IJITEE, Vol. 4, No. 1, March 2020 Ahmad Nugroho Jati: A High-Frequency Surface Wave ... ISSN 2550 – 0554 (Online) A High-Frequency Surface Wave Radar Simulation Using FMCW Technique for Ship Detection Ahmad Nugroho Jati 1 , Ahmad Fauzi Haqqoni 1 , Iswandi 1 , Risanuri Hidayat 1 Abstract—Indonesia is an archipelagic country with a vast sea area. This vast sea area becomes a challenge in conducting regional surveillance to maintain maritime conditions. The use of buoys and satellites still has shortcomings in carrying out surveillance despite its excellent surveillance capabilities. A high- frequency radar technology with 3-30 MHz frequency and surface wave propagation are very suitable because it has a radar range that can cross the horizon or commonly refer to as Over the Horizon (OTH). The Frequency Modulated Continuous Wave (FMCW) technique on this radar obtains distance and velocity information by a continuously transmitted frequency modulation. The use of radar in Indonesia for marine surveillance is still infrequent. Therefore, it is relatively difficult to conduct testing and obtain data. In addition, the direct examination requires extended time, so a simulation program is needed. This paper discusses the design of a High-Frequency Surface Wave Radar (HFSWR) simulation program using FMCW modulation technique. The simulation program detected two objects based on time delays due to the distance and velocity of the object with a maximum range of 350 km. It displayed the results in an informative manner. The object detection was based on the results of the Fast Fourier Transform (FFT) from the mixed signals. The mixed signal is a combination of transmitted signal and reflected signal in which there are time delay components due to the object. The simulation program had been tested with input values of distance and velocity that vary, both for one object and two objects, in the radial direction. It generated output that was close to the input value with a level of accuracy of ± 2 km. Keywords—Fast Fourier Transform, FMCW, Doppler Frequency, HFSWR, Radar. I. INTRODUCTION Indonesia is an archipelagic country with an extensive area, namely, the land area of 1,904,569 km 2 , a water area of 6,315,222 km 2 , and a coastline length of 108,000 km [1]. Radar has a significant role in Indonesia with such a large area to maintain the security. The HF radar technology is frequently used in the fields of oceanography or ocean monitoring with extensive water conditions and lengthy coastlines [2]. A radar using a surface wave propagation type is also called a High-Frequency Surface Wave Radar (HFSWR) [3]. The HFSWR is very suitable for ocean monitoring because with a frequency of 3-30 MHz, the radar range can cross the horizon, or it is commonly called as Over the Horizon (OTH) [4]. The HFSWR is one of the other radar replacement innovations that has several shortcomings. One of them is the Automatic Identification System (AIS) that can be manually turned off by shipowners. Another weakness is the Synthetic Aperture Radar (SAR) that cannot be updated at any time because it depends on the satellites, aircraft or Unmanned Aerial Vehicle (UAV) that pass through that area [5]-[7]. The HFSWR uses an FMCW modulation technique, which is a radar modulation technique that can obtain distance information using a continuously transmitted frequency modulation [8]. In general, the Frequency Modulated Continuous Wave (FMCW) radar technology requires a very low transmit power compared to other radar types [9], [10]. Some of these advantages made the FMCW radar selected from several different modulation types, such as pulse radar, Frequency Modulated Interrupted Continuous Wave (FMICW), and multi-frequency continuous wave [11], [12]. Radar is a complex system with empirical data covering many parameters and natural factors, as well as direct observations that take a long time. Therefore, simulation is needed to observe how the radar detects a target and obtains information about distance and velocity as well as displays information in an informative manner. This paper aims to create an HFSWR simulation program with FMCW as the modulation technique to detect ship which has a certain velocity and distance from the radar source. The target ships used are considered to have the same shape. The influence of ocean waves, noise, and clutter are not considered in simulation because more research still to be done to see the effects on reflected waves of objects. The detection results of the simulation program were displayed in the form of a range- velocity map showing the distance and velocity of each object. The object movements are displayed with animation to see the radial motion of an object. II. HIGH-FREQUENCY SURFACE WAVE RADAR A High Frequency Radar (HFR) is radio equipment that transmits electromagnetic waves in high-frequency bands between 3-30 MHz, with the wavelengths ranging from 10 m to 100 m, with a radar range as far as 350 km [13]. Two HFR types are divided based on how the radio waves propagate, namely, HFR with wave propagation in the sky (skywave) and HFR with a wave propagation on the surface (surface wave). Skywaves propagate through the ionosphere reflection and detect targets on the horizon. This technique is mainly used for remote tracking, but it has spatial resolution limitations. This section focuses on discussing surface waves or commonly called HFSWR, which are used for sea-level observations. The basic principle of this technique is to utilize the wave reflection energy (backscatter) from the seawater 1 Department of Electrical and Information Engineering Universitas Gadjah Mada, Jl. Grafika No. 2, Bulaksumur, Yogyakarta 55281 INDONESIA (telp: 0274-552305; fax: 0274- 552305; e-mail: ahmad.nugroho.j@mail.ugm.ac.id, ahmad.fauzi.h@mail.ugm.ac.id, iswandi@ugm.ac.id, risanuri@ugm.ac.id ) 19 brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by IJITEE (International Journal of Information Technology and Electrical Engineering)