Near-infrared camera for solar research: a photometric application

摘要

Abstract: We report here the main characteristics of a near IRcamera devoted to astrophysical solar research, whichhas been developed by the Instituto de Astrofisica deCanarias (IAC). The system is now being used forphotometric and spectroscopic applications, and it willalso be used for spectropolarimetry in the near future.The first application is described below in detail. TheIACs IR camera is based on a Rockwell 256 $MUL 256HgCdTe NICMOS3 array, sensitive from 1 to 2.5 microns.The necessary cooling system is a LN2- cryostat,designed and built by IR labs under out requirements.The main electronics are the standard VME- based, FPGAprogrammable MCE-3 system, also developed by IR labs.We have implemented different readout schemes toimprove sped, reduce noise and avoid seeing effects,taking into account each specific application. Data aretransferred via fiber optics to a control unit, whichre-send them to the main data acquisition system.Several acquisition modes to select the best imageshave been implemented, and a real- time data processingis available, the entire camera has been characterizedand calibrated, and the main radiometric parametersgiven. Preliminary test in spectroscopic observationshave been made in the German Towers at the Observatoriodel Teide in Tenerife, Spain, and a series ofphotometric measurements performed in the Swedish SolarTelescope, at the Observatorio del Roque de losMuchachos in La Palma, Spain. As examples, somescientific results are also presented. !4