“If a worker wants to do his job well, he must first sharpen his tools.” The selection of Beidou equipment is the first step in the application of Beidou technology. If you want to choose a product suitable for geological work needs among the many brands and types of Beidou equipment, you need to have a detailed understanding of its characteristics and usage methods.
According to the function of the equipment, Beidou equipment can first be divided into two categories: command aircraft and mobile terminals.
1. Beidou Command Plane
Beidou Command Plane refers to Beidou equipment with monitoring and command functions. It can monitor and command a certain number of subordinate terminals. It is generally deployed in places with management capabilities. Functional fixed node. According to the number of subordinate users and the difference in configuration, it can generally be divided into two types: central command aircraft and ordinary command aircraft.
(1) Beidou central command user computer
The main function of the Beidou central command user computer is to monitor and manage subordinate users. The central command unit can manage 1,000 subordinate users. The Beidou command aircraft not only has positioning, communication, navigation and timing functions, but also has the functions of command, dispatching, monitoring and broadcasting. Adapt to the use of relatively fixed command nodes. The central command machine comes with its own display screen and operating system, and can be used as an ordinary server.
Figure 6-1 Beidou central command user machine
(1) Command machine configuration and deployment
Beidou central command user machine mainly consists of a host computer , antennas, cables and accessories. As shown in Figure 6-1 and Figure 6-2.
When deploying equipment, attention should be paid to placing the antenna on the top of the building and keeping the antenna open and unobstructed in the south direction in order to receive Beidou signals.
Figure 6-2 Beidou-1 central command user computer deployment diagram
(2) Performance indicators
1) Reception indicators: received signal error Rate ≤ 1 × 10-5 (user machine antenna port input signal power ≥ -157.6dBW);
2) Transmission index: transmit power EIRP value ≤ 19dBW (azimuth angle 0 ~ 360° elevation angle 10° ~ 75°);
3) Number of receiving satellite channels: 6 channels;
4) Equipment zero value: 1ms±10ns.
(3) Functional indicators
1) Positioning function: Positioning accuracy: 20m (1σ) (areas with standard school stations); 100m (1σ) (areas without standard school stations) ;
2) Short message communication function;
3) Navigation function;
4) Command function: The number of subordinate users can be monitored and commanded at the same time ≤ 1,000.
(2) Beidou ordinary command user machine
The main functional difference between the Beidou ordinary command user machine and the central command machine is the number of monitoring terminals. Ordinary command planes can monitor up to 100 subordinate users. It has positioning, communication, navigation and timing functions, as well as command, dispatch, monitoring and broadcast functions. Ordinary command planes do not have a server on their own and need to be connected to other PCs or servers for use. Therefore, the cost of the whole machine is lower than that of the central command machine (Figure 6-3, Figure 6-4).
Figure 6-3 Deployment diagram of Beidou-1 ordinary command user computer
(1) Product features
1) Adopts "One Line Communication" patented technology , that is, two-way transmission of three signals, Beidou transceiver signals and power signals, is realized through a radio frequency coaxial cable. This facilitates the connection between the antenna and the host, making it more convenient and reliable for users to use.
2) Support RS232 interface.
(2) Performance indicators
1) Reception indicators: received signal bit error rate ≤l×10-5 (user machine antenna port input signal power ≥-157.6dBW):< /p>
2) Transmission index: transmit power EIRP value ≤19dBW (azimuth angle 0~360. elevation angle 10°~75°);
3) Number of receiving satellite channels: 6 channels:
4) Equipment zero value: 1ms±10ns.
(3) Functional indicators
1) Positioning function: Positioning accuracy: 20m (1σ) (areas with standard school stations); 100m (1σ) (areas without standard school stations) ;
2) Short message communication function;
3) Dynamic networking function: Flexible dynamic networking can be carried out according to user needs to monitor and receive information from subordinate users.
