Instantaneous GPS-Galileo attitude determination: single-frequency performance

New and modernized global navigation satellite systems (GNSSs) are paving the way for an increasing number of applications in positioning, navigation, and timing (PNT). A combined GNSS constellation will significantly increase the number of visible satellites and, thus, will improve the geometry of observed satellites, enabling improvements in navigation solution availability, reliability, and accuracy. In this paper, a global positioning system (GPS) +Galileo robustness analysis is carried out for instantaneous single-frequency GNSS attitude determination. Precise attitude determination using multiple GNSS antennas mounted on a platform relies on successful resolution of the integer carrier-phase ambiguities. The multivariate-constrained least squares ambiguity decorrelation adjustment (MC-LAMBDA) method has been developed to resolve the integer ambiguities of the nonlinearly constrained GNSS attitude model that incorporates the known antenna geometry. In this paper, the method is used to analyze the attitude determination performance of a combined GPS +Galileo system. Special attention is thereby given to the GPS and Galileo intersystem biases (ISBs).The attitude determination performance is evaluated using GPS/Galileo data sets from a hardware-in-the-loop experiment and two real-data campaigns. In the hardware-in-the-loop experiment, a full GPS/Galileo constellation is simulated, and performance analyses are carried out under various satellite-deprived environments, such as urban canyons, open pits, and other satellite outages. In the first real-data experiment, single-frequency GPS data, combined with the data of Galileo in-orbit validation element (GIOVE) satellites GIOVE-A/GIOVE-B (the two experimental Galileo satellites), are used to analyze the two constellation attitude solutions. In the second real-data experiment, we present the results based on single-frequency data from one of the Galileo IOV satellites, combined with the data of GIOVE-A and GPS. We d- monstrate and quantify the improved availability, reliability, and accuracy of attitude determination using the combined constellation

Peace Education Practices in Pre-Service Teacher Training Programs: and Analysis

This study was designed to investigate peace education in pre-service teacher training programs in Khyber Pakhtunkhwa, Pakistan. The objectives of the present study to find out :( a) to examine prevailing practices of peace education in pre-service teacher training programs in Khyber Pakhtunkhwa Pakistan. (b) To evaluate the views of teacher Educators regarding the need of peace education in pre-service teacher training programs in Khyber Pakhtunkhwa Pakistan. (c) To suggest way of integrating peace education in pre-service teacher training programs in Khyber Pakhtunkhwa Pakistan. Using Survey method the data were collected through questionnaire from 245 teachers using simple random technique. A questionnaire was developed to investigate the opinions of the participants of the study. The data was analyzed by using the mean score, frequency and percentage

The Tomb of Nikauisesi : the Teti Cemetery at Saqqara : Vol. 6

74 page(s

The Tombs of Shepsipuptah, Mereri (Merinebti), Hefi and others : The Teti Cemetery at Saqqara : Vol. VII

76 page(s

Mereruka and his family. Part II, the tomb of Waatetkhethor

Waatetkhethor, the eldest daughter of King Teti and wife of the vizier Mereruka, is the only woman buried in the Teti Cemetery who owned a separate chapel and burial chamber in her husband's mastaba. She held a very elevated status and her son, Meryteti, was described as 'eldest son of the king of his body' (see Part I of this publication). The book examines her special position and documents all the scenes and inscriptions in her chapel, both in line drawings and colour photographs, and produces architectural drawings of her tomb

Instantaneous BeiDou–GPS attitude determination: A performance analysis

The advent of modernized and new global navigation satellite systems (GNSS) has enhanced the availability of satellite based positioning, navigation, and timing (PNT) solutions. Specifically, it increases redundancy and yields operational back-up or independence in case of failure or unavailability of one system. Among existing GNSS, the Chinese BeiDou system (BDS) is being developed and will consist of geostationary (GEO) satellites, inclined geosynchronous orbit (IGSO) satellites, and medium-Earth-orbit (MEO) satellites. In this contribution, a BeiDou–GPS robustness analysis is carried out for instantaneous, unaided attitude determination. Precise attitude determination using multiple GNSS antennas mounted on a platform relies on the successful resolution of the integer carrier phase ambiguities. The constrained Least-squares AMBiguity Decorrelation Adjustment (C-LAMBDA) method has been developed for the quadratically constrained GNSS compass model that incorporates the known baseline length. In this contribution the method is used to analyse the attitude determination performance when using the GPS and BeiDou systems. The attitude determination performance is evaluated using GPS/BeiDou data sets from a real data campaign in Australia spanning several days. The study includes the performance analyses of both stand-alone and mixed constellation (GPS/BeiDou) attitude estimation under various satellite deprived environments. We demonstrate and quantify the improved availability and accuracy of attitude determination using the combined constellation

