Acknowledgements

The authors express their deep appreciation to the following University of Iowa personnel for their substantial contributions in implementing the Visible Imaging System: K. L. Ackerson, R. L. Brechwald, S. M. Cash, T. L. Clausen, L. M. Henry, E. T. Howard, E. Kruse, H. R. Peltz, P. S. Reilly, and R. M. Wenman. In addition important support and services were also provided by J. Hrastar, J. Galloway, K. O. Sizemore, M. H. Acuna, V. B. Patel, and D. Crosby of the NASA/Goddard Space Flight Center. This research was supported in part at The University of Iowa by the National Aeronautics and Space Administration under Contract NAS5-30316.