SimpleRTK2B+headeing Coordinates of the midpoints of the two antennas

Q&A forumCategory: QuestionsSimpleRTK2B+headeing Coordinates of the midpoints of the two antennas
kodama asked 3 weeks ago

I’m now trying to build a human navigation system using simpleRTK2B+heading.
So I am wondering how to get the position coordinates of the two antennas of this heading kit. The position coordinates can be understood as each NAV-PVT message, but if you want to output both (primary and secondary) messages from one USB port, how should you set it? I want the midpoint of both position coordinates to be the actual position coordinate.
I would appreciate any advice.
Thank you.

Ardusimple Staff replied 3 weeks ago

Hi kodama,
The default configuration should already provide you with relative position measurements between antennas. If you changed it, you can set it again following the steps in this page: https://www.ardusimple.com/configuration-files/

You will also find more details about which message to use in the hookup guide: https://www.ardusimple.com/simplertk2heading-hookup-guide/

About your question of receiving the middle point of both antennas, unfortunately this is not possible, you will have to do the math externally.

2 Answers
kodama answered 3 weeks ago

Dear Ardusimple stuff
Thank you for your answer.
I haven’t changed the default settings, but is the latitude/longitude value of the NAV-PVT obtained from the RTK2BLite board the position coordinates of the antenna connected to RTL2BLite?
I want to send the position coordinate (NAV-PVT?) message on the other board (RTK2B) via RTK2BLite. Is there a way?
I would appreciate any good advice.
Thank you.

Ardusimple Staff replied 3 weeks ago

yes the srtk2blite outputs the position of the antenna connected to srtk2blite.

i’m not sure i understand why would you like to send the position of one device to the other device.

kodama replied 3 weeks ago

I’m thinking of using the Raspberry Pi to perform the process of calculating the midpoint from the positions of the two antennas, but I thought that it would be good if the input USB ports could be combined into one.

Ardusimple Staff replied 3 weeks ago

the POWER+GPS outputs in one message the position of both antennas (UBX-NAV-RELPOSNED). From there you can extract the middle point.

kodama answered 3 weeks ago

I have one more question. The relative distance between the two antennas is shown in N and E in UBX-NAV-RELPOSNED. Is there a way to get the units for this number as degrees instead of meters?
I thought that it is possible to calculate the midpoint of two antennas by using this value.
Thank you.

Ardusimple Staff replied 3 weeks ago

unfortunately not that we know, you will have to do the conversion externally.

clive1 replied 3 weeks ago

I think that’s covered by middle/high school geometry / trigonometry ..

kodama replied 3 weeks ago

As you say, we will handle this with an external calculation.
Thank you.