Tim,

Yes a more common name would be a Radial.
Although, in most instances a Ground Radial
is often connected to a Ground Rod.

The Counterpoise is usually required to lay
directly below the Wire Antenna Element.

What 'i' have called a Buried Copper Wire
{Flexible} Ground Rod without a Hard Rod :
Ends up being Four # 8 AWG Bare Copper
Wires {= 0 AWG} for 6.25 Feet that tapers
into Two # 8 AWG {= 4 AWG} Bare Copper
Wires {= 0 AWG} for another 6.25 Feet that
tapers into One # 8 AWG Bare Copper Wires
{= 8 AWG} for 12.5 Feet that tapers for a
Total Length of 25 Feet.

X
|_________________________ 25Ft.
|_____________ 12.5Ft.
|_______ 6.25Ft.
|_______ 6.25Ft.

IMHO - This Four Wire Buried Copper Wire
{Flexible} Ground Rod Set-Up can be as
effective as a Solid Ground Rod that is 8 Feet
Long and driven vertically 8 Feet deep in to
the Ground Soil. In some areas it may be more
effect.

The [KEY] to the whole set-up is "If" you
are doing all the work of digging trenches
for an in-the-ground Sprinkler System.
Then 'Why Not' also place a Buried Copper
Wire {Flexible} Ground Rod Set-Up in the
trenches and make use of the already pre-
expended labor ! ;-}
Note - The Deeper the Trenches the better
12"-18" is better than 6"-8".

Ground Conductivity :
There is a 'key' Advantage to this Buried
Copper Wire {Flexible} Ground Rod Set-Up
in that the Sprinkler System generally helps
to maintain a moist under-soil around the
Ground Rod {Wires} and the overall Ground
Conductivity is very effective 24&7 )

in an imperfect world . . .
this is just another grounding option
cause after all - iane ~ RHF