Figure 6.4 Beidou ordinary command user machine
(3) Selection and configuration of Beidou command machine
Beidou command machine can enable real-time control of command nodes The dynamic situation of subordinate terminals is monitored, security guaranteed and information services are pushed to them. The specific choice of central or ordinary command aircraft must be comprehensively considered based on factors such as the size of the command node and funding costs. For fixed nodes at the level of geological survey bureaus or geological survey centers, due to the large number of subordinate users, a central command unit can be considered, or even multiple units connected in parallel; for provincial geological survey institutes or field station nodes, due to their scale They are smaller and some need to be dismantled and moved frequently, so it is more appropriate to choose an ordinary command plane.
When assembling the Beidou command plane, attention should be paid to fixing the antenna in an open area in the south direction to ensure smooth reception of Beidou signals.
2. Beidou Mobile Terminal
Beidou Mobile Terminal is used to move individual soldier nodes, including personnel, vehicles and large equipment. As Beidou technology matures, the emergence of Beidou second-generation chip-level products has further promoted the diversification and miniaturization of Beidou terminals. According to the difference in terminal usage, it can be divided into vehicle-mounted terminals, handheld integrated terminals and Bluetooth split terminals. How to choose a Beidou terminal suitable for field work is the key to the promotion and application of Beidou technology.
(1) Beidou vehicle-mounted user terminal
Beidou vehicle-mounted user terminal can be divided into embedded Beidou vehicle-mounted user terminal and separate Beidou vehicle-mounted user terminal according to the assembly method. The embedded Beidou vehicle-mounted user terminal infiltrates the display and control terminal into the vehicle body control panel. It generally uses a hand-touch display. Users can control Beidou-related functions through the touch screen, and the device will automatically start up as the vehicle starts. The display terminal of the separate Beidou vehicle-mounted user computer is not associated with the vehicle body. The user controls Beidou functions through the operating handle. Generally, the display screen is relatively small, and the vehicle needs to provide power for the handle and antenna through the on-board power supply. Each time you start the vehicle, you need to manually restart the joystick control.
Beidou vehicle-mounted user terminals can be installed on a variety of vehicles for use. It not only has functions such as Beidou positioning, communication, navigation and timing, but also has GPS navigation and positioning, as well as receiving differential information broadcast by the China Satellite Navigation Enhancement System, realizing differential GPS navigation and positioning and other working modes, and can provide users with manual setting of working modes and editing work Mode switching strategy function.
Beidou vehicle-mounted user terminal is mainly composed of an all-in-one machine, cables, lithium batteries, operating handles and accessories (Figure 6-5).
(2) Beidou handheld integrated terminal
Beidou handheld user terminal combines Beidou navigation communication and GPS, and has its own display screen and operating system, which is easy to carry and easy to carry. Operation can realize Beidou positioning, communication and navigation functions, and is suitable for use by individual soldiers in the field.
Beidou equipment manufacturers design different types of terminals according to different user needs and occasions. In terms of operating systems, there are both the traditional W indows CE and the currently popular Android system: in terms of appearance design, there are both industrial-grade three-proof designs suitable for the wild and thin and light designs suitable for commercial use; in terms of usage, there is both integration and It has a high integrated design and also has a detachable split design. Here are several common Beidou handheld terminals.
(1) "Beidou-1"/GPS dual-mode handheld user terminal
The "Beidou-1" handheld user terminal is a type of user terminal of the "Beidou-1" system , it combines Beidou-1 with /GPS functions and uses the Windows CE operating system, which can meet the positioning communication needs of individual soldiers when used handheld. The antenna, radio frequency unit and signal processing motherboard are integrated into one unit. The host computer contains a display touch screen and a button keyboard, and also integrates an external data interface and a power supply interface (Figure 6-6). The user machine is powered by a battery, completes information input through a stylus or keyboard, and completes various applications of the user machine through human-computer interaction software installed on the handheld machine. The dual-model user machine has Beidou positioning, GPS positioning and navigation, and can receive differential information broadcast by the China Satellite Navigation Enhancement System to realize differential GPS navigation and positioning and other working modes.
Figure 6-5 Beidou vehicle-mounted dual-model user terminal
Figure 6-6 "Beidou-1" handheld integrated terminal
(2) Three defenses Beidou second-generation handheld phone
The