Winemaking isn’t exactly high-tech. You take some grapes, add a little sugar and yeast-then let nature take its course. But now National Aeronautics and Space Administration (NASA) researchers are helping bring space-age technology to the ancient art of making wine in a partnership with Robert Mondavi Winery in California’s Napa Valley. The scientists at NASA’s Ames Research Center in Mountain View, Calif., are collaborating with Mondavi to explore the use of digital remote sensing data in vineyard operations. The remote sensing data help winegrowers harvest their grapes with more precision-yielding higher quality wine.

There are many different kinds of remote sensing instruments, some of which pick up information invisible to the naked eye. The class of remote sensing instruments known as “multi-spectral imagers” measure radiation in the visible and near-infrared parts of the electromagnetic spectrum. For the Mondavi project, NASA acquired multi-spectral imagery from a digital camera flown on an airplane at 14,000 feet over Napa Valley. The data were then processed to create a special “vegetation index” emphasizing information on the amount of chlorophyll in the plants, which can be used to make estimates of plant health and maturity. “The vegetation index is calculated using relatively narrow spectral bands centered in regions that are perfect for looking at vegetation,” says Lee Johnson, senior remote sensing scientist at NASA Ames.

The Mondavi growers study the vegetation index maps to find out which parts of the field have similar plant density or vigor. These discrete areas can be sampled on the ground for maturity and harvested separately. Traditionally, Mondavi harvested an entire vineyard block at once. But the conventional method results in some grapes being overripe when harvested, and others underripe. Subdivision of the vineyard based on remote sensing characterization allowed Mondavi to harvest segments of its fields at different times to coincide better with optimal ripeness.

The early results of this work are promising. Mondavi has produced wine from experimental fields of chardonnay and pinot noir grapes, and Daniel Bosch, Mondavi Vineyard technical manager, reports that there are clear improvements over traditional harvesting methods. “There were portions of the vineyard that were previously not used for our higher quality wine. But now the wine from some of those same blocks will be used in our reserve program. That’s a big step for us,” says Bosch.

“What we’re doing is separating the wheat from the chaff,” explains Bosch. “So although some of the wine from the remote sensing experiment was better, some of it was not. This forced us to look more closely at those weaker areas. And this is leading us to a much better understanding of what’s going on in the vineyard.”

As a result of its work with NASA, Mondavi plans to incorporate the remote sensing technology into operations on a regular basis next year. And the operation may go to an even higher-tech level in the next harvest. The first satellite to yield data specifically for agricultural use was scheduled for launch later this year by a company called Space Imaging, based in Thornton, Colo. Assuming there are no glitches in the satellite’s operation, Mondavi plans to buy processed images from Space Imaging for future growing seasons. In the end, of course, how widely these methods are adopted in the winemaking industry will be-like everything else in winemaking-a matter of taste.