An Intensified Storage Vidicon Camera for Finding and Guiding at the Telescope

This chapter discusses an intensified storage vidicon camera for finding and guiding at the telescope. It is a great convenience at astronomical telescopes to use a television viewing system which can see faint objects directly. Integrations of several seconds are made to obtain an image of adequate signal to noise ratio and then the target is read out. The image is stored in a scan converter and is continuously read out to give a normal television video signal for display on standard monitors. In some systems very deep images are obtained by digitally adding several integrations to improve the signal to noise ratio. The intensifiers are 25 mm electrostatically focused diodes. The vidicon is protected against deflection circuit failure by sampling the voltage developed across the current sense resistors in series with the deflection coils. This signal is amplified and used to trigger retriggerable one-shots upon retrace.