The Ulsan project would be located 60km east of Ulsan City in the southeast of the country in the Sea of Japan.
It will be installed across three phases, GIG said, with the first 400MW phase due in 2022.
The deployment of the floating lidar — the first in South Korea — will last for two years to collect data about wind speeds and direction to inform the project design, GIG said.
GIG has also signed a Memorandum of Understanding with Korean fund manager Energy Infra Asset Management to help develop the project.
GIG said the Ulsan project forms part of the government's plan to source 20% of the country's electricity from renewable sources by 2030.
"With its access to steel, ships, offshore plant expertise and port logistics, Ulsan City is perfectly positioned," said GIG associate director, Woojin Choi.
"Our ambition is for the Ulsan project to contribute to local economic development, revitalise local industries, create jobs and support the South Korean government's renewable '3020' plan."
GIG — previously called the Green Investment Bank when owned by the UK government — helped fund the construction of several offshore wind projects in the UK.
According to Windpower Intelligence, the data division of Windpower Monthly, South Korea has 37MW of installed offshore wind capacity, including the 30MW Tamra project completed in 2016.