Since 1994, the International GNSS Service (IGS) has provided precise GPS orbit products to the scientific community with increased precision and timeliness. Many national geodetic agencies and GPS users interested in geodetic positioning have adopted the IGS precise orbits to achieve centimeter level accuracy and ensure long-term reference frame stability. Relative positioning approaches that ...

Since 1994 the International GPS Service (IGS) has provided precise GPS orbit products to the scientific community with increased precision and timeliness. Many national geodetic agencies and GPS users interested in geodetic positioning have adopted the IGS precise orbits to achieve centimeter level accuracy and ensure long-term reference frame stability. Relative positioning approach that requ...

This work is an example of application of nonlinear programming to a problem of three-dimensional trajectory optimization for multistage launch vehicles for geostationary orbit missions. The main objective is to minimize fuel consumption or equivalently to maximize the payload. The launch vehicle considered here, Europa-II, consists of 5 thrust phases and 2 coast phases. Major parameters of the...

The first three ionization potentials of americium are calculated using ab initio spin-orbit configuration interaction techniques. These results are favorably compared with experimental and theoretical work. The lowest two ionization potentials are accurately determined using wavefunctions constructed as simple single and double substitutions from a self-consistent field reference configuration...

Spin–orbit coupling is a manifestation of special relativity. In the reference frame of a moving electron, electric fields transform into magnetic fields, which interact with the electron spin and lift the degeneracy of spin-up and spin-down states. In solid-state systems, the resulting spin–orbit fields are referred to as Dresselhaus and Rashba fields, depending on whether the electric fields ...

Precise orbit control is one of the crucial ingredients for stable operation of the SLS storage ring. The orbits are taken by the digital BPM system which allows beam position measurements to the sub-micron level at sampling rates of up to 4 kHz at 72 locations in the ring. Orbits are corrected with respect to a user defined reference by applying SVD techniques and a direct response matrix inve...

An on-orbit flat-field monitoring program was initiated for the MAMA detectors with the goals of comparing the pre-launch flat-field characteristics with those observed on-orbit, measuring the stability of the FUVand NUV-flats, and creating updates to the reference flats. We found that the NUV-MAMA flat-field images at nominal (1024x1024) resolution are well corrected with pre-launch flats. Tha...