So you want a Stratum 1 NTP server...
Using the Sure Electronics GPS evaluation board for NTP
Adafruit Ultimate GPS GNSS with USB - 99 channel w/10 Hz updates : ID 4279 : $29.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Millisecond accurate Chrony NTP with a USB GPS for $12 USD - Austin's Nerdy Things
GPS-721U-MRTU | ICP DAS USA Inc - Data Acquisition
GPS-DO expansion board GPS input PPS and 10MHz output port USB PC | eBay
Time Server
Gps Glonass Galileo Bds Pps Uav Ugv Usb Ttl Topgnss L1 L2 L5 Top982 New Rtk High Precision Gnss Module + Antenna Full Frequency - Gps Receiver & Antenna - AliExpress
GitHub - ddrown/usb-gps: Stratum 1 NTP setup using USB to transfer GPS PPS info
GPS to RS-232/USB interface diagram. | Download Scientific Diagram
Comint India | Products - Fullview
Frontiers | Time Synchronization for Wireless Sensors Using Low-Cost GPS Module and Arduino
VK-162 G-Mouse - Remote Mount USB - External GPS Navigation Dongle - Supports Stratux, Raspberry Pi, - YouTube
z050 USB GPS Dongle with PPS
Wholesale BASEUS Share Together PPS 120W Fast Charging Cord Multi-port 3 USB + Type-C Car Charger Adapter with 1.5m Cable from China | TVC-Mall.com
GPS-DO expansion board GPS input PPS and 10MHz output port USB PC | eBay
USB GPS Module – ODROID
Adding PPS to a cheap USB GPS stick | Brendan's Radio Blog
Microsecond accurate NTP with a Raspberry Pi and PPS GPS - Austin's Nerdy Things
Raspberry Pi GPS Module USB Port – Kuongshun Electronic Shop
Adding PPS to a cheap USB GPS stick | Brendan's Radio Blog
USRP Open SDR B210 Metal Shell 705X Material, ΠGPS 10MHz USB PPS DC 6-12V | eBay
GPS receiver supports PPS through standard USB interface