BeiDou inter-satellite-type bias evaluation and calibration for mixed receiver attitude determination

The Chinese BeiDou system (BDS), having different types of satellites, is an important addition to the ever growing system of Global Navigation Satellite Systems (GNSS). It consists of Geostationary Earth Orbit (GEO) satellites, Inclined Geosynchronous Satellite Orbit (IGSO) satellites and Medium Earth Orbit (MEO) satellites. This paper investigates the receiver-dependent bias between these satellite types, for which we coined the name “inter-satellite-type bias” (ISTB), and its impact on mixed receiver attitude determination. Assuming different receiver types may have different delays/biases for different satellite types, we model the differential ISTBs among three BeiDou satellite types and investigate their existence and their impact on mixed receiver attitude determination. Our analyses using the real data sets from Curtin’s GNSS array consisting of different types of BeiDou enabled receivers and series of zero-baseline experiments with BeiDou-enabled receivers reveal the existence of non-zero ISTBs between different BeiDou satellite types. We then analyse the impact of these biases on BeiDou-only attitude determination using the constrained (C-)LAMBDA method, which exploits the knowledge of baseline length. Results demonstrate that these biases could seriously affect the integer ambiguity resolution for attitude determination using mixed receiver types and that a priori correction of these biases will dramatically improve the success rate.Geoscience & Remote SensingCivil Engineering and Geoscience

Flexibility and viscometric studies of globular proteins ovalbumin and ovotransferrin

98-107The ultrasonic velocity, density and viscosity of two egg proteins, ovalbumin and ovotransferrin in phosphate buffer have been studied at the physiological pH values. The thermodynamic functions for unfolding, ellipticity, surface amino acid residues and compressibility have been obtained for thermal and chemical denaturation in these food proteins. The com-puted values of Huggin’s constant and shape factor, at a fixed ionic strength 0.16 M are found to be in agreement with the reported values for globular proteins. The slow increase in free-energy of unfolding with temperature at a fixed pH 7 sug-gests uncoiling and in turn, disappearance of biological activity. It has been observed that the effects of temperature and chemical denaturant on the native protein may give rise to different conformational states. In the presence of urea and so-dium dodecyl sulphate (SDS), the proteins gave the excessively denatured states at 25ºC and pH 7, in comparison to the thermal denatured state. The positive values of partial adiabatic compressibility βs over the temperature range 45-75ºC suggest the possibility of large internal flexibility in ovotransferrin than in ovalbumin

Mereruka and his family. Part I, the tomb of Meryteti

The mastaba of Mereruka is the most extensively decorated tomb of the Old Kingdom. This project intends to document all parts of this tomb beginning with the least accessible to scholars. It is therefore devoted to the chapel and burial chamber of Meryteti, son of Mereruka, grandson of King Teti and vizier of Pepy I

Prospects of organic acids as safe alternative to antibiotics in broiler chickens diet

Genetically, modern broilers are fast-growing birds which attain the market age at the age of 5 weeks. To maintain optimum production, antibiotics have been commonly included in the diets as growth promoters. However, due to the increase in antimicrobial resistance, their uses have been banned worldwide. To keep the optimum level of production and health in broiler industry, the use of alternative growth promoters such as probiotics, prebiotics, enzymes, and organic acids has been proposed. Chemically, organic acids are weak acids and only partially dissociate. They are considered safe and have been used for preservation of food for centuries. Nowadays, organic acids have been reported for antibacterial, immune potentiating, and growth promoters in broilers. In this review, the effects of dietary inclusion of organic acids on growth, nutrient digestibility, intestinal integrity, immune system, and antibacterial activity in broilers are discussed