Search Results - (Author, Cooperation:D. Kuang)

2015-11-07

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Basic Helix-Loop-Helix Transcription Factors/genetics ; Cyclic Nucleotide-Gated Cation Channels/genetics ; *Gene Expression Regulation, Developmental ; Genetic Loci ; Genetic Markers ; Mice ; Mice, Inbred C57BL ; Neural Stem Cells/*metabolism ; Neurogenesis/*genetics ; Olfactory Mucosa/innervation ; Olfactory Receptor Neurons/*metabolism ; Receptors, Odorant/*genetics ; Sequence Analysis, RNA ; Single-Cell Analysis ; Smell/*genetics ; Transcriptome

1432-1394

Springer Online Journal Archives 1860-2000

Architecture, Civil Engineering, Surveying

Abstract High precision geodetic applications of the Global Positioning System (GPS) require highly precise ephemerides of the GPS satellites. An accurate model for the non-gravitational forces on the GPS satellites is a key to high quality GPS orbit determination, especially in long arcs. In this paper the effect of the satellite solar panel orientation error is investigated. These effects are approximated by empirical functions to model the satellite attitude variation in long arc orbit fit. Experiments show that major part of the long arc GPS orbit errors can be accommodated by introducing a periodic variation of the satellite solar panel orientation with respect to the satellite-Sun direction, the desired direction for solar panel normal vector, with an amplitude of about 1 degree and with a frequency of once per orbit revolution.

Electronic Resource

1432-1394

Springer Online Journal Archives 1860-2000

Architecture, Civil Engineering, Surveying

Abstract. High precision geodetic application of the Global Positioning System (GPS) require highly precise ephemerides of the GPS satellites. An accurate model for the non-gravitational forces on the GPS satellites is a key to high quality GPS orbit determination, especially in long arcs. In this paper the effect of the satellite solar panel orientation error is investigated. These effects are approximated by empirical functions to model the satellite attitude variation in long arc orbit fit. Experiments show that major part of the long arc GPS orbit errors can be accommodated by introducing a periodic variation of the satellite solar panel orientation with respect to the satellite-Sun direction, the desired direction for solar panel normal vector, with an amplitude of about 1 degree and with a frequency of once per orbit revolution.

Electronic Resource

1432-1394

Springer Online Journal Archives 1860-2000

Architecture, Civil Engineering, Surveying

Abstract. The geometric information from observables of the Global Positioning System is analyzed through the eigenvectors of the normal matrix in the positioning estimation problem. The relationship among observability, bias absorption and loss of information in differencing measurements is addressed. Some general conclusions for point positioning and relative positioning problems are drawn from analytic inference and supported by numerical simulations.

Electronic Resource

1432-1394

Springer Online Journal Archives 1860-2000

Architecture, Civil Engineering, Surveying

Abstract The Southwest Pacific GPS Project (SWP) is using the Global Positioning System (GPS) to monitor crustal motion across and within a plate boundary complex between the Australian and Pacific plates. GPS field campaigns were conducted in 1988, 1989 and 1990, to observe networks of increasing size and complexity. The 1990 campaign consisted of two periods, or “Bursts”, and this paper focuses on the analysis of data collected during the nine day Burst 1 in July, 1990, a period in which GPS Selective Availability was activated. During Burst 1, baselines that spanned the Tonga Trench and the Lau Basin were observed, and only one station (Espiritu Santo, Vanuatu) was located west of Fiji in the network. The lengths of the baselines observed fall mainly between 300 km and 1600 km, but some lines are as long as 3500 km. A total of 78 station-days of field site data and approximately 150 station-days of global fiducial data were processed from predominantly codeless receivers. A global fiducial network of 20 sites was used to provide orbit control and accuracy assessment for the 13 available satellites. The daily solutions for 45 baselines between 10 SWP sites have an RMS scatter in the length of 24 mm plus 6 parts per billion. This scatter provides an estimate of baseline precision for the Burst 1 “nominal solution.” Experiments were conducted to investigate a variety of possible effects on the SWP Network baseline estimates, including the influence of a reduced global fiducial network for the purpose of assessing the quality of results obtained in 1988 and 1989 in which the fiducial network was smaller than in 1990. These experiments produced results that agreed with the nominal solution at the level of the precision estimate. Furthermore, estimates for selected baselines in Australia, the Central Pacific, North America and Europe, also measured by VLBI and SLR, were used for an external accuracy evaluation. The GPS and VLBI or SLR determinations of length agreed at a level consistent with the nominal solution precision estimate.

Electronic Resource