Several years ago Skytraq introduced NavSpark mini, a tiny (17x17mm) GPS module, that sold for $6. I got one and wrote a post explaining how to get started with the GPS module using GNSS viewer program.
The company contacted me again today, as they’ve now launched an even smaller module Skytraq PX1122R measuring just 16x12mm, supporting GPS, Galileo, GLONASS, and Beidou signals, as well as Real-time Kinematic (RTK) relative positioning technique that allows for 1-3cm positioning accuracy.
Skytraq PX1122R RTK GNSS module key features & specifications:
- Chipset – SkyTraq PX100 Phoenix GNSS chipset
- Supported GNSS standards & bands – GPS L1/L2C, Galileo E1/E5b, Beidou B1I/B2I, GLONASS L1/L2, QZSS L1/L2C
- Integrated RTK with 1cm + 1ppm RTK accuracy in seconds (under 10 seconds)
- Up to 10Hz quad-GNSS RTK update rate
- Base or rover mode configurable
- Serial Interface – 3V LVTTL level
- 24x castellated holes with UART, RF input, 1PPS, Reset, 3.3V, GND (most pins not used)
- Input Voltage – 3.3V DC +/10%
- Current Consumption – 50mA
- Dimensions – 16 x 12.2 mm
- Weight – 1.7 grams
- Temperature Range – 40°C ~ +85°C
Centimeter-level precision can be used for agriculture, machine control guidance (UAV), survey and GIS data collection, structure, and deformation monitoring. RTK applications require a base and a rover. The base can either be a third-party RTK base station service, or a PX1122R module configured accordingly.
PX1122R module is also compatible with PPP services such as OPUS, AUSPOS, CSR-PPP, etc.. by submitting a dual-frequency RINEX log file converted from carrier phase raw measurement log file of a single PX1122R.
To help getting started with the module, the company also offers a breakout board (pictured above), as well as PX1122R-EVB “PX1122R Multi-Band Quad-GNSS RTK Evaluation Board” with USB, UART, and Bluetooth SPP (Serial Port Profile) interface. The Bluetooth SPP interface allows rover NTRIP client connection to remote non-line-of-sight RTK base via a smartphone connected to the Internet and running a mobile app such as ArcPad or Esri Collector.
Skytraq PX1122R mass-production will start/has started this month, and while RTK positioning looks promising, RTK module and boards do come at a much higher price with PX1122R going for $99, while the breakout board goes for $125, and the evaluation board for $150. You’ll find all three on Navpark Store. You’ll find more details including a getting started guide, a datasheet, GNSS viewer program, and firmware on the respective product pages on the store.
The video above shows RTK initialization in GNSS viewer program.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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It’s impressive to think that this device is able to detect distance variations smaller than its own size and possibly than its antenna!
This is what an equivalent RTK module looked in 2015:
https://www.cnx-software.com/wp-content/uploads/2020/05/RTK-module-2015.jpg
They told me the “RTK receiver has size and price shrunk by 20 fold.”
Just to note that Ublox M8P with similar specs was released early 2017 and smaller size, so this size for RTK is not a new thing. The newer ublox F9P is at same price range and boast even better specs.
Really nice for agricultural drones, but a base station near is required and at fixed position
I wonder why RTK modules are so expensive. Are these using cutting edge techniques? Isn’t it a matter of applying signal corrections?
Low volumes?
No NavIC support?
• is there any other good multi-band/-frequency GNSS module (to be used with RTK, though not necessarily RTK done by the module itself) apart from this one and the ublox F9P? Both the latter and the PX1122R here seem rather expensive, which kinda sux. It seems that currently, the high prices are mostly due to lack of competition out there.
• how does the PX1122R compares to the ublox F9P? The comparative table on the product page in the NavSpark store presents the PX1122R as being identical in specs except for slightly faster possible refresh rates, but iirc the F9P has integrated USB for example. Anyways, the even more important difference would be the matter of features, support and configurability, ideally with open source software. Is there any data/review about how the SkyTraq module fares compared to the ublox in that respect?