Nearly nine months ago I was fascinated by the possibility of high precision position measurements using the GNSS real time kinematics technique.
However I struggled with the missing driver support for my ultra-low-cost-receiver. I took this as an opportunity to improve my C language coding skills and created my first GitHub repository by forking Tim Everetts rtklibexplorer repository.
As a rule of thumb, the distance to next reference station should be less than 10km for this kind of measurement. Professional Equipment is available on the market, but not at an reasonable price – the idea of a battery backed mobile reference station was born.
Meanwhile I was able to realize this by using a BananaPI M64, a U-Blox M8-T GNSS receiver, a Tallysman TW2712 antenna and a USB LTE Modem. By using a 4000mAh LiPo battery I was able to reach runtimes of more than 90 minutes.
On the bench this setup works well, but poking on the command line is not very convenient for an application to be used in the field.
Owing to my persistence, I was looking for a comfortable solution which could be used from a cell phone or tablet via a 5 GHz Wifi – resulting in a fork of Bill Zimmerman’s RaspAP. I added interfaces for AVM Fritz!Box VPN connectivity, Modem Manager including short messages and various RTK-related GNSS features, including the capability to perform measuerements according to VwVLV in UTM-coordinates mapped to BWTA2017
I added interfaces for AVM Fritz!Box VPN connectivity, Modem Manager including short messages and various RTK-related GNSS features, including the capability to take UTM coordinate measurements according to VwVLV using the NTv2 grid corrections of BWTA2017. Therefore, in addition to the technical details, I had to learn how to code in PHP, Python, Javascript and how to use Plotly for data visualization.
I would like to take this opportunity to thank my wife Jennifer and my son Sebastian from the bottom of my heart for their continuous love, support and forbearance.
