The SOLIS project continues toward initial operational capability in 2001. Work on the mount is underway at the GONG prototype site a few kilometers from the Tucson offices. The next milestone for the mount is to run the motors and track the Sun. Progress on the highest priority instrument, the Vector SpectroMagnetograph (VSM), suffered a setback when it became clear that the custom CCD cameras would be delivered much later than expected. The project, with the help of its outside Science Advisory Group, considered a number of options for dealing with this delay. The present strategy is to arrange with the vendor for a staged delivery of increasingly more capable CCD and camera systems to enable the project to perform its early camera integration testing without falling very far behind the original schedule. Other aspects of the VSM are progressing well. The primary mirror is finished, and the secondary is expected to be done by the end of July. Mechanical parts are either finished or under construction. Electronic and software testing of several of these mechanisms are in progress. A commercial data acquisition board capable of handling the "fire hose" of data from the VSM is being prepared for use. The software algorithms for reducing VSM data continue to be developed and tested.
The software group has completed the first phase of the Observation Control System (the means of scheduling and managing observations) and the Instrument Control System (the software that actually controls the instruments to acquire observations). On the calibration front, a version of the Kuhn-Lin flat-field algorithm optimized for use with spectra has been developed and tested using Integrated Sunlight Spectrometer (ISS) data. The results are very good. The ISS CCD had become contaminated as a result of a seal failure. The vendor, however, fixed the seal and cleaned the CCD successfully. The lowest priority instrument is the Full Disk Patrol (FDP). The FDP preliminary mechanical design was reviewed and upgraded to a nearly final design. A minor change in one of the three parallel optical paths was made as a result. All of the off-the-shelf optics for the FDP are in hand, and orders for custom optics are underway.
Two REU summer students, Jessica Erickson and Jose Ceja, have been working with Jack Harvey and Harrison Jones, respectively, to calibrate the existing synoptic data sets with primary and secondary alter-nate sources of similar data. This is in preparation for cross-calibration of the existing instruments with SOLIS before the former are replaced. A third REU student, Rebecca Pifer, is working with Christoph Keller in testing and optimizing the polarization modulator packages for the VSM.