Yesterday, as crowds headed to watch the Super Bowl, DigitalGlobe’s WorldView-3 satellite collected an astonishing view of San Francisco:
East is up in this image. The Marin Headlands are in the lower left, San Francisco stretches across the bottom, and Berkeley and Oakland are along the top.
We don’t often see pictures like this one. The problem is haze: as a camera in space looks toward the horizon, it sees more water vapor, smog, and other stuff in the atmosphere that obscures the Earth. But our friends at DigitalGlobe built WorldView-3 with a sensor suite called CAVIS, which lets it quantify and subtract haze – making atmospheric effects virtually invisible. Only WorldView-3 can see so clearly at this angle.
The satellite is about 17° above the horizon from San Francisco, and it is looking about 60° away from the point directly under it. At first I thought there was a typo, because 17° off horizontal should be 73° off vertical, not 61°. But while sketching it out, I realized I was assuming the ground is flat. WorldView-3 is way out over the Pacific – more than 1300 km or 800 miles to the west, and over that distance the Earth curves by about 12°!
Pan and zoom to see landmarks and details:
The Golden Gate Bridge connects the hills of the Marin Headlands with San Francisco.
Downtown San Francisco: The Bay Bridge in the upper left, the Transamerica Pyramid in the left side of the cluster of skyscrapers, and the dome of City Hall in the bottom right. The Mapbox SF office is in SOMA, between City Hall and the curve in the I-80 highway.
The Upper San Leandro Reservoir, in the hills of the East Bay, is surrounded by oak, sequoia, and eucalyptus trees. Its banks are dry – despite the green of the hills, the area is still in long-term drought.
The old Bay Bridge, next to the new span, caught in the process of being disassembled. Pan up (east) to see the Port of Oakland, or down (west) to see Alcatraz.