HD Digital Radar

Is There Really A Difference?

FSF Staff June 5, 2009

For many years radar has remained tried and true in the analog world. Well, times have changed and digital radar is finally here with such buzz words as HD, Super Digital, Ultra High Definition and Broadband. What does all this mean to the average boater, and what improvements do these advanced systems offer? Let’s start with the basics.

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Photo: Raymarine

Traditional radars emit microwave pulses with analog amplifiers, filters and limiters. A measurement is calculated to determine how long it takes for the wave to bounce back and the difference in time is then translated into an on-screen image. Due to component tolerances it becomes difficult to modify the signal or upgrade performance with analog radar systems. Digital radars do not utilize microwave pulses, but rather a continuous signal. This allows for low distortion of original information. Digital signal processing is mathematically driven and not component driven. It leaves a very predictable performance with no tolerance issues and allows for future features and performance upgrades via software instead of replacing costly hardware. Digital radar offers boaters greater target definition and clarity and even uneducated radar users can utilize overlay features to get a better idea of their situational awareness.

…an increasing number of enthusiastic anglers are utilizing high-performance radar systems to locate flocks of birds and in turn, feeding game fish.

In layman’s terms here are some of the advantages of digital radar systems:

  • They use a processor that is 25 times more powerful, which gives users more information and processes up to 256 colors and graded target returns.
  • Greatly enhanced signal to noise ratios, which improve small target detection especially in rough seas or heavy rain.
  • It allows the user to have true dual range radar with the ability to see targets on long and short ranges at the same time with no loss of detection capabilities.
  • Presets that enable users to have “one touch” settings for locating birds, bad weather conditions, offshore cruising and harbor settings.

Whether you’re buying a radar system for the first time or replacing a dated system, it’s important to consider how you plan on using the radar in choosing what’s best for you. Radars are available in two different antenna types – dome and open array. The dome radar is the most commonly used system for small boats because they’re compact and typically less expensive than open array versions. Open array radars on the other hand are for the boater who wants to have the ultimate system in place to locate birds or for safely operating in harsh weather conditions.

In today’s day and age an increasing number of enthusiastic anglers are utilizing high-performance radar systems to locate flocks of birds and in turn, feeding game fish. If you want to search for birds with your radar the most important aspect to consider is antenna beamwidth. Beamwidth is the horizontal or vertical angle of the radar signal, and the narrower the beamwidth the greater the target discrimination. Because of this, open array radars are better suited for identifying individual targets and small flocks of flying birds. If you’re an inexperienced radar user and avid blue water angler interested in locating reliable feathered fish finders, set your radar to mid or long-range and set the gain to full. If your radar can operate in true motion, use it (true motion will reveal objects moving in accordance with your vessel, while objects at rest will remain stationary). This will help determine whether the birds you’re targeting are diving and feeding or on the move hot on the tails of hunting game fish.

How much power do I need you ask? Why do I need a 64nm radar when I only want to see birds at 3 to 6nm? In order to locate birds we recommend a minimum of 10kw of power. While this setup will offer ranges up to 64nm, do not expect to spot targets 64nm away due to the curvature of the earth. Precisely how far in the distance radar can see depends on three key factors. How high the antenna is mounted on the boat, what the power output of the radar system is, and the overall size and height of your target.

So ultimately, the answer is “YES,” there are significant advantages in capabilities and performance with today’s HD digital radars. The many benefits associated with this new technology far outweigh the small difference in cost versus traditional analog systems.

To better help you in making a final purchasing decision it’s best to seek out your local marine electronics dealer to help you choose the appropriate brand and model for your particular application and desires. In order to obtain maximum performance, it’s extremely important and highly recommended that your radar system is installed by a certified FCC radar technician.

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