Gea and Gemini are monitoring systems based on GNSS receivers.
They find application in monitoring large structures (bridges, dams, high rise buildings) and landslides.
Depending on the customer needs our systems can be equipped with high performance GNSS receivers achieving sub-millimetric precision or with low cost GNSS receivers still performing good reaching 1mm precision.
Gea and Gemini working principle is based on the data analysis coming from two or more baseline created by GNSS receivers.
A base station is identified and located outside the monitored zone, one or more monitoring stations are installed on the structure of interest.
Stations communicates with each other through radio or wired connection.
A PC Server collects all data coming from the stations and analyze the baselines.
Software can send email or sms alarms based on previous defined trigger events.
How GNSS system accuracy is increased?
This is a typical question, since we are using in the worst case a GNSS receiver with 5m precision, how is it possible to achieve 1 mm precision?
Precision is increased on the server side with specific algorithms which work on the mitigation of the following source of errors:
- Multipath Errors → Reflected GNSS signals which reach antenna by two or more paths.
- Ionospheric and Tropospheric Delays → Due to the signal propagation path.
- Orbital Errors → Slight shifts of the orbits due to the gravitation forces.
- High frequency receiver Errors → Noise introduced by receivers electronics.
Which are the advantages of using a GNSS monitoring system instead of a simple RTK station?
- GNSS errors mitigation and precision (1cm with RTK → submillimetric with GNSS sw)
- Data integrity control
- Multiple nodes handling
Gea : Low Cost, equipped with single frequency GNSS receiver, long range low power radio module and back up battery.
Gemini : High precision (submillimetric) high rate, dual frequency high accuracy receiver, can be either connected with WiFi or LAN cable, baselines can be as long as 100Km.
|Update rate||Up to 50 Hz||Up to 5 Hz|
|GNSS signal||Single or Dual L1/L2||Single frequency L1|
|Baseline||< 100 Km||< 5 Km|
|NTRIP Protocol||Supported||Not supported|
|Global Reference Station||Supported||Not supported|
|Power Consumption||Mains needed||OK with a small photovoltaic panel|
|Comunication||High speed LAN||LoRa Mesh|
|Price||High-priced Solution||Low Price|
* accuracy is measured after 7 days of monitoring