An improved 4 - 18 micron array camera system has been developed at NASA Goddard Space Flight Center for astronomical photometry, using an Aerojet ElectroSystems Co. 16 x 16 Si:Bi (Bismuth doped Silicon) accumulation mode charge injection device (AMCID) with 256 active pixels, obtained from NASA/Ames Research Center as part of a new scientific collaboration between the Ames and Goddard infrared array research groups. An astronomical observing program using this device has been carried out as a collaboration between NASA Goddard Space Flight Center (Infrared and Radio Astronomy Branch and Micro Electronics Branch) , the Harvard-Smithsonian Center for Astrophysics, and Steward Observatory of the University of Arizona, and NASA Ames Research Center. The 16 x 16 device had sufficiently good sensitivity, uniformity and noise characteristics to be used for successful observations at the Steward Observatory Mt. Lemmon 60 and 61-inch telescopes in May 1983, and at the NASA Infrared Telescope Facility (IRTF) at Mauna Kea in August 1983. Initial results indicate that this detector has sensitivity and noise characteristics comparable to other devices from the same generation of Aerojet arrays. Si:Bi AMCID detector array characteristics and performance have been discussed in general by Parry (1980) , McCreight and Goebel (1981) , and by Parry (1983). For a discussion of earlier array camera work at Goddard see Arens et al. (1981), Lamb et al. (1983) , and references therein.