rtk-rs/gnss-rtk

Precise Point Positioning (PPP) and Real Time Kinematics (RTK) in Rust

gnss-rtk's Issues

Support RTK (differential positioning)

RTK is currently not supported and needs to be introduced.
We support full PPP including surveying without apriori, which is much more complex.

RTK

RTK is a ground-ground differential technique that is very commonly used and is easy to deploy.

Stabilize Phase Range exploitation

Phase Range Navigation is selected with Method::PPP and is currently 50 % completed.
The basis is there, we need to conclude all calculations, which should provide PPP for at least "ideal scenarios" (good conditions and performant receivers).

Phase range navigation is complex due to the possible perturbations that may happen.
We need good analysis, smart decision making, yet try to maintain things simple and efficient.

Replace our Kalman Filter implementation by Nyx::KF

Nyx-Space proposes an advanced and thorough Kalman Filter implementation.
Considering we already use Nyx intensively (and depend on it), it is pointless to rewrite the same functions twice.

The Nyx framework is also more advanced and will most likely perform better. Most notably, with the possibility to upgrade to an Extended KF at the apropriate time.

Current implementation

Our implementation is basic and is the simple KF filter obtained by adding two terms to the LSQ filter.
Our implentation does work and will not change, it will eventually be replaced when this topic is solved.

Vice Versa

On the other hand, we do have a very good LSQ filter implementation.
If it makes sense, it could be cool to introduce LSQ in Nyx along its KF definitions, and remove it from here.

LSQ is sort of a cheap KF, it requires 2 to 4x less operations (roughty), and converges slower.
It does not have the notion of "model" therefore cannot be used to confirm a prediction and improve theoretical models

Improve CI/CD

Testing navigation under CI / CD

The solver is currently not fully tested under CI / CD. The main equation and functions are not.
Some preliminary work have been introduced to correct that, but it requires more work.

@ChristopherRabotin, could you tell me a little more about Kani that you use in Hifitime ?
Is that an open solution ?
The problem in GNSS-RTK being (once we have a solution to provide input data) that it has several options.
For example, let say you want to validate the PPP solver, you need to at least verify it works with all major options: 3 navigation methods and 3 navigation modes, that's 9 combination. Could Kani help in building effecient and smart tests ?