I have long been an advocate of signal diversity as a solution to many of the ills that plague the GPS user, especially outdated user equipment. The best equipment, if it were available today, would be the PHGPST or Perfect Handheld GPS Transceiver. I cannot count the thousands of letters and emails from warfighters, first responders, and civil users who immediately see the value of software-defined receivers and want to know where to purchase the PHGPST. For now, some early GPS software-defined user equipment does exist, but to reach the goal of the PHGPST receiver manufacturers must first be able to accurately and reliably simulate/generate all the diverse PNT (position, navigation and timing) signals available, which include some signals not ordinarily categorized as PNT signals today. Certainly not an easy task; however, there is hope. Recently I heard about a small GNSS/INS simulation company that may be paving the way to the PHGPST — CAST Navigation in Tewksbury, Massachusetts.