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QUB-ASL / bzzz

Quadcopter with ESP32 and RaspberryPi
MIT License
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RFC: Market research for GNSS modules and antennas #164

Closed alphaville closed 7 months ago

alphaville commented 7 months ago

Market research for GNSS modules/antennas

I'm looking for high-precision GNSS modules. These ArduSimple simpleRTK2Blite Multiband GNSS Boards seems to be good candidates. They are priced at around £214 on Mouser.

If we get a couple of modules, my understanding is that we can operate them in a base-rover configuration.

Just before I order this, can we check that (i) it's appropriate for our application, (ii) it's not too large and we're happy with the size, (iii) we've done a proper market research.

Comparison

Criteria to take into account:

  1. GNSS module
  2. Base-rover capability
  3. Size
  4. Weight
  5. Price
  6. Availability of documentation
  7. Interfaces (UART/USB is needed)
  8. Real-time kinematics (RTK)
  9. Fast update rate
  10. Must be in stock!
Product Comments Price
ArduSimple STARTKIT-LITE-L1L2-HS Comes with antenna and XBee carrier (not XBee); GNSS module: ZED-F9P; dimensions: 50x30x10mm; weight: 8g; datasheet; general info; connector: SMA £289
SparkFun GPS-16481 GPS-RTK-SMA Breakout with ZED-F9P; product details; interfaces: I2C, UART, USB; dimensions: 43.5 mm x 43.2 mm; weight: 23.4 g; further product details; RTK: yes; Base-rover: yes; antenna: not included; connector: SMA; further documentation/tutorials; RTK update rate 20Hz; can be powered at 5V, but works at 3.3V; ⚠️ we need two such modules for RTK, otherwise the accuracy will be low £233
RTK2B-MICRO-F9P-L1L2SMATH-00 Very small size simpleRTK2B Micro with SMA connector; made by ArduSimple; product details; update rate 1Hz; £212
SparkFun GNSS Combo Breakout - ZED-F9P, NEO-D9S Breakout board with Z-F9P GNSS module and a NEO-D9S that offers L-band corrections. They say it obviates the need for a base station (but I'm not sure whether this is trully equally accurate); RTK rate: 20Hz; dimensions: 43.2mm x 63.5mm; ⚠️ back-order £373
Sparkfun Mosaic X5** RTK Accuracy: 0.6 cm horizontally / 1.0 cm vertically; 100Hz update rate; four UARTs; requires an active multiband antenna (are we happy with this?); µSD Card Slot (up to 32GB w/ FAT32 file system); Latency: < 10ms; Only one left in stock (I checked with the Uni and they said we can purchase this); dimensions: 2" x 2.5" (2.5 x 6.4 cm); weight: 40g; max current: 150 mA (is this too much?!); additional info; ⚠️ I guess two modules are needed for RTK ⚠️ ⚠️ requires specific L1/L2/L5 antenna which is heavy and not available £610
ZED-FP9 + Dead reckoning This module is similar to SparkFun GPS-16481 but performs dead-reckoning; hookup guide; in stock; 1cm accuracy with RTK; Built-In Accelerometer and Gyroscope; Max Navigation Rate: Up to 30Hz; receives L1C/A and L2C bands; GPS, GLONASS, Galileo and BeiDou; SMA connector £242

** This is our runner-up; please review carefully @jamie-54 @pdavid747 @Runway27 @Yuanbwcx @Minanchi

Antennas

Requirements:

Product Comments Price
Flexible antenna with SMA connector £3.7
ANT-GNRM-L125A-3 £85
MEA-GNSS-LTE 698 MHz - 2.69 GHz; GLONASS + GPS; size: 48 mm ; 39 mm; cable: 1m; weight: 40g; gain: 1-2 dBi £23
ALPHA 4A GPS Antenna, Siretta 26 +/- 2dB peak gain; lead: 1m; £19
Puck Omnidirectional GPS Antenna Linx ANT-GPS-SH2-SMA Puck Omnidirectional GPS Antenna with SMA Connector, GPS; datasheet £42
ublox antenna SMA connector; dimensions: 82 mm x 60 mm x 22.5 mm; weight (incl. cable): 173g (a bit heavy); supports BEIDOU, Galileo, GLONASS, GNSS, GPS; gain: 2-3 dBi; 5m cable £48
lighter ublox antenna Active GPS antenna with integrated low-noise amplifier; SMA connector; 5m cable £28
Helical Antenna GNSS Multi-Band L1/L2/L5 Helical Antenna - SMA (BT-T009); weight: 22g; GPS, GLONASS, Galileo, and BeiDou constellations; connector: SMA-J; cable length: 60cm; datasheet £95
ANN-MB ublox active antenna; wide range; weight: 104g £27.77
Lightweight ublox antenna High performance active GPS antenna; datasheet; weight: 42g; in stock £27.25

Literature review

It is useful to see what people in the literature has used for navigation applications.

