Zhang helped build the software widely-used to create 3D maps based on ultra high-definition satellite images, called Socet GXP.

Now Zhang wants to pair this hyper-sophisticated satellite mapping software with cheap drones and GPUs to slash the cost of generating detailed 3D maps that can help the world’s poorest use their resources more productively.

“There are hundreds of millions of people like my brother,” says Zhang, speaking to more than 150 people who crowded into a small room to hear him speak Tuesday. “He has only six years of education, but it’s not because he’s dumb.”

Zhang holds five degrees, including a PhD from the University of Wisconsin. His brother, however, came of age during the Cultural Revolution, the anti-intellectual ferment that crushed the dreams of some of China’s best and brightest. Amidst the tumult, he only got six years of schooling.

Now Zhang’s brother is dying of cancer. He couldn’t afford to see a doctor who might have diagnosed his cancer in time to save his life. “I feel guilty about this,” Zhang says, tearing up for a moment during a conversation after his presentation. “I wish I could have helped him more.”

Zhang’s goal now: to help the world’s 100 million poorest people – many of whom are farmers – make the most of their meager resources. To do that, Zhang has to slash the cost of creating detailed maps.

These maps can do more than just help farmers, however. Reducing the use of fertilizers and pesticides can limit runoff from farms, while helping produce more food for a world whose population continues to grow.

Drones can play a big role here because they can provide images much more cheaply than satellites. So can GPUs, which can turn still images gathered by drones into point clouds 10 times faster than CPUs alone.

Such maps can help farmers cut reduce the cost of the fertilizer they use by more than 25%. It can also help them spot deadly pests that can wipe out their crops – a serious challenge for farmers who rely on the naked eye to detect pests.