Generation of a consistent absolute phase-center correction model for GPS receiver and satellite antennas   总被引：26，自引：16，他引：10  

Ralf Schmid  Peter Steigenberger  Gerd Gendt  Maorong Ge  Markus Rothacher 《Journal of Geodesy》2007,81(12):781-798

The development and numerical values of the new absolute phase-center correction model for GPS receiver and satellite antennas, as adopted by the International GNSS (global navigation satellite systems) Service, are presented. Fixing absolute receiver antenna phase-center corrections to robot-based calibrations, the GeoForschungsZentrum Potsdam (GFZ) and the Technische Universität München reprocessed more than 10 years of GPS data in order to generate a consistent set of nadir-dependent phase-center variations (PCVs) and offsets in the z-direction pointing toward the Earth for all GPS satellites in orbit during that period. The agreement between the two solutions estimated by independent software packages is better than 1 mm for the PCVs and about 4 cm for the z-offsets. In addition, the long time-series facilitates the study of correlations of the satellite antenna corrections with several other parameters such as the global terrestrial scale or the orientation of the orbital planes with respect to the Sun. Finally, completely reprocessed GPS solutions using different phase-center correction models demonstrate the benefits from switching from relative to absolute antenna phase-center corrections. For example, tropospheric zenith delay biases between GPS and very long baseline interferometry (VLBI), as well as the drift of the terrestrial scale, are reduced and the GPS orbit consistency is improved.  相似文献   

Technology transfer in the CDM: the role of host-country characteristics     

Gisèle Schmid 《Climate Policy》2013,13(6):722-740

Technology transfer is not an explicit objective of the Clean Development Mechanism (CDM). However, it constitutes a potential co-benefit by helping to improve living conditions in developing countries. Understanding the drivers and barriers of technology transfer in CDM projects is therefore essential to direct investment flows in host countries and enhance the current CDM framework. In this respect, the contribution of this article is twofold. First, it identifies stepping stones and stumbling blocks to technology transfer in the CDM. Higher applied tariff rates on environmental goods and services as well as burdensome administrative procedures to start a new business are found to be negatively associated with the likelihood of a technology transfer. The results are robust to the exclusion of large host countries such as China and India from the sample. Second, as an extension, the article analyses the correspondence of these supporting factors and barriers with the likelihood of a transfer of the different types of technology (equipment, knowledge, or both). The article concludes with policy recommendations for non-Annex I governments, and suggestions for improvements to the CDM to better assess technology transfer in offsetting projects.  相似文献