ExtendedSemianalyticalKalmanFilter (Orekit Tutorials 12.1-SNAPSHOT API)

java.lang.Object
- org.orekit.tutorials.estimation.ExtendedSemianalyticalKalmanFilter

```
public class ExtendedSemianalyticalKalmanFilter
extends Object
```
Tutorial to present the Extended Semi-analytical Kalman Filter.
Because the DSST orbit propagator uses large step size to perform the numerical integration of the equations of motion for the mean equinoctial elements (e.g., half-day for GEO satellites), itvssical Extended Kalman Filter orbit determination. The classical Extended Kalman Filter algorithm needs to re-initialize the orbital state at each observation epoch. However, the time difference between two observations is usually much smaller than the DSST step size. In order to take advantage of the DSST theory within a recursive filter orbit determination, Orekit implements the Extended Semi-analytical Kalman Filter.
This tutorial presents the functional validation test performed in the second reference below. It corresponds to a 5-days orbit determination of Lageos 2 satellites. Lageos' positions are used as observations during the estimation process.

Author:

Bryan Cazabonne

See Also:

"Folcik Z., Orbit Determination Using Modern Filters/Smoothers and Continuous Thrust Modeling, Master of Science Thesis, Department of Aeronautics and Astronautics, MIT, June, 2008.", "Cazabonne B., Bayard J., Journot M., and Cefola P. J., A Semi-analytical Approach for Orbit Determination based on Extended Kalman Filter, AAS Paper 21-614, AAS/AIAA Astrodynamics Specialist Conference, Big Sky, August 2021."

- Nested Class Summary
  
  Nested Classes
  Modifier and Type Class Description
  
  static class ExtendedSemianalyticalKalmanFilter.Observer
  Observer for Kalman estimation.
- Constructor Summary
  
  Constructors
  Constructor Description
  
  ExtendedSemianalyticalKalmanFilter()
- Method Summary
  
  All Methods Static Methods Concrete Methods
  Modifier and Type Method Description
  
  static void main(String[] args)
  Main method.
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ExtendedSemianalyticalKalmanFilter
```
public ExtendedSemianalyticalKalmanFilter()
```
- Method Detail
  - main
```
public static void main(String[] args)
                 throws URISyntaxException,
                        IOException
```
    Main method.
    
    Parameters:
    
    args - nothing is needed
    
    Throws:
    
    IOException - if observations file cannot be read properly
    
    URISyntaxException - if URI syntax of SP3 file is wrong