Continuously Operating Reference Stations (CORS):

The reference stations are equipped with GNSS receivers and Choke-ring antennas to collect GNSS raw data (Carrier Phase and Pseudorange Code).

Uninterruptible Power Supply (UPS) are installed at each of the CORS to ensure the GNSS receivers can work continuously even with power failure.

The routers will transfer the GNSS data, meteorological observation and tilt data to the SatRef Data Centre.

SatRef Data Centre:

The Data Centre is used to process data collected from CORS in a high availability infrastructure and provide services to users via internet.

SatRef Control Centre:

The Control Centre is used to monitor the operation of the whole SatRef system, the GNSS data status, quantitative and qualitative control of both products and services, etc.

There are 19 CORS in Hong Kong. Ten stations are built at hilltop with a 5m high pillar and fenced to avoid disturbance. The other nine stations are installed on building rooftop. The separation of the reference stations is about 10 to 15km. This is to provide at least two stations within 10km for users in most of the areas in Hong Kong.

Structure of CORS:

Antenna: Receive GNSS signals

Meteorological Sensor: Receive the meteorological data (temperature, pressure and humidity) for atmospheric analysis.

Tilt Sensor: Monitor the verticality of the 5m pillar and detect abnormal shift of the reference station.

Remark: There is no Tilt Sensor for the roof-top station (HKPC, HKSC, T430, HKTK, HKKS, HKQT, HKCL & HKLM).