GPS modules that are most likely to work with a LIDAR mapping sensor

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I need advice on the GPS modules that are most likely to work with a LIDAR mapping sensor. I want to determine the location of data points captured by a LIDAR sensor that I am using to create a 3D map of bamboo plantations. The lidar sensor being used is called Airy from Robosense, which captures 856,320 data points per second using 940 nm laser wavelength with a 360 rotation at 600 rpm (10 Hz). The Airy device supports GPS, PTP and gPTP to be sent by a GPS Module using an interface cable inbuilt with a 2.54-4P connector. The LIDAR sensor creates the map and builds the location coordinates associated to the data points. What I need help is to determine a suitable GPS module, ideally one that is stand alone (with inbuilt battery), with an inbuilt antenna or one that allows an easy connection to external antenna, and that provides ideally less than 3 mt precision.

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Hi Carlos,

Welcome to the forum!!

Sounds like a great application!

Do you have a link to the resources section where a GPS can be added?

These specs seem pretty easy to check off, Re: the battery though, how long would you like the charge to last?

Liam

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Thanks Liam,
AiryRobosenseUserManual20250109100322_54878.pdf (3.9 MB)

I would prefer the battery to last 8 hours or more. I have uploaded the Airy LIDAR user manual.
Carlos

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Hi Liam, just to clarify the GPS module could alternatively have a connection to an external battery or have a replaceable battery. I am OK as long as there is an easy way to power it.
Carlos

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A quick look over the data sheet/guide and from what I read it seems that the GPS can be either TTL or RS232 (via a setting on the webpage).

Standard baud etc 9600,8,N,1
Uses the PPS, so an easy break out of that.
Some timing needs to be meet as well i.e. PPS 20-200ms and the GPRMC data must be completed within 500ms of the sync pulse.
Most GPS Units allow the turning on/off of different messages, so if you turn of all but the GPRMC (if needed), then that should be well out within 500ms;

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Hi Michael, thanks for looking into this and checking the info. Could you please recommend a couple of GPS modules that you think would be suitable? I have never worked with GPS modules and don’t know how to select one versus another.

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I assume you have the sensor and connection cables ?
The guide said that in the interface you could choose if it was UART or RS232, can you have a look at your user interface for the GPS and confirm that ?

If it takes either, then really any GPS that has a “pulse per second”, “tx” gps output and ground should work.
So then its down to form factor, external antenna and power needs.
I am a fan of the little Neo 6 GPS, but in this case it wont suite as the PPS is not broken out (cleanly), But if you want cheap, you could make it work.
In that past I have use the Garmin OEM Bare wire GPS units, the look like a puck, run RS232 signals, has the pulse per second, and come with a few meters of cable.

Have a browse around the different GPS modules on cores websites and if you think one looks good to you (i.e. your needs) paste a link to it back here and we can review and ensure it should work.
It will also give you an idea of cost v functions.

Im happy to have a look of the specs, but I find it a little hard to recommend things I have not used before; so if you focus on what your needs are we can confirm the tech specs will be ok prior to a purchase.

That said, I am more then happy for others to recommend!

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The LIDAR sensor and the connection cable are scheduled to arrive this Friday or early next week.
The manual says that GPS_REC interface of Airy LiDAR adopts the RS232 electrical level protocol.
The objective of the project is to manage bamboo plantations of a giant species that has culms (shoots/poles) that are 30 mt tall, 200mm in diameter and located in average 400mm between each other. I need to be able to capture the GPS location of the culms so the precision of the GPS should be ideally below 1mt, but I am aware this is very difficult, so I am targeting a precision of less than 3mt. As I have never used GPS modules, I can’t be sure how the precision affects the location within a map.
The specification of Garmin GPS 18x PC says that the precision is <15 mt. I am not sure if this is a significant factor, but it seems to lack the precision I think I need. I found the Garmin GPS at Complete avionics for AUD $75, which is within my budget, but if I would prefer one with better precision.
I will start to look for GPS modules similar to Garmin’s one but with more precision. If anyone can help me with other possible GPS modules to check I would really appreciate it.
Thanks Michael for your help so far!!

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I found one that has great precision called RTD Precision Agricultural receiver at the link below, could you please check if this seems to comply with the requirements?

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The specs are very brief, but include:
Protocol Support NMEA 0183 v2.3 and V4.x
GGA, GLL, GSA, GSV, RMC, VTG, TXT (selectable)
RS232 level output
Baud rate: 9600 (default), 4800, 38400,115200

There is no mention of a PPS signal but the standard connector is 4 pin so it is possible. You would probably need to contact the local distributor directly to find out whether or not PPS was supported, and if it meets the requirement.

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I have emailed the manufacturer of the RTD Precision GPS receiver asking them to confirm if their equipment matches the requirements, hopefully it will. If there are any other suggestions please send them

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