Reflectometry, a microwave remote‐sensing technique to extract geophysical data from scattered satellite transmissions, was first demonstrated using Global Navigation Satellite System (GNSS) reflections. Recently, reflectometry has been extended to the reutilization of digital communication satellite signals for Earth remote sensing, now referred to as “signals of opportunity.” This expands the application of reflectometry to most microwave bands that penetrate the Earth's atmosphere. GNSS+R 2012 provided an opportunity for engineers and Earth scientists to assess the state of the art, demonstrate new applications, and discuss potential missions.