25 Years of Altimeter Developments at ALCATEL Alenia Space

T he first preliminary stud ies on the definition of radar altimeter for Sea Surface Height (SSH) measurements started in the 80 ' s in Alcatel Alenia Space under CNES and ESA contracts. A t that time CNES contemp lated the possib il ity of flying an ocean topography mission on its own . It was eventually decided to fly a NASA /CNES jo in t mission , Topex/Po seidon ( T/ P) , embarking a US radar altimeter and a French experimental altimeter Poseidon . In parallel ESA decided to fly an altimeter on the European Remo te Sensing Satelli te (ERS-1) and in itiated the preliminary stud ies. Thu s A lcatel A lenia Space is invo lved in altimeters design and manufacturing for more than 25 years. A lcatel A lenia Space develops state of the art altimeters for ocean, ice and land application s wh ich are presented in th is paper.