Throughout the design process of the hardware and software for the Keck Telescopes, the possibility of implementing remote observing, particularly from Waimea, the location of the Keck headquarters in Hawaii, was kept in mind (see Figure 9). The instruments, their motors, and the detectors are operated through workstations that are located in the control room of the Keck Telescope dome. It is not necessary during normal night-time operation to go out to the instrument on the telescope to make any adjustments or changes.
We have concerned ourselves exclusively with enabling remote observing on the Keck II telescope with the Low Resolution Imaging Spectrograph  (LRIS; see Figure 10). This is the primary optical instrument at the observatory, and the only instrument capable of obtaining direct images at optical wavelengths. It is used on Keck II almost every night of the year. Although our efforts have concentrated on remote observing with LRIS, we note that all of the instrument interfaces have been engineered in a similar fashion, so our results could be easily extended to other instruments on Keck I or II.
Figure 11 illustrates the organization of the telescope and instrument control hardware at the Keck Observatory. The majority of the complications associated with remote control of the instrument have stemmed from security issues and the desire to not impact normal (i.e., non-remote) observations with the telescope. For example, concerns about the effect of a such a high-speed network, especially in various failure modes, on other computer and network systems at Keck, as we approached this project with our initial inexperience, forced us to isolate remote operations more thoroughly by duplicating the instrument control computer. This machine provides boot information for the instrument motor and CCD detector VME crates, as well as the interface between the user and the control systems. The remote portion of the observing system, the workstation at Caltech, is integrated into the system merely as a remote display, using the X Window System protocols. Although this is perhaps not the most efficient method of providing remote operations, it is certainly the most straightforward, especially in a relatively new and frequently changing facility such as Keck.