BALI: bathymetry made light and simple
A portable kit for hydro surveying
This solution was envisaged as a simple bathymetry kit, compact and performant.
The tool is made of a Single Beam Echo Sounder (SBES) integrated with a GNSS antenna, a battery, and a real-time wireless display software mechanism.
The kit fits in a case and can be mounted on a stick.
0,5 – 200m
By default, the GNSS receiver inside the smart antenna is set to work with GPS+Glonass constellations. It is also possible to extend to Beidou+Galileo.
Receivers are powered by Trimble technology which automatically provides 3 levels of accuracy.
RTK: 1cm-2cm. L-Band (RTX): 4cm -10 cm. SBAS 0.5m-1m.
The NMEA output makes BALI compatible with any bathymetric software such as QINSy, HYPACK, etc. These can be connected either via an ethernet cable or via Wi-Fi. Survey data is stored internally and can be exported in standard file formats (.GPS, .SND, .CSV, .KMZ)
Sounding Rate: 5 times per second.
Depth precision: 99.5%
Power output from transmitter: 100 watts
Beam width: 9° (single freq. SBES) , 26° (dual freq. SBES)
The mono-frequency echo sounder works on 200 KHz and it is generally suitable for depths below 100m. When using the dual-frequency echo sounder, which works both on 200 KHz & 30 KHz frequencies, it is possible to increase the range to 200m limited by ping rate. Minimum depth reading: 0.4m, limited by pulse width.
The rechargeable Nickel–Metal Hydride (NiMH) battery provides autonomy of up to 10 hours. When using a dual-frequency SBES the autonomy is slightly reduced. Another factor affecting the power consumption is, for the RTK system, the type of modem used (GSM or UHF).
These type of battery is safer during transport as compared to Lithium-Ion batteries. An external battery can be connected to increase autonomy.
All antennas, modems, and firmware to make the kit communicate with various types of radio networks are embedded: 3G, UHF (410-470 MHz, ), and Wi-Fi.
Professional tablets and software are not mandatory, as BALI can work completely standalone or using any smartphone with its built-in software connected via Wi-Fi.
Echo Sounder integrated with GNSS
BALI is a bathymetry survey solution, which is extremely accurate. It comes with either a single frequency (SF) or a dual frequency (DF) echosounder which is already integrated with a smart antenna which automatically offers three technological solutions to assure accurate positioning: RTK provides an accuracy of 1-2cm.
L-Band (RTX) accuracy is 4-10cm and is delivered via geostationary satellites. Likewise, SBAS with an accuracy of 0.5-1m.
Both the GNSS accuracy options, constellations, the modems and the options of a single or dual frequency echo sounder can be chosen before or after purchasing the kit. Various alternatives can be studied to make the solution fit the needs of a surveyor.
Professional tablets and software are not mandatory, as BALI can work completely standalone or using any smartphone with its built-in software connected via Wi-Fi. For demanding professionals, the NMEA output makes BALI compatible with any bathymetric software such as QINSy, HYPACK, etc.