Emitter velocity estimation comparison for frequency difference of arrival measurement based single and multiple reference lateration algorithm

The accuracy at which the instantaneous velocity and position of a non-stationary emitting source estimated using a lateration algorithm depends on several factors such as the lateration algorithm approach, the number and choice of reference receiving station (RS) used in developing the lateration algorithm. In this paper, the use of multiple reference RSs was proposed to improve the velocity estimation accuracy of the frequency difference of arrival (FDOA) based lateration algorithm. The velocity estimation performance of the proposed multiple reference FDOA based lateration algorithm is compared with the conventional approach of using single reference RS at some selected emitter positions using Monte Carlo simulation. Simulation result based on an equilateral triangle RS configuration shows that the use of multiple reference RSs improved the velocity estimation accuracy of the lateration algorithm. Based on the selected emitter positions, a reduction in velocity estimation error of about 0.033m/s and 1.31 m/s for emitter positions at ranges 0.5 km and 5 km respectively was achieved using the multiple reference lateration algorithm

Synthesis of Mn(II) and Fe(II) Complexes with Ethylenediamine and Acetylacetonate Ligands

Synthesis of acetylacetonato, ethylenediamine manganese (II) complex and acetylacetonato, ethylenediamine iron (II) complex were carried out, a pale yellow and brown solids were obtained from the reaction.  The solubility tests of the complexes were carried out, in which manganese (II) complex was found to be soluble in water, methanol and ethanol and insoluble in chloroform and petroleum ether while the iron (II) complex was found to be slightly soluble in water, methanol and ethanol and insoluble in chloroform and petroleum ether. The UV visible spectra of manganese (II) complex showed absorption maximum at around 480nm, and infrared spectra of manganese (II) complex showed absorption band at 1725cm-1. Keywords: Acetylacetone, manganese, iron, ethylenediamine

2-Dimensional position error bias analysis of an angle of arrival based target locating system

An angle of arrival (AOA) based locating system determines the location of an emitting target using its emission detected at spatially deployed ground station (GS) with an angulation algorithm. The position estimation (PE) accuracy of the system depends on several factors one of which is the approach to the development of the angulation algorithm. For passive target locating, the closed-form angulation algorithm is used and has been known to introduce bias in the PE process. In this paper, a bias analysis of the closed-form angulation algorithm is carried out to determine its percentage in the overall position mean square error (MSE). The analysis is carried out using a three-GS triangular configuration at some randomly selected unmanned aerial vehicle (UAV) drone locations. Monte Carlo simulation result based on 200 realizations shows that the bias error introduced by the angulation algorithm in the overall position MSE is about 64%. With the knowledge of the bias percentage, the actual locations of the UAV drones within the AOA-based locating system coverage can be determined

Effect of Path Loss Propagation Model on the Position Estimation Accuracy of a 3-Dimensional Minimum Configuration Multilateration System

The 3-Dimensional (3-D) position estimation (PE) accuracy of a multilateration (MLAT) system depends on several factors one of which is the accuracy at which the time difference of arrival (TDOA) measurements are obtained. In this paper, signal attenuation is considered the major contributor to the TDOA estimation error and the effect of the signal attenuation based on path loss propagation model on the PE accuracy of the MLAT system is determined. The two path loss propagation models are considered namely: Okumura-Hata and the free space path loss (FSPL) model. The transmitter and receiver parameters used for the analysis are based on actual system used in the civil aviation. Monte Carlo simulation result based on square ground receiving station (GRS) configuration and at selected aircraft positions shows that the MLAT system with the Okumura-Hata model has the highest PE error. The horizontal coordinate and altitude error obtained with the Okumura-Hata are 2.5 km and 0.6 km respectively higher than that obtained with the FSPL mode

Development of a 2-dimensional angulation algorithm target locating error estimation technique

A multiangulation (MANG) system determines an emitting target location using the angle of arrival (AOA) measurement estimated from its emission with an angulation algorithm. Prior to deployment of the system, it is important to know if the horizontal coordinate (HC) root mean square error (RMSE)s obtained by the system at certain target locations given an AOA error are within approved standards set by the international regulatory bodies. For this reason, a MANG system target locating error estimation technique based on Euclidean geometrical analysis and linear regression is proposed in this paper. This is to assist in the systematic determination and prediction of the HC RMSE obtained by the angulation algorithm of the MANG system. The proposed technique is validated by comparison with the Monte Carlo (MC) simulation at some randomly selected target locations using a square receiving station (RS) configuration. Result comparison shows that the proposed technique predicts the target HC RMSE obtained by the angulation algorithm within a system coverage of 10 km by 10 km with a prediction accuracy of about ±5 m.Keywords: Multiangulation system; Angle of arrival: Angulation Algorithm; Error prediction; Linear regressio

Direct and indirect TDOA estimation based multilateration system position estimation accuracy comparison

