At the core of this antenna’s capability is its broad frequency coverage, encompassing GPS L1/L2, GLONASS G1/G2, Compass (BeiDou) B1/B2/B3, and Galileo E1/L1/E2/E5b/E6 bands. This multi-constellation support is foundational to modern surveying, where access to multiple satellite systems mitigates the risks of signal blockage, atmospheric interference, or satellite outages. For example, in urban canyons where GPS signals may be obstructed by buildings, the antenna’s ability to switch seamlessly to GLONASS or BeiDou signals ensures continuous positioning. Each frequency band serves a specific purpose: L1 (1575.42 MHz) and E1 (1575.42 MHz) are primary civilian bands for general positioning, while L2 (1227.60 MHz) and E5b (1176.45 MHz) offer enhanced precision through dual-frequency measurements that correct for ionospheric delays. The inclusion of BeiDou’s B3 band (1268.52 MHz) is particularly valuable for surveying in the Asia-Pacific region, where BeiDou’s regional constellation provides robust coverage. By supporting these bands, the antenna enables differential GNSS (DGNSS) and real-time kinematic (RTK) surveying techniques, which achieve accuracies of 1–5 centimeters—far beyond the capabilities of single-frequency, single-constellation systems.

The physical dimensions of D146.5mm x 62.5mm reflect a deliberate balance between performance and practicality. Survey antennas must be large enough to accommodate multiple radiating elements—one for each frequency band—while remaining portable enough for field deployment. The 146.5mm diameter provides sufficient surface area for optimizing the radiation pattern, ensuring uniform sensitivity across all tracked frequencies. This size also allows for a robust ground plane, which minimizes interference from nearby objects and ensures that the antenna’s radiation pattern remains stable regardless of its orientation. The 62.5mm height is designed to house internal components such as low-noise amplifiers (LNAs) and bandpass filters without compromising the antenna’s center of gravity—a critical consideration when mounted on survey poles or tripods, where stability directly impacts measurement accuracy. Unlike compact UAV antennas, which prioritize miniaturization, survey antennas leverage their larger size to achieve superior signal-to-noise ratios and phase stability, both of which are essential for high-precision positioning.

An axial ratio of ≤3dB is a hallmark of the antenna’s circular polarization performance, a key factor in maintaining signal integrity from satellites. GNSS signals are circularly polarized, meaning their electric field rotates as they propagate. An antenna with a low axial ratio (ideally 0dB for perfect circular polarization) can efficiently receive these signals regardless of the satellite’s position in the sky. For surveying applications, where satellites may be low on the horizon (especially in mountainous or urban terrain), this is critical. A high axial ratio would cause signal attenuation for low-elevation satellites, reducing the number of usable signals and degrading positioning accuracy. By limiting the axial ratio to ≤3dB, the antenna ensures consistent reception across the entire sky, maximizing the number of tracked satellites and enabling more robust position solutions. This is particularly important for static surveying, where measurements are averaged over minutes or hours—even minor signal losses can accumulate, introducing errors into the final data.

The peak gain of ≥5dBi ensures that weak satellite signals are amplified sufficiently for precise processing. GNSS signals reach the Earth’s surface with power levels as low as -160 dBm, and survey antennas must capture these signals while minimizing noise. A gain of 5dBi provides a significant boost without introducing excessive noise, thanks to the antenna’s integrated LNAs, which typically have noise figures below 1dB. This combination of gain and low noise is especially valuable in challenging environments, such as dense forests or near electromagnetic interference (EMI) sources like power lines. In such scenarios, the antenna’s ability to amplify desired signals while rejecting noise ensures that even faint satellite signals can be used in positioning calculations. For dynamic surveying—such as mapping with a moving vehicle—the high gain helps maintain signal lock during rapid changes in satellite visibility, preventing data gaps that would require time-consuming re-surveys.

The 360° horizontal coverage angle is essential for the antenna’s omnidirectional performance, a requirement for surveying applications where the antenna’s orientation may vary. Unlike directional antennas, which focus reception in a specific direction, survey antennas must track satellites across the entire horizon. This is particularly important for static surveys, where the antenna is mounted on a tripod and left unattended for extended periods—satellites rise and set, and a 360° coverage angle ensures that none are missed. In dynamic applications, such as marine surveying or road mapping, the antenna must maintain coverage as the vehicle turns, pitches, or rolls. The omnidirectional pattern also simplifies field setup: surveyors do not need to precisely align the antenna with the sky, reducing setup time and minimizing human error. This feature, combined with the low axial ratio, ensures that the antenna performs consistently regardless of its orientation relative to the satellites.

A phase center error of ≤2mm is perhaps the most critical specification for survey antennas, as it directly impacts positioning accuracy. The phase center is the point within the antenna where the received signal’s phase is measured, and any variation in this point introduces errors into distance calculations from satellites. For surveying applications requiring millimeter-level precision—such as monitoring tectonic plate movement or structural deformation—even a 1mm error can render data useless. The antenna’s design minimizes phase center variation across frequencies and angles, ensuring that measurements are consistent regardless of which satellite signals are used. This stability is achieved through careful optimization of the radiating elements and feed networks, as well as rigorous calibration during manufacturing. Unlike consumer-grade antennas, which may have phase center errors of several centimeters, this antenna’s 2mm tolerance enables it to meet the stringent requirements of geodetic surveys and engineering projects.