Ukraine war: Exposed unit is taking huge risks in fight against Russia - without them artillery crews would be firing blind

Their route into the tree line, which runs along an open field, is littered with shell casings and unexploded rockets.

There are massive craters everywhere.

The fighting in Kherson has been ferocious but Ukraine is making steady gains, which is leading to Russia's forced withdrawal.

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And there's an urgency to how they work.

They are just a few kilometres from enemy lines and their position is exposed and in the line of fire.

Quickly and with sharp focus the arms of the drone are unfurled.

As they hide in a slit trench in the undergrowth the propellers fire up and it's away buzzing like a giant insect across the steely grey skies.

The drone pilot - who's known by his call sign Playboy - is scouting out where best to attack the Russian army.

His partner, known as Badger, helps keeps watch for any signs of movement on the horizon.

On the screen of his controller Playboy can see the blocky images of Russian soldiers.

He marks the coordinates, the position he's viewing in real time is now a target.

"First of all, we are working with artillery," he says.

"We'll find the targets find the enemies with the drones, with the different UAVs and get the information to the artillery and they work them."

Without these troops Ukraine would be firing blind

But these Ukrainian soldiers are taking huge risks.

While they can see the enemy the Russians also have drones and they can be easily spotted.

As they work the sound of incoming fire arcs overhead slicing the air with a deadly whine and they take cover.

It misses but it highlights the threat they face every day.

This is dangerous work but without this eye in the sky Ukraine's artillery crews would be firing blind.

Further back from the frontline, troops from a volunteer platoon called Karlson, which relies on donations, load up a grad rocket system with ammunition.

Foreign fighter says cost to Ukraine is high

Among them are foreign recruits.

Shannon, who's a former soldier in the New Zealand military, says he joined them because he doesn't like "bullies".

He says the unit is having successes but the cost to Ukraine is high.

"It's going good," he says.

"We're pushing them back and they've fallen back and unfortunately, they're destroying everything as they go.

"They target a lot of schools and buildings that have no military value other than to disrupt the way of life. It's pretty sad".

No time to hang around as winter sets in

With winter on its way the fight for Kherson has become more desperate in recent weeks.

Ukraine is eager to take advantage of its momentum and Russia's newly announced retreat.

The artillery team soon receives the coordinates from the drone reconnaissance unit and they are on their way to the launch site.

The firing position has been primed and it doesn't take long to line up the target.

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There's no time to hang around. It all needs to be done at speed.

As they fire, shouts of "glory to Ukraine" fill the air and several grad rockets are soon scorching across the sky on their way to the target.

Images captured by the drone team show the impact - explosions send shockwaves through the Russian trenches they spotted earlier.

It's these kinds of artillery barrages that are forcing the Russians to withdraw.

Playboy says in this area Ukraine now has the advantage.

"This is the war between artillery most of all - who has the best one? That one has advantage in the battlefield.

"We are moving forward and even where we have less power on the battlefield we are trying to get the results."

But even before the smoke clears from the rocket launch the Ukrainian artillery team are making their escape.

They are vulnerable now to a rapid counter strike.

This fight here is a clash of nerve and firepower and for the moment on this perilous frontier Ukraine is winning.