BEIJING — A low-flying drone glides at full speed over gravel scattered on a swath of desert near Hami in the far western Chinese region of Xinjiang. The desolate expanse betrays little sign of human habitation. But the drone ascends and, gradually, the stones cohere into shapes that clearly show human intervention, and the ghost of Mao Zedong.
Bare earth cutting through the gravel forms huge Chinese characters that read “Long live Chairman Mao,” “Serve the people,” “Seize the minute, seize the hour,” “Learn from struggles” and “Surmount every difficulty to win victory.” These Maoist slogans now form the core of a new film, “Big Characters,” by the independent director Ju Anqi, who is based in Beijing.
The slogans were constructed in 1968, two years after the onset of the decade-long Cultural Revolution, as navigation aids by members of a military aviation school. Although they have attracted sporadic attention over the years, because they are visible in satellite images, they went largely unknown to the public.
Mr. Ju said he had long wanted to make a film about the Cultural Revolution. “This part of history has always been affecting us, distorting us and reshaping us,” he said in an interview.
But he also wanted to weave in scenes from leftist movements around the world from that time, he said, as a way of exploring the emptiness many feel once the dust of revolutionary ardor settles. In the forgotten stones, he said he saw the “collapse of utopia.” While the gravel proclaims stirring slogans when viewed from on high, it looks like little more than ruins to people on the ground.
“The big characters construct a utopian miracle, stirring people’s passions,” Mr. Ju said. “But when I arrived on the scene and looked at the gravel that forms the big characters, I only felt a deep sorrow.”
In the film, Mr. Ju intersperses scenes of crowds chanting “Long live Chairman Mao,” the May 1968 demonstrations in Paris, President Lyndon B. Johnson delivering a speech on the war in Vietnam and Soviet tanks crushing the Prague Spring with his drone footage of the stones. At the premiere in Beijing on Friday evening, he said, he plans to split the film and present it on two screens side by side, with one showing the international unrest and the other the gravel.
Mr. Ju first heard about the navigational markings in 2002 from a friend in Hami, but he thought his friend was joking. It was not until late 2014, when he happened to be using Google Earth to research another film project, that he looked for the marks himself.
“I was shocked by how clearly visible they were,” he said.
After learning they were built in 1968, a year that had long intrigued him for the political stirrings around the world, he decided to make a film, he said. It was also around 1968 that his parents, two “sent-down youths,” left their homes in the eastern province of Jiangsu in response to Mao’s call to urban students to learn from farmers and to cure themselves of bourgeois thinking. Mr. Ju was born in Urumqi, the capital of Xinjiang, in 1975.
He set out with eight crew members and two drones from Beijing to Hami last June and spent eight days filming the big characters. “The marks are little known even to local residents,” Mr. Ju said.
Ji Chenye, 80, who designed the markings, came to Hami in 1966, when the military was planning to set up the Eighth People’s Liberation Army Aviation School. The school opened in 1967, and Mr. Ji served as the navigation director of a regiment that trained at Luotuojuan, a military airport southeast of Hami.
In 1968, Mr. Ji decided to create five navigational signals around the airport, to guide pilots trying to make their way over the featureless desert. He said he chose the five slogans not just for political reasons, but because he believed they would fortify the pilots’ resolve.
“The characters pushed them to work harder, flying into the sky and defending our motherland,” Mr. Ji said in a telephone interview from Tonghua, in the northeastern province of Jilin, where he was principal of a school for public security officials from 1982 until his retirement.
Mr. Ji said he first marked out the characters on the desert floor. Then several dozen soldiers and trainees spent nearly half a year removing stones so the bare earth would reveal the characters. Each character occupies about 50 square meters of land, or more than 500 square feet, he said. The five slogans together occupy an area of around 75,000 square meters, or 18 acres.
Mr. Ji, clearly proud of his mammoth calligraphy, said he had never heard of any other navigational markings like these anywhere else in China.
“I feel these are part of our country’s cultural heritage,” he said. “Even in the world, I believe they are the best.”
An earlier version of this article misspelled the name of an airport. It is Luotuojuan, not Luotuojian.
Correction: March 18, 2016