Josaphat Tetuko Sri Sumantyo, Josaphat Tetuko Sri
Center for Environmental Remote Sensing, Chiba University1-33 Yayoi, Inage, Chiba 263-8522, Japan

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Dual-Band Singly-Fed Proximity-Coupled Tip-Truncated Triangular Patch Array for Land Vehicle Mobile System Basari, Basari; Sumantyo, Josaphat Tetuko Sri
Makara Journal of Technology Vol. 19, No. 3
Publisher : UI Scholars Hub

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Abstract

This paper proposes a dual-band left-handed circularly polarized triangular-patch array that is developed for land vehicle mobile system aimed at mobile satellite communications. The array consists of six tip-truncated triangular patches, which the first three patches are used for reception and the second three patches are used for transmission purpose. Each of three-patches has a beam pattern that can be switched in three different 120°-coverage beam in azimuth-cut plane at a minimum targeted gain at a desired elevation angle. The targeted minimum gain of the array is 5 dBic, in order for data communications with a large geostationary satellite can be achieved. The array is able to operate in two different frequency bands i.e. 2.50 GHz band for reception (down-link) and 2.65 GHz band for transmission (uplink). The array is simulated using the Method of Moments-based software (Ansoft Maxwell), fabricated and measured to confirm the simulated results. The measurement results show that the 5dBic-gain and the 3dB-axial ratio of the reception elements cover all of 360° azimuth direction. In the case of transmission elements, 4.3dBic-gain and the 3dBaxial ratio can be obtained.
Grid-Based Ship Density Analysis and Anomaly Detection for Ship Movements Monitoring at Tanjung Priok Port Ikhsan, Muhammad Ramadhan; Pamungkasari, Panca Dewi; Purbantoro, Babag; Sholihati, Ira Diana; Farahdinna, Frenda; Sumantyo, Josaphat Tetuko Sri; Heezen, Damy Matheus
International Journal of Advances in Data and Information Systems Vol. 6 No. 1 (2025): April 2025 - International Journal of Advances in Data and Information Systems
Publisher : Indonesian Scientific Journal

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59395/ijadis.v6i1.1367

Abstract

Indonesia, as a maritime country, depends on ports to support inter-island transport and a smooth regional economy. So, the awareness of knowing the marine status with various platforms is needed. This research distinguishes itself from several previous studies on ship movement detection by concentrating specifically on anomalies in ship movement within areas of high traffic density. This research proposes to find out the ship density area using the grid technique and identify the anomalies that have occurred, as information on ship movements at Tanjung Priok Port. Anomaly detection is done by looking for it through visualization, where AIS data is converted into a form of visualization using the Python language. The results obtained two pieces of information, namely that the areas with the highest density are around the harbor, docks, and ship lanes. Then, two types of anomalies were detected, namely large ships with dangerous cargo speeding in dense areas and ships that behave differently compared to other ships with the same status.
Analysis of unmanned aerial vehicle airframe materials on circularly polarized antenna radiation characteristics Wahyudi, Wahyudi; Setyadewi, Imas Tri; Sakti, Mohammad Amanta Kumala; Prabowo, Yanuar; Hadiyanti, Donatina Miswati; Rahayu, Novelita; Muzayadah, Nurul Lailatul; Wahyudi, Agus Hendra; Guno, Yomi; Praludi, Teguh; Santosa, Cahya Edi; Sumantyo, Josaphat Tetuko Sri
Bulletin of Electrical Engineering and Informatics Vol 14, No 4: August 2025
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v14i4.8010

Abstract

This paper presents an experimental examination of how unmanned aerial vehicle (UAV) airframe materials affect the electromagnetic characteristics of the airborne circularly polarized (CP) payload antenna. This study specifically investigates the received signal from the circularly polarized synthetic aperture radar (CP-SAR) antenna installed within the fuselage of the lapan surveillance UAV (LSU). In the airborne CP-SAR experiment, broadband CP microstrip subarray antennas were used along with LSU series airframe material composites comprising E-glass EW-185 and Carbon C522 Twill. The composite specimens were prepared to have the same size and thickness to minimize variability in the comparative analysis. The experimental study measures the transmission loss using S-parameters. At 5.3 GHz, the E-glass EW-185 fiber composite exhibits a material attenuation of -1.5 dB and a circular depolarization of 0.32 dB. The E-glass EW-185 fiber composite exhibits a material attenuation of -1.5 dB and a circular depolarization of 0.32 dB. In contrast, the Carbon C522 Twill fiber composite demonstrates a significantly higher material attenuation of -31.24 dB and a circular depolarization of 10.70 dB. Additionally, this paper examines the radiation pattern measurements of the CP-SAR antenna at various frequencies, providing a comprehensive analysis of the materials' impact on antenna performance.