Intellectual Property (IP) rights (December 2003/Lange):
Both the Meteorological and Geodetic communities have simultaneously discovered the same semi-analytic computing method for solving large Normal Equation systems. In Geodesy, it is known as the Helmert-Wolf blocking method (Wolf, 1978) and employed in Europe e.g. by the Bernese GPS software (Brockmann, 1997). In Meteorology, this method was first reported in connection with post-calibrating upper-air windfinding devices (Lange, 1975) and generally for post-calibrating all observing systems (Lange, 1986).
Any real-time recursive use of this Helmert-Wolf blocking method transforms it into a Fast Kalman Filter (FKF) of Lange (1989). Any reliable (stable) use of FKF requires that the error covariance matrix of all estimated parameters is known (Lange, 1982). Three types of different applications of the FKF have since been successfully patented worldwide. These applications are: ordinary (PCT/FI90/00122), Extended (PCT/FI93/00192) and Adaptive (PCT/FI96/00621) Kalman Filtering.
These IP rights of the FKF are currently under the ownership of the following European companies:
Anti Lange Corp. (USA, Japan and some European countries)
Blue Sky Enterprises Ltd. (Spain and Switzerland)
Calfat Ltd. (most countries of the world and some European)
FKF-Finland Oy (Finland)
Moiree Ltd. (Estonia).