The band 1610.6-1613.8 MHz is used by the radio astronomy (RA) community in order to study the spectral line of the Hydroxyl (OH) radical transitions. This radical is considered to be one of the most important lines for the observation of physical phenomena associated with the formation of protostars and the initial stages of star formation. The current ITU recommendation to protect this RA ban...

After a short introduction, an overview about the Global Navigation Satellite Systems (GNSS) GPS, GLONASS and Galileo is given. For each system, a status report is presented and then the three main positioning algorithms: Single Point Positioning, Differential Pseudorange and Carrier Phase Positioning are described. In the Summary, the systems are compared and and outlook is given.

The Real Time Kinematic (RTK) method is widely used in the land surveying. Whereas RTK has advantage of practical use, positioning accuracy depends mostly on baseline length due to atmospheric errors. In general, measurements are made by using GPS and GLONASS satellite systems. For this reason, performance technique adversely affected under restricted geometry conditions such as urban canyons. ...

In the present paper, the nonlinear equations describing all the nonsingular pencils of metrics of constant Riemannian curvature are derived and the integrability of these nonlinear equations by the method of inverse scattering problem is proved. These results were announced in our previous paper [1]. For the flat pencils of metrics the corresponding statements and proofs were presented in the ...