User manual FURUNO FAR-2837S

[. . . ] MARINE RADAR/ARPA FAR-28x7 Series FAR-21x7(-BB) Series Your Local Agent/Dealer 9-52 Ashihara-cho, Nishinomiya 662-8580, JAPAN Telephone : Fax : 0798-65-2111 0798-65-4200 All rights reserved. Printed in Japan FIRST EDITION : JAN 2004 . OME-35190 ( DAMI ) FAR-2107/2807 SER. *00014745202* *00014745202* *00014745202* *OME35190C00* *OME35190C00* *OME35190C00* SAFETY INSTRUCTIONS WARNING Radio Frequency Radiation Hazard The radar antenna emits electromagnetic radio frequency (RF) energy which can be harmful, particularly to your eyes. Never look directly into the antenna aperture from a close distance while the radar is in operation or expose yourself to the transmitting antenna at a close distance. Distances at which RF radiation levels of 100 and 10 W/m2 exist are given in the table below. [. . . ] The Rmax is given in the following equation. R max = 2. 2 x ( h1 + h2 ) where Rmax: radar horizon (nautical miles) h1: antenna height (m) h2 : target height (m) Radar horizon Optical horizon For example, if the height of the antenna above the waterline is 9 meters and the height of the target is 16 meters, the maximum radar range is; R max= 2. 2 x ( 9 + 16 ) = 2. 2 x (3 + 4) = 15. 4 nm It should be noted that the detection range is reduced by precipitation (which absorbs the radar signal). 2-1 2. RADAR OBSERVATION X-band and S-band In fair weather, the equation on the previous page does not give a significant difference between X- and S-band radars. However, in heavy precipitation condition, an S-band radar would have better detection than an X-band radar. Radar resolution There are two important factors in radar resolution (discrimination): bearing resolution and range resolution. Bearing resolution Bearing resolution is the ability of the radar to display as separate pips the echoes received from two targets which are at the same range and close together. It is proportional to the antenna length and reciprocally proportional to the wavelength. The length of the antenna radiator should be chosen for a bearing resolution better than 2. 5° (IMO Resolution). This condition is normally satisfied with a radiator of 1. 2 m (4 ft) or longer in the X-band. The S-band radar requires a radiator of about 12 feet (3. 6 m) or longer. Range resolution Range resolution is the ability to display as separate pips the echoes received from two targets which are on the same bearing and close to each other. Practically, a 0. 08 microsecond pulse offers the discrimination better than 35 m as do so with all FURUNO radars. Test targets for determining the range and bearing resolution are radar reflectors having an echoing area of 10 m2. Bearing accuracy One of the most important features of the radar is how accurately the bearing of a target can be measured. The accuracy of bearing measurement basically depends on the narrowness of the radar beam. However, the bearing is usually taken relative to the ship's heading, and thus, proper adjustment of the heading line at installation is an important factor in ensuring bearing accuracy. To minimize error when measuring the bearing of a target, put the target echo at the extreme position on the screen by selecting a suitable range. Range measurement Measurement of the range to a target is also a very important function of the radar. Generally, there are two means of measuring range: the fixed range rings and the variable range marker (VRM). The fixed range rings appear on the screen with a predetermined interval and provide a rough estimate of the range to a target. The variable range marker's diameter is increased or decreased so that the marker touches the inner edge of the target, allowing the operator to obtain more accurate range measurements. 2-2 2. RADAR OBSERVATION 2. 2 False Echoes Occasionally echo signals appear on the screen at positions where there is no target or disappear even if there are targets. They are, however, recognized if you understand the reason why they are displayed. [. . . ] 1-44, 3-24 ALARM ACK key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-44 ALARM box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-43 Alarms description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-82 output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-84 ANTENNA box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-85 Antenna selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21 CPA and TCPA alarm acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22 criteria for selecting targets for tracking 3-34 factors affecting operation of. . . . . . . . . . . . . . . . . 3-25 guard zone violation acknowledgement 3-24 manual acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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