U-band observations with the LSST have yet to be fully optimized in cadence. The straw man survey design is a simple coverage of the medium-deep-fast survey. Here we argue that deep coverage of the four deep drilling fields (XMM-LSS, ECDFS, ELAIS-S1 and COSMOS) has a much higher scientific return, given that these are also the target of the Southern Hemisphere's Square Kilometer Array Pathfinder, the MeerKAT specifically, deep radio observations.
@article{arxiv.1812.03144,
title = {Large Synoptic Survey Telescope White Paper; The Case for Matching U-band on Deep Drilling Fields},
author = {B. W. Holwerda and A. Baker and S. Blyth and S. Kannappan and D. Obreschkow and S. Ravindranath and E. Elson and M. Vaccari and S. Crawford and M. Bershady and N. Hathi and N. Maddox and Russ Taylor and Matt Jarvis and Joanna Bridge},
journal= {arXiv preprint arXiv:1812.03144},
year = {2019}
}