In the Joint Precision Approach and Landing System (JPALS) both the differential GPS reference station and the airborne user will employ Controlled Reception Pattern Array (CRPA) antennas. In a high precision system such as JPALS, CRPA antennas may suffer phase center biases that introduce significant integrity risk. These phase center biases result from both hardware design and from algorithm ...

Quantitative optical spectroscopy has the potential to provide an effective low cost, and portable solution for cervical pre-cancer screening in resource-limited communities. However, clinical studies to validate the use of this technology in resource-limited settings require low power consumption and good quality control that is minimally influenced by the operator or variable environmental co...

BACKGROUND A study was undertaken to test the long term performance of a small hand held spirometer for self-administered serial spirometric testing. METHODS Thirty turbine pocket spirometers (MicroMedical DiaryCard) were used in a clinical trial on 22 emphysematous patients with severe alpha 1-antitrypsin deficiency. The spirometers were able to store the date, time, forced expiratory volume...

The detection of depth-of-interaction (DOI) is a critical detector capability to improve the PET spatial resolution uniformity across the field-of-view and will significantly enhance, in particular, small bore system performance for brain, breast, and small animal imaging. One promising technique of DOI detection is to use dual-ended-scintillator readout that uses two photon sensors to detect s...

To address drift in chemical sensing, an extensive dataset was collected over a period of three years. An array of 16 metal-oxide gas sensors was exposed to six different volatile organic compounds at different concentration levels under tightly-controlled operating conditions. Moreover, the generated dataset is suitable to tackle a variety of challenges in chemical sensing such as sensor drift...

The Control System for the Advanced Light Source (ALS) at Lawrence Berkeley National Lab (LBNL) uses in-house designed IndustryPack (IP) modules contained in compact PCI (cPCI) crates with 16-bit analog I/O to control instrumentation. To make the IP modules interchangeable, each module is calibrated for gain and offset compensation. We initially developed a method of verifying and calibrating ...

The satellite clocks used in the BeiDou-2 satellite navigation System (BDS) are Chinese self-developed Rb atomic clocks, and their performances and stabilities are worse than GPS and Galileo satellite clocks. Due to special periodic noises and nonlinear system errors existing in the BDS clock offset series, the GPS ultra-rapid clock model, which uses a simple quadratic polynomial plus one perio...

Traditional calibration of dc voltage high accuracy digital voltmeters (DVMs) using conventional and Programmable Josephson Voltage Standards at INMETRO show improvements between 73.7 % and 98.3 % when compared with a regular calibration technique. Some calibration results as well as DVM linearity and gain drift analysis (up to 10 V range) are presented and discussed in this paper.