We quantify the relative impact of the number of satellite altimeters on the U. S. Navy's operational ocean data assimilation system. Satellite altimeter data are assimilated into the NRL Layered Ocean Model (NLOM) to produce dynamically interpolated sea surface height (SSH) fields. These are used with optimally interpolated sea surface temperature (SST) fields by the Modular Data Assimilation System (MODAS) to produce three-dimensional subsurface temperature and salinity fields. We evaluate parameters of mixed layer depth, sonic layer depth, and below layer gradient estimated from these predictions relative to those estimated from in situ ocean profile observations. Predictions are made using a varying number of satellite altimeters from zero to the three currently operating systems, Jason, GFO, and ENVISAT. We quantify the relative improvement of parameters predicted using the GFO versus the Jason satellites and the relative improvement of each additional satellite.