Troposphere

Today, Global Positioning System (GPS) is widely used in almost every aspect of our daily life. Commonly,
users utilize the technology to track the position of a vehicle or an object of interest. They also use it to
safely navigate to the destination of their choice. As a result, there are countless number of GPS based
tracking application that has been developed. But, a main recurring issue that exists among these
applications are the inaccuracy of the tracking faced by users and this issue has become a rising concern.
Most existing research have examined the effects that the inaccuracy of GPS have on users while others
identified suitable methods to improve the accuracy of GPS based on one or two factors. The objective of
this survey paper is to identify the common factors that affects the accuracy of GPS and identify an effective
method which could mitigate or overcome most of those factors. As part of our research, we conducted a
thorough examination of the existing factors for GPS inaccuracies. According to an initial survey that we
have collected, most of the respondents has faced some form of GPS inaccuracy. Among the common issues
faced are inaccurate object tracking and disconnection of GPS signal while using an application. As such,
most of the respondents agree that it is necessary to improve the accuracy of GPS. This leads to another
objective of this paper, which is to examine and evaluate existing methods as well as to identify the most
effective method that could improve the accuracy of GPS.

Contains the viewgraphs and other materials for the 48 papers presented at the 18th annual review conference on atmospheric transmission models held at the geophysics directorate, Phillips Laboratory (AFMC), Hanscom AFB, MA ON: 6-8 June 1995.

This is the third of a three-part investigation into tropical cyclone (TC) genesis in the Australian Bureau of Meteorology’s Tropical Cyclone Limited Area Prediction System (TC-LAPS), an operational numerical weather prediction (NWP) forecast model. In Parts I and II, a primary and two secondary vortex enhancement mechanisms were illustrated, and shown to be responsible for TC genesis in a simulation of TC Chris. In this paper, five more TC-LAPS simulations are investigated: three developing and two nondeveloping. In each developing simulation the pathway to genesis was essentially the same as that reported in Part II. Potential vorticity (PV) cores developed through low- to middle-tropospheric vortex enhancement in model-resolved updraft cores (primary mechanism) and interacted to form larger cores through diabatic upscale vortex cascade (secondary mechanism). On the system scale, vortex intensification resulted from the large-scale mass redistribution forced by the upward mass flu...

In the design of radiowave links, one of the major concerns is the amount of time for which the link is out of service. The outage could be due to equipment failure or propagation condi tions. Our concern here is outage due to rain. For this reason a rain map for radiowave propagation in Saudi Arabia is developed. Based on IS-year rainfall data for all regions of Saudi Arabia, a rain map sui table for propagation studies is presented. According to this five climate regions have been established to describe the different regions of Saudi Arabia. I.

... Furthermore, the impact of precipitation on AOD, aerosol size and properties has a ... Data acquiredover the Pacific Ocean indicate, generally, a more transparent atmosphere, compared to thatover the Atlantic Ocean or seas, like the Mediterranean (Smirnov et al., 2002b). ...