Design, Development and Performance of Cryocooler Drive Electronics for Sea Surface Temperature Monitor Payload

Knowledge of sea surface temperature along with ocean colour information provides a vital information to identify and locate the potential fisheries zone (PFZ). ISRO has developed one Sea Surface Temperature Monitor (SSTM) payload for oceanographic studies. SSTM images in Thermal Infrared (TIR) region and the imaging detector needs to be operated at cryo temperature
$(\approx 50\mathrm{K})$
for higher responsivity. To achieve desired performance, detector is integrated in a motor-based cryocooler. This paper presents the details of ISRO's first indigenously developed Drive Electronics for in-orbit TIR cryocooler. Temperature of 50K with stability
$\pm 45_\text{mK}$
is achieved. Electronics design paves way to development for future cryocooler stability requirement <10mK with higher efficiency.