Random conversation in Matt McGrath’s office a couple years ago after reading Nick Chrisman’s book we all knew

TRANSIT (also known as NAVSAT), the first satellite navigation system, used by the US Navy, was successfully tested

• TRANSIT (also known as NAVSAT), the first satellite navigation system, used by the US Navy, was successfully tested

• Used a constellation of five satellites
• It could provide a navigational fix (200 meter accuracy) approximately once per hour
• Led by F.T. McClure (Johns Hopkins APL)
• Doppler shift, encoded signal
• Used for ballistic missile submarine positioning
• Funded by ARPA, retired in 1996

AT&T designed the Dataphone, the first commercial modem, specifically for converting digital computer data to analog signals for transmission across its long distance network

• AT&T designed the Dataphone, the first commercial modem, specifically for converting digital computer data to analog signals for transmission across its long distance network

• The development of equalization techniques and bandwidth-conserving modulation systems improved transmission efficiency in national and global systems