Published online by Cambridge University Press: 12 April 2016
The NRL High Resolution Telescope and Spectrograph (HRTS) consists of a telescope, stigmatic UV spectrograph, UV broadband spectroheliograph and Hα film and video cameras. An image of the Sun is focussed onto the slit jaws of the spectrograph by a 30 cm Cassegrain telescope with a spatial resolution of 1". The stigmatic UV spectrograph employs a tandem-Wadsworth mount and photographically records spectra along the 1000" (1 solar radius) slit with a resolution of 50 mÅ in the 1170–1710 Å wavelength region. Images of the slit jaws in a tunable 100 Å bandpass are produced on film by the UV spectroheliograph which uses a reversed tandem-Wadsworth mount. The slit jaws are also viewed through an Hα filter by video and film cameras. To date, the HRTS instrument has flown on four rocket flights and is being prepared for flight on Spacelab-2.