The Koden GPS-21 is a compact, high-sensitivity “Smart Antenna” sensor. It is an all-in-one GNSS receiver and antenna unit designed to provide precise positioning data to onboard marine electronics, such as chart plotters, echo sounders, and radar systems, without requiring a separate processor or display unit.

The GPS-21 is engineered for reliable performance in harsh marine environments. It acts as a pure “data talker,” converting satellite signals into standard NMEA 0183 sentences, which are then transmitted directly to your navigation equipment.

Key Features

• Multi-Satellite Reception: Provides fast and accurate positioning by tracking multiple satellites simultaneously (supports GPS, SBAS, and QZSS/Michibiki).

• Compact & Integrated: Combines the antenna and receiver into a single, small housing, making it ideal for vessels where space is at a premium.

• High Sensitivity: Features a highly sensitive receiver ($-168$ dBm) to maintain a consistent “fix” even in challenging conditions.

• Standardized Data: Outputs data in standard NMEA 0183 (Ver. 2.3) format, ensuring compatibility with almost all modern and legacy marine display devices.

• Ruggedized: Designed to be waterproof and resistant to the temperature extremes common in marine applications.