UBlox GPS-RTK Breakout

This ZED-F9P-based GNSS HAT provides centimeter-level accuracy. It offers features such as multi-band RTK with quick convergence times, a high update rate, support for moving base RTK mode, simultaneous reception of four GNSS systems, support for augment positioning systems, accurate & quick positioning with minimal drifting, and exceptional anti-spoofing & anti-jamming capabilities.

• Supports Raspberry Pi series boards, Rock SBC series boards, Jetson Nano, Banana Pi, and more with a standard 40PIN GPIO extension header...
• Fast convergence times, centimeter-level accuracy, and high update rates for multi-band RTK
  
• Supports Moving base RTK mode, enabling centimeter-level accuracy and precise terminal navigation.
  
• Supports simultaneous receiving of 4 GNSS constellations (GPS, BeiDou, Galileo, and GLONASS) while yet using very little power.
  
• Enhance systems that provide service location positionings, such as SBAS, QZSS, IMES, and D-GPS
  
• Support for A-GNSS (Assisted GNSS), which speeds up initial positioning and increases acquisition sensitivity
  
• Features strong anti-spoofing and anti-jamming capabilities, -167dBm navigational sensitivity, and supports geo-fencing.
  
• Supports U-Center, a simple module configuration method
  
• Rechargeable batteries are supported via the onboard battery holder, which protects ephemeris data and hot starts.
  
  Specification:
  

  GNSS features
  GNSS	BeiDou, Galileo, GLONASS, GPS / QZSS
  Number of concurrent GNSS	4
  GNSS platform	Concurrent GNSS
  GNSS bands	B1I, B2I, E1B/C, E5b, L1C/A, L1OF, L2C, L2OF
  Oscillators	TCXO
  Interfaces
  UART	2
  USB	1
  I2C	1
  SPI	1
  Electrical data
  Maximum supply [V]	3.6
  Minimum supply [V]	2.7
  Environmental data, quality & reliability
  Maximum temperature [°C]	85
  Minimum temperature [°C]	-40
  Features
  Active antenna / LNA control	✓
  Active antenna / LNA supply	✓
  Additional SAW	✓
  Antenna open circuit detection pin	✓
  Antenna short circuit detect/protect pin	✓
  Base station with survey-in	✓
  Carrier phase output	✓
  Data logging	✓
  Jamming detection	✓
  Programmable flash memory	✓
  RTC crystal	✓
  RTK rover	✓
  Secure boot	✓
  Timepulse output	✓
  General features
  Antennas	Pin (active) for external antenna

Resources:

Software GitHub: Getting Started Guide 
Hardware GitHub: Hardware Design files like Schematic, 3D File, Step File, etc.