NPR: Amateurs Identify U.S. Spy Satellite Behind President Trump’s Tweet.

“Amateur satellite trackers say they believe an image tweeted by President Trump on Friday came from one of America’s most advanced spy satellites.

The image almost certainly came from a satellite known as USA 224, according to Marco Langbroek, a satellite-tracker based in the Netherlands. The satellite was launched by the National Reconnaissance Office in 2011. Almost everything about it remains highly classified, but Langbroek says that based on its size and orbit, most observers believe USA 224 is one of America’s multibillion-dollar KH-11 reconnaissance satellites.
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Melissa Hanham, a satellite imagery expert and deputy director of the Open Nuclear Network in Vienna, Austria […] says she is amazed a satellite can provide such clear imagery. Spy satellites must peer down through Earth’s atmosphere, which is a bit like trying to look at objects in the bottom of a swimming pool. They also must snap their pictures while whizzing across the sky. Both effects can blur the fine details in images.

“I’m now scratching my head and curious about how they account for the effects of the atmosphere and motion of the objects,” she says.

And she says she thinks she’s not alone. Others will be trying to use the image to learn more about how USA 224 works. “I imagine adversaries are going to take a look at this image and reverse-engineer it to figure out how the sensor itself works and what kind of post-production techniques they’re using,” she says.

Hanham questions whether Trump’s tweet zinging the Iranians was worth the information this image provides to other nations, but she adds: “It’s his decision as the president.””