US shoots down Chinese balloon: What exactly surveillance balloons are used for

China said Tuesday it will “resolutely safeguard its legitimate rights and interests” over the shooting down of a suspected Chinese spy balloon by the United States, as relations between the two countries deteriorate further. The balloon prompted U.S. Secretary of State Antony Blinken to cancel a highly-anticipated visit to Beijing this week that had offered slight hopes for an improvement in relations. The whole episode has led to questions about what exactly surveillance balloons are used for. Balloon Pic. By Chase Doak - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=128439300. Statue of liberty Pic. By osunpokeh - Own work.This file was derived from:Human outline.svgF-22 3 view USAF.jpgw:File:Christ and Liberty.svghttps://www.flickr.com/photos/usairforce/7414511440, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=128418970. Balloon flight path photo By M.Bitton - Own workPalumbo, Daniele (3 February 2023). China balloon: Could it have been blown off course as Beijing claims?. BBC News. Retrieved on 4 February 2023.Petras, George (3 February 2023). US tracked suspected Chinese spy balloon for 5 days before shooting it down over the Atlantic. USA TODAY. Retrieved on 6 February 2023., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=128404128