NASA, ESA Calibrate Satellites on Bolivia's 10,000-Sq-Km Salar de Uyuni as Flooding Preserves Its Flatness
Updated
Updated · spacedaily.com · Aug 6
NASA, ESA Calibrate Satellites on Bolivia's 10,000-Sq-Km Salar de Uyuni as Flooding Preserves Its Flatness
1 articles · Updated · spacedaily.com · Aug 6
Summary
Under clear, dry conditions, Bolivia’s Salar de Uyuni serves as a calibration target for NASA and ESA satellites because its 10,000-square-kilometre salt crust is extraordinarily flat and highly reflective.
ESA says elevation varies by less than 1 metre across the salar, while a 2002 GPS survey mapped a 45-by-54-kilometre section to about 2.2-centimetre accuracy and found only 77 centimetres of relief.
That smoothness is maintained by seasonal flooding: rain dissolves salt from high spots, then evaporation redeposits it in low spots, effectively resurfacing the plain each summer.
The same mirror effect that attracts tourists can ruin measurements—ICESat passes over flooded salt in 2005 produced elevation errors of about 1 metre after ripples saturated the laser return.
The site’s scientific value may face longer-term pressure from lithium extraction beneath the crust, where brine pumping could interfere with the near-surface salt layer that annual flooding keeps level.