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Furuno
Furuno Electric Company, to give the organization its proper title, has an extraordinary legacy in marine electronics products. From its home headquarters in
Nishinomiya
City,
Hyogo,
Japan, it has dominated the commercial marine radar market for much of the past 50 years. Its roots lie in the development of the first known fish-finding sonar, around 1950; since then, the company has branched out into radar, navigation, radio equipment, sonar, instrument controls and panels - a wide range of products that are increasingly being integrated into 'glass wheelhouses.'
Furuno is so successful that it routinely scoops half or more of the annual awards of the National Maritime Electronics Association; in 2005, for the thirtieth year in succession, it took the annual NMEA prize for the best development in radar of the previous year. It is hardly surprising, given such a be-medaled history, that the product line has shown great durability, and it is not even remotely unusual for Furuno fishing-boat radars to withstand 10 years' service at sea, making them almost as durable as the craft in which they are installed. This very successful history presents significant challenges in describing the Furuno family - and these challenges are greatly magnified by a growing industry-wide design practice, of flexible architectures and custom configurations. In all, it seems that Furuno employs at least 25 different magnetron versions, many of which may be used as substitutes for others; similarly, there are at least 20 different antenna systems, ranging from hermetically sealed 15" radomes housing printed-circuit arrays to conventional 12' slotted-waveguide antennas. Display types may be even more bewildering with simple 7" monochrome liquid-crystal displays at the low end of the range of complexity and 28" color cathode-ray tubes at the high. The consequence is a catalog comprising hundreds of variations, too complex to be documented in detail here. A somewhat different approach is needed, one which places less emphasis on individual system names, in favor of the hardware. The essential observable and measurable characteristics are broken down in a series of appendices, as follows:
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Appendix 1 provides a naming-convention for Furuno models, distilled from observed usage rather than a deliberate naming policy on the part of the manufacturer. The somewhat-disorganized nature of this apparent convention suggests that there may be several design-centers within the company, each responsible for a distinct product line.
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Appendix 2 summarizes the nominal parameters for today's Furuno product lines, derived entirely from brochures, handbooks and manuals. These should be treated with caution, since the source materials are not entirely consistent, and the available information conveys nothing of the complexities that may be deliberately engineered into the characteristics, for example to satisfy interference-reduction and other product-liability criteria, or to meet IMO mandates regarding scan characteristics for high-speed craft.
o Table 2.1 focuses on the inter-pulse timing characteristic, correlating this to PD for each of the basic models in today's Furuno product line.
o Table 2.2 focuses on the peak-power output, correlating this to physical antenna dimensions.
o Table 2.3 focuses on antenna dynamics from three perspectives. Furuno antennas range in size and form, from 15" radomes (sometimes described as hat-boxes) to 12' arrays, and there are at least 20 variations. Some of these variations stem from changing regulations, which mandate a much greater rotation rate for high-speed craft than for the typically sluggish high-seas traffic: radomes which can accommodate this requirement clearly will have a different form-factor from those that cannot. Generalizing, long array antennas will rarely be found on small craft. Radomes are preferred on these for numerous reasons - the moving hazard represented by long arrays, and the capacity for self-leveling of radomes, to name but two. With such wide variation, Table 2.3 is split into 3 parts, covering radomes, X-band arrays and S-band arrays.
o There is no table summarizing RF behavior, since there are only two RF values to consider: at 10-cm wavelengths, 3050 MHz ± 30 MHz; and, at 3-cm wavelengths, 9410-9415 MHz ± 30 MHz.
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Following these tabulations of published characteristics, Appendix 3 (available by subscription only) explores the physical and measured characteristics of several Furuno systems in the inventory of the Naval Research Laboratory, describing both physical observations and the signal characterization methodology where appropriate.
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