> As an aside, I have been unable to get my hands on any modern multi-frequency GPS receivers. If someone has a link to one that I can buy with a credit card, I would love it!
Try SwiftNav or Tersus. I have not used either of them so I can't comment on the quality, but $1-2k for an RTK setup is pretty great. They are both more 'startup' than traditional suppliers.
uBlox F9 looks good but isn't quite available yet. They have a solid line of single frequency receivers so I'm looking forward to seeing pricing.
I have briefly tested some Unicorecomm from China, and they work well, but they miss your online store requirement, and the documentation is nonexistent.
I'd suggest Yocto is the de facto standard for this kind of embedded device. It's a bit complex behind the scenes but general building and updating packages is fairly straightforward.
Bringing up the edison is very easy. The bootloader supports DFU, so you can simply connect USB, reset, and flash the system images.
If you're coming at it from a higher level, it has a node.js and ssh services running by default, so it's easy to start tinkering.
The Pandora [1] is a few years old at this point. I had one for a short while and wasn't too impressed. There will be an update called the Pyra [2] coming later this year.
As mentioned in the sibling, media codec is the nominal case. They are included in the SOC, not something specific to this project.
Being ARM Cortex processors, they are 32 bit. Allocate them a chunk of RAM, upload a program and set them running. TI has a driver infrastructure and sample gstreamer CODECs.
They are referring to integer ambiguity resolution, which is the final step in getting a dual-frequency differential GPS position down to centimeter accuracy.
This [1] is a good explanation. It does require a GPS receiver capable of carrier phase tracking, which your cell phone isn't capable of. The cheapest I've seen is this uBlox [2].
Do you have any references for the ground-satellite abilities for 5G? I couldn't turn up anything on Google.
Locata [1] has been in the high-end space for a while. I had heard of a lower-end approach too, though the name escapes me, and they were only getting ~50cm.
Edit: The other one I was thinking of was decaWave [2], they claim 20cm in 2 dimensions.
I think this is a little misleading. The IEEE paper is about a reducing the computational effort for a filtering technique (Contemplative Real-Time) developed by one of the authors, which seems to be published here [1].
The original paper in compares the CRT approach to a more traditional Extended Kalman Filter (EKF) approach. The EKF is very efficient but it does trade of some accuracy, because it requires a linear approximation of the system to be used. Both the CRT and EKF are used to blend or fuse inertial measurement data with GPS.
To achieve the claimed centimeter-level accuracy requires a local (within ~20 miles) base station and a data connection to the base station to achieve the levels of accuracy being discussed. Depending on the quality of the GPS receiver there will be a few seconds up to 10s of minutes convergence period for the GPS filters to initialise.
The results presented in [1] show that using a moderately expensive (dual frequency, code tracking) GPS can approach (not exceed) the accuracy of a high-end GPS (dual frequency, code and carrier phase).
In summary, this is a interesting incremental improvement, not a huge breakthrough that's going to bring centimeter accuracy to cell-phone GPS tracking.
Isn't the car calling their service center / 911 one of the major selling points of the service?
The root problem is that they were able to flash an ECU with custom code. From there they are 'trusted' on the vehicle network and can trigger or emulate any other component.
Requiring the firmware image to be signed, or not accepting a bootload from the physical interface that's connected to the internet would be a more comprehensive solution.
I don't have any inside knowledge of the Deere system, but I'd be very surprised if it was. My guess is that most of the Deere stuff comes NavCom. That is certainly the case for their GPS system.
> "NavCom's involvement with Deere & Company began with Deere's GreenStar precision farming system in 1994 and has expanded into many areas of Deere's product activities. The commitment by the most senior Deere management to information systems leadership motivated the NavCom shareholder-employees to join with Deere & Company,"
These systems have no sensors beyond GPS and IMU, and typically only control the steering.
Typically they are following a predefined path, not even having the concept of where the end of the row is, relying on the operator for turning and avoiding any hazards. The most advanced functionality is Machine Sync [1], which is still only using the GPS to synchronize the machines.
Just because the functionality is basic, doesn't mean it's not useful. We are quickly coming to the point where these systems will be installed on every machine. The reduction in fatigue and other benefits are profound.
Another point to note is that getting to this point was a marathon, not a sprint. These systems have been around in one form or another for more that 20 years. Acceptance came in large part with the generation change of the owners. It will be interesting to see if the rollout of self-driving cars follows a similar trend.
There are a bunch of factors. There are both correlated and uncorrelated errors that you need to correct. The main source of correlated error is ionospheric distortion, which will affect the two units mostly equally. At the low end (cheap cell phone GPS receivers), the measurement errors unique to each device will tend to dominate.
If you wanted to experiment, there's no need to do it online. If you log the output of the two receivers you can align the timestamps and try different ways of post-processing.
RTK GPS is quite common for levelling applications. It's closer to 25mm in the vertical when a local (~10km) base station is used. Lasers are used but have line-of-sight and atmospheric distortion issues.
Try SwiftNav or Tersus. I have not used either of them so I can't comment on the quality, but $1-2k for an RTK setup is pretty great. They are both more 'startup' than traditional suppliers.
uBlox F9 looks good but isn't quite available yet. They have a solid line of single frequency receivers so I'm looking forward to seeing pricing.
I have briefly tested some Unicorecomm from China, and they work well, but they miss your online store requirement, and the documentation is nonexistent.