Multilateration (MLAT) system estimate aircraft position from its electromagnetic emission using time difference of arrival (TDOA) estimated at ground receiving station (GRS)s with a lateration algorithm. The position estimation (PE) accuracy of the MLAT system depends on several factors one of which is the TDOA estimation approach. In this paper, the PE performance of a minimum configuration 3-dimensional (3-D) MLAT system based on the direct and indirect approaches to TDOA estimation is presented. The analysis is carried out using Monte Carlo simulation with the transmitter and receiver parameters based on an actual system used in the civil aviation. Simulation results show that within 150 km radius, the direct TDOA based MLAT system performs better than the indirect TDOA based MLAT system. Beyond 150 km radius, the indirect TDOA based MLAT system has the least PE error compared the direct TDOA based MLAT system. Further comparison of the MLAT system based on the two TDOA estimation approaches with other surveillance systems shows that the direct TDOA based MLAT system has the least PE error within 150 km radius while long-range aircraft PE beyond 150 km, automatic surveillance dependent broadcast (ADS-B) outperformed the MLAT system as it has the least PE error

Mitigating the Signaling Resources Expended in 5G Location Management Procedures at Millimeter-Wave Frequencies

The signaling resources expended and the power consumed by User Equipments (UEs) in the Location Management (LM) procedures are expected to be higher in Fifth Generation (5G) than in legacy wireless communications networks. To mitigate this challenge, this work proposes a hybrid scheme that mitigates the signaling resources expended in paging and RAN-based Notification Area Update (RNAU) procedures in 5G. The approach utilizes a hybrid scheme that embeds a UE Identifier (UEID) partitioning scheme that directional pages UEs into a gNB-based UE Mobility Tracking (UEMT) scheme. The approach configures a gNB in an RRC_Inactive state to beam sweep a UEs last registered cell area before directionally paging the UE. The approach proposed in this work is implemented on a modified network architecture to reduce the signaling resources expended on both paging and RNAU of UEs at higher frequencies which is an enabling factor for mmWave systems. Simulation results of the total accumu- lated cost of paging showed a 65.13 % and 8.69 % reduction in signaling resources expended against the conventional approach and the existing gNB-based UEMT approach, respectively. Additionally, the total accumulated resources expended in both procedures over 24 hours showed that the modified gNB-based UEMT scheme outperformed the conventional scheme and the gNB-based UEMT scheme by 90.96 % and 38.36 %, respectively

Genetic gains in grain yield of a maize population improved through marker assisted recurrent selection under stress and non-stress conditions in west Africa

Open Access JournakMarker-assisted recurrent selection (MARS) is a breeding method used to accumulate favorable alleles that for example confer tolerance to drought in inbred lines from several genomic regions within a single population. A bi-parental cross formed from two parents that combine resistance to Striga hermonthica with drought tolerance, which was improved through MARS, was used to assess changes in the frequency of favorable alleles and its impact on inbred line improvement. A total of 200 testcrosses of randomly selected S1 lines derived from the original (C0) and advanced selection cycles of this bi-parental population, were evaluated under drought stress (DS) and well-watered (WW) conditions at Ikenne and under artificial Striga infestation at Abuja and Mokwa in Nigeria in 2014 and 2015. Also, 60 randomly selected S1 lines each derived from the four cycles (C0, C1, C2, C3) were genotyped with 233 SNP markers using KASP assay. The results showed that the frequency of favorable alleles increased with MARS in the bi-parental population with none of the markers showing fixation. The gain in grain yield was not significant under DS condition due to the combined effect of DS and armyworm infestation in 2015. Because the parents used for developing the bi-parental cross combined tolerance to drought with resistance to Striga, improvement in grain yield under DS did not result in undesirable changes in resistance to the parasite in the bi-parental maize population improved through MARS. MARS increased the mean number of combinations of favorable alleles in S1 lines from 114 in C0 to 124 in C3. The level of heterozygosity decreased by 15%, while homozygosity increased by 13% due to the loss of some genotypes in the population. This study demonstrated the effectiveness of MARS in increasing the frequency of favorable alleles for tolerance to drought without disrupting the level of resistance to Striga in a bi-parental population targeted as a source of improved maize inbred lines

Drone’s node placement algorithm with routing protocols to enhance surveillance

Flying ad-hoc network (FANET) is characterized by key component features such as communication scheme, energy awareness, and task distribution. In this research, a surveillance space considering standard petroleum pipe was created with three drones viz: drone 1 (D1), master drone (DM), and drone 2 (D2) to survey as FANET. DM aggregate packets from D1, D2 and communicate with the static ground control station (SGCS). The starting point of the three drones and their trajectories during deployment were calculated and simulated. Selection of DM, D1, and D2 was done using battery level before take-off. Simulation results show take-off time difference which depends on the distance of each drone to the SGCS during deployment. D1 take-off first, while DM and D2 followed after 0.0704 and 0.1314 ms respectively. The position-oriented routing protocols results indicated variation of information flow within time notch due to variation in the density of the transmitted packets. Packets delivery periods are 0.00136×103 sec, 0.00110×103 sec, and 0.00246×103 sec for time notch 1, 2, and aggregating time notch respectively. From the results obtained, two algorithms were used successfully in deploying the drone