NEO-F9P

Data sheet

https://content.u-blox.com/sites/default/files/documents/NEO-F9P-15B_DataSheet_UBX-22021920.pdf?utm_content=UBX-22021920

Integration Manual

https://content.u-blox.com/sites/default/files/documents/NEO-F9P_IntegrationManual_UBX-22028362.pdf

Interface spec

https://content.u-blox.com/sites/default/files/documents/u-blox-F9-HPG-L1L5-1.40_InterfaceDescription_UBX-23006991.pdf?utm_content=UBX-23006991

ZED-20P

Data sheet

https://content.u-blox.com/sites/default/files/documents/ZED-X20P-00B_DataSheet_UBXDOC-963802114-12690.pdf

Integration Manual

https://content.u-blox.com/sites/default/files/documents/ZED-X20P_IntegrationManual_UBXDOC-963802114-12901.pdf?utm_content=UBXDOC-963802114-12901

Interface spec

https://content.u-blox.com/sites/default/files/documents/u-blox-20-HPG-2.00_InterfaceDescription_UBXDOC-304424225-19888.pdf?utm_content=UBXDOC-304424225-19888

Real time Kinematics

ESA Article

https://gssc.esa.int/navipedia/index.php?title=Real_Time_Kinematics

RTCM 3.0

Overview

https://www.geopp.de/pdf/gppigs06_rtcm_f.pdf

Cheat sheet

https://www.use-snip.com/kb/knowledge-base/an-rtcm-message-cheat-sheet/