Invasion Advice Needed

[DoctorDanny (OP)]

I've discovered this Paradise system. Lot's of habitable planets, plenty o'  resources and unfortunately some ugly aliens.

I've succesfully executed operation 'Ridiculous Amounts of Ordnance'  at their 4 ship fleet and I now have 4 shiney wrecks in orbit of a lovely inviting moon.

Problem is though, besides the Alien Ruins that I'm interested in they seem to have an Alien population on the planet (yuck).
How can I tell how strong their forces are and what to bring?
Since they haven't shot down my survey ships I'm assuming no STOs, so landing would be relatively safe yes?

Am I correct in thinking that I need an ELINT ship in orbit?

[Person012345]

To simply detect the ground forces and their (approximate?) size all I needed was an active sensor.

[DoctorDanny (OP)]

I invaded the planet with some 20k Heavy Assault Infantry, supported by 200 tanks.

Enemy forces were defeated in one round, without a shot being fired.
Is there any way to figure out what these forces were?

[Doren]

You could still have the event messages of killed units summary if you set your event message to show more

Edit. It could also be that there were no ground forces and that's why you did not notice the approximate ground troops count

[the obelisk]

I invaded the planet with some 20k Heavy Assault Infantry, supported by 200 tanks.

Enemy forces were defeated in one round, without a shot being fired.
Is there any way to figure out what these forces were?

I had something like this pop up recently as well.  I didn't invade right away, and had ELINT and other sensors nearby for quite a while, and found that
a) they had no installations
b) no ships showed up to interact with them over what I think was a couple decades of observation
so I guess they spawned as conventional/pre-TN?  I don't know if that would prevent them from having ground units though.

[Ametsala]

I invaded the planet with some 20k Heavy Assault Infantry, supported by 200 tanks.

Enemy forces were defeated in one round, without a shot being fired.
Is there any way to figure out what these forces were?

What does the Intelligence and Foreign Relations screen say? It should list all known ground unit classes, as well as all other info gathered.

I didn't need ELINT modules to get info.  Just blasting the xenos was sufficient.

[DoctorDanny (OP)]

It seems they had no ground forces at all.
The diplomacy screen only shows ships and population, no ground forces are known.

It was a precursor outpost with 4 ships and some planet based infrastructure to support them (ordnance and fuel).

[Froggiest1982]

It seems they had no ground forces at all.
The diplomacy screen only shows ships and population, no ground forces are known.

It was a precursor outpost with 4 ships and some planet based infrastructure to support them (ordnance and fuel).

They may have suffered the ground unit disappearing bug?

[Morrigi]

This sounds very similar to some of the precursor outposts in VB6. They'd persistently pop up as a sensor contact until you invaded them, at which point they'd flip with no resistance. It may well be intended behavior.

[Droll]

This sounds very similar to some of the precursor outposts in VB6. They'd persistently pop up as a sensor contact until you invaded them, at which point they'd flip with no resistance. It may well be intended behavior.

It is WAI, sometimes they have garrisons other times they do not.