It may have been his 15th time in a helicopter, but the experience was still a fresh one for Mr Stephen Wiltshire yesterday.

"I have not been to Singapore before, so there are many buildings, new and old, that I will have to remember," said the celebrated 40-year-old architectural artist, who will today begin drawing a 4m by 1m panorama of the city from memory.

Following a land tour on Monday, the Briton's aerial view will help him prepare for the drawing.

The hour-long Super Puma helicopter ride, which was sponsored by the Republic of Singapore Air Force, took off from Sembawang Air Base. Mr Wiltshire and his sister Annette, 42, were then flown to the Marina Bay area, which they circled several times.

"I think Singapore is great, lots of high-rise modern buildings, skyscrapers and avenues! Lots to remember," he said after the trip, picking out Marina Bay Sands as his favourite building.

Mr Wiltshire, who was diagnosed with autism when he was three years old, has created panoramas of cities like Hong Kong.

He will be at the main atrium of Paragon from today until Sunday completing the drawing of Singapore's cityscape, which was commissioned by Singapore Press Holdings to celebrate its 30th anniversary in an event called See The Big Picture.

The finished work of art will be presented to President Tony Tan Keng Yam in September as a gift to Singapore for the nation's 50th birthday next year.

Watch videos of Mr Wiltshire sketching other cities on his YouTube channel.