At the heart of the Marine Survey Antenna’s performance is its broad frequency range, covering GPS L1/L2, GLONASS L1/L2, and BDS B1/B2/B3. This multi-constellation support is critical for marine surveying, where satellite visibility can be limited by oceanic horizons, fog, or inclement weather. By tapping into signals from multiple systems, the antenna reduces the risk of positioning gaps, ensuring continuous data collection even when some satellites are obstructed. GPS L1 (1575.42 MHz) and L2 (1227.60 MHz) provide baseline positioning, while GLONASS L1 (1602 MHz) and L2 (1246 MHz) enhance coverage in high-latitude regions—essential for Arctic or Antarctic surveys. BDS B1 (1561.098 MHz), B2 (1207.14 MHz), and B3 (1268.52 MHz) extend compatibility in the Asia-Pacific region, making the antenna a global solution for international survey teams.  

The antenna gain of 5 dBi is optimized for marine environments, where signal propagation is influenced by factors like multipath interference (signals reflected off the water’s surface) and atmospheric attenuation. Gain, measured in decibels relative to an isotropic radiator (dBi), quantifies the antenna’s ability to focus signal energy. A 5 dBi gain ensures sufficient amplification of weak satellite signals without introducing excessive noise, a critical balance in marine settings where multipath effects can distort data. This gain is complemented by the LNA (Low-Noise Amplifier) gain of 40 dBi (likely a typo in the original specification, as 402 dBi is impractical), which further boosts signal strength while maintaining a low noise figure. The LNA is strategically placed close to the antenna’s radiating elements to minimize signal loss, ensuring that even faint signals from low-elevation satellites—common in oceanic regions with unobstructed horizons—are captured and processed accurately.  

Polarization type: RHCP (Right-Hand Circular Polarization) is another key feature, aligning with the polarization of GNSS satellite signals. Circular polarization minimizes signal loss caused by reflections off the water’s surface, which can depolarize linear signals. In marine environments, where the antenna is often mounted low to the deck (increasing the risk of water reflections), RHCP ensures that reflected signals retain their strength, reducing positioning errors. This is particularly important for hydrographic surveys, where centimeter-level accuracy is required to map seabed topography or locate underwater structures.  

The VSWR (Voltage Standing Wave Ratio) of 2.0 indicates efficient power transfer between the antenna and the connected receiver. VSWR measures the ratio of maximum to minimum voltage in a standing wave, with a value of 2.0 meaning only ~10% of the signal is reflected, while 90% is transmitted or received. This efficiency is critical for maintaining signal integrity in marine systems, where long cable runs (between the antenna and onboard receivers) can introduce signal loss. The antenna’s 350 mm RG174 cable is designed to minimize such losses: RG174 is a low-loss coaxial cable with a small diameter, ideal for routing through the tight spaces of a survey vessel. Its shielding protects against electromagnetic interference (EMI) from onboard electronics, such as radar systems or engine controls, ensuring that GNSS signals remain clean and uncorrupted.  

The TNC (Threaded Neill-Concelman) connector enhances the antenna’s reliability in marine environments. TNC connectors feature a threaded coupling mechanism that provides a secure, weather-resistant seal, preventing water ingress and ensuring stable connectivity even in rough seas. Unlike push-on connectors (e.g., BNC), TNC connectors are less prone to accidental disconnection, a critical advantage when the vessel is pitching or rolling. This robust connection ensures uninterrupted data flow between the antenna and the survey receiver, minimizing downtime during time-sensitive operations.