance.

Strickland: Solid copy, Nomad. You’re on your own until otherwise advised.

I think up₁ has the sense of "to the place where somebody/something is", the 3rd definition in the entry for "up" (adverb) in OALD;

up₄ have the sense of "towards or in a higher position", the 1st definition in the entry for "up" (adverb) in OALD;

up₂ and up₃ has the sense of "along or further along a road or street", the 2nd definition in the entry for "up" (preposition) in OALD. In this case, up could be substituted with through, along or down.

Is my understanding correct?

Answer 1

The American military (which this portrayal is based on) does not usually take elevation into consideration with regards to navigation and location unless it's important for some outstanding reason. They use maps organized into grids, and that's usually how they make reference of locations. They also use the hands of a clock (1 through 12 o' clock) and degrees of a circle (with 0 degrees being north) to convey direction.

Thus, the American military almost never uses common relational directions such as up, down, left, or right. "Up" in this context means "forward" -- which is to say, towards enemy territory, or towards the speaker's objective, which is usually the only relational direction the military uses. Other directions are too relational to be used in the military, but entire battalions can relate to "towards the objective." "Retreating up the valley" means they're going back the way they came through the valley. The 4th "up" ("up here" from the harbor) is a more common colloquial phrase. It doesn't really mean anything different from "here;" it doesn't even imply that the "earth movers" are below the speaker to begin with. It's usually used in the context that someone or something else is moving towards "here" from some distance, which is obviously quite broad.

Answer 2

"Up" is kind of curious in my mind. First of all, I agree with Tetsujin, you'd never say "down ahead" but the opposite of "up ahead" is "back behind". I don't know why it's not "down behind" but such are the curiosities of the English language. "The planes are coming from back behind enemy lines".

Also, "up" seems to have a kind of relation with north and south sometimes. My brother lives and hour south of me and I go "down" to his place or he comes "up" to mine. It would feel strange somehow for me to go up to his place or for him to come down to mine because I live north of him.

Sometimes it has to do with height - "come on up" if you're going to a place of higher elevation or "come on down" if you're moving to a place of lower elevation.

If precise elevations are not obvious then either of them seem to work though "come on up" seems to have a connotation of improving your situation, "come on down" doesn't seem to have a particularly negative connotation.

In a similar way, financial success is often called "moving up in the world" but there really doesn't seem to be a "moving down in the world" as its opposite.