Compass

The above modules don't have a compass, but (i) we'll have two IMUs on board and both have a magnetometer, (ii) the anemometer most likely has a compass - the Bosch IMU should be quite good; (iii) worst case, we can get a cheap compass like this one and position it away from the other electronics, (iv) we can do sensor fusion.

[^1]: ZED-F9P Data Sheet, p. 8

alphaville commented 7 months ago

Base-rover configuration seems to be quite straightforward as shown in this video

alphaville commented 7 months ago

There's also this SparkFun breakout with the same module, but seems to be smaller (43.5 mm x 43.2 mm ). It's just slightly more expensive (£233). Its weight is 23.4 g. See also https://www.mouser.co.uk/new/sparkfun/sparkfun-gps-rtk-sma-breakout/.

alphaville commented 7 months ago

There's also this little thing from ArduSimple.

pdavid747 commented 7 months ago

https://www.mouser.co.uk/ProductDetail/SparkFun/GPS-16481?qs=vmHwEFxEFR8xw%2FiWbXmISw%3D%3D

I think this one would be best value for money as its refresh rate is only 5hz below the more expensive version, as well as that its well documented and we can use it with a usb port.

alphaville commented 7 months ago

https://www.mouser.co.uk/ProductDetail/SparkFun/GPS-16481?qs=vmHwEFxEFR8xw%2FiWbXmISw%3D%3D

I think this one would be best value for money as its refresh rate is only 5hz below the more expensive version, as well as that its well documented and we can use it with a usb port.

This uses RTK to give an update rate of 20Hz. We'd have to buy two of these (one for the quadcopter and one for the base station), but this is within our budget.

image

Which is the more expensive version you're referring to?

pdavid747 commented 7 months ago

SparkFun GNSS Combo Breakout - ZED-F9P, NEO-D9S

this one

pdavid747 commented 7 months ago

would we have to buy two of these also?

pdavid747 commented 7 months ago

if not it might be beneficial to go with that one as it will work out cheaper

alphaville commented 7 months ago

would we have to buy two of these also?

In the product description they say "With a clear view of the sky, specifically to the South, this combo breakout will deliver centimeter-level accuracy positioning without needing separate RTK or NTRIP corrections!" and "With this board, you will know where your (or any object's) X, Y, and Z location is better than an inch without needing a separate correction source!"

I haven't found a comparison between the two modules, though. It would be also good to know whether it works reliable around our corner of the Earth.

Just a thought: if we get two SparkFun GPS-16481 we have two potential advantages: (i) we can get a NEO module later and connect it to the ZED-F9P, (ii) we'll have redundancy: if one module gets fried, most likely we'll still get decent accuracy and be able to fly (e.g., using SSR corrections).

pdavid747 commented 7 months ago

it illustrates the it is operational around the us and Europe, but its quite vague. I suppose if we found a video of someone using it in the uk we could find out that way

pdavid747 commented 7 months ago

https://www.youtube.com/watch?v=TSkIvtaVZc0

this video is quite useful

alphaville commented 7 months ago

https://www.youtube.com/watch?v=TSkIvtaVZc0

this video is quite useful

Good find! Indeed, Mosaic X5 looks great, but it's at £610. However, it provides update rates at 100Hz and sub-cm errors.

alphaville commented 7 months ago

Some additional information we need to be aware of:

This is what SparkFun says about RTK:

[...] an RTK receiver takes in an RTCM correction stream and then calculates your location with 1cm accuracy in real time. [...] You’ll also need a source of RTCM correction data. This usually comes from an internet connection or a long distance radio capable of approximately 500 bytes per second. LoRa and LTE-CAT M1 are superb choices for this backhaul.

More precisely we can get RTCM Corrections:

  1. From Skylark but there's a monthly subscription of $50
  2. By making our own NTRIP server that will provide RTCM corrections (documentation here); we could actually do that, but we'd need to get a second GNSS module and an antenna, but we can buy a cheaper GNSS module.
  3. From the EUREF Permanent GNSS Network and we're lucky that there's a station in Belfast somewhere at the harbour

In anycase, unless we need to fly far away from Belfast (>10km from harbour), we won't need to make our own NTRIP server.

So, which one do we buy?

Sparkfun Mosaic X5 still seems like a good idea, but without RTCM corrections the accuracy will be poor (around ±1.5m). However, we can get correction data from the Belfast station. The only downside is that an Internet connection is required, but I've already ordered a 4G-enabled WiFi router, so we'll have a connection anywhere we go.

@pdavid747, @jamie-54, @Runway27, @Yuanbwcx, @Minanchi thoughts?

alphaville commented 7 months ago

Update: The Belfast NTRIP station has been down since April 2023 (link). The closest active RTK is in Ballymena.

jamie-54 commented 7 months ago

Hi all the Sparkfun Mosaic X5 seems like a pretty good option, and so does the Sparkfun Combo if it work straight out of the box. It says it should in Europe which is a bit vague so trying to see if there's any review for UK. Either way both options seem to be cheapest from unmanned tech Sparkfun Mosaic X5 = £610 Sparkfun Combo = £300