The Gemini Multi-conjugate adaptive optics System (GeMS) at the Gemini South telescope in Cerro Pachón is the first sodium-based multi-Laser Guide Star (LGS) adaptive optics system. It uses five LGSs and two deformable mirrors to measure and compensate for atmospheric distortions. The GeMS project started in 1999, and saw first light in 2011. It is now in regular operation, producing images close to the diffraction limit in the near infrared, with uniform quality over a field of view of two square arcminutes. The present paper (I) is the first one in a two-paper review of GeMS. It describes the system, explains why and how it was built, discusses the design choices and trade-offs, and presents the main issues encountered during the course of the project. Finally, we briefly present the results of the system first light.

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Cataloged from PDF version of article.An efficient and accurate hybrid method, based on\ud the combination of the method of moments (MoM) with a special\ud Green’s function in the space domain is presented to analyze antennas\ud and array elements conformal to electrically large material\ud coated circular cylinders. The efficiency and accuracy of the\ud method depend strongly on the computation of the Green’s function,\ud which is the kernel of the integral equation that is solved via\ud MoM for the unknown equivalent currents representing only the\ud antenna elements. Three types of space-domain Green’s function\ud representations are used, each accurate and computationally efficient\ud in a given region of space. Consequently, a computationally\ud optimized analysis tool for conformal microstrip antennas is obtained.\ud Input impedance of various microstrip antennas and mutual\ud coupling between two identical antennas are calculated and\ud compared with published results to assess the accuracy of this hybrid\ud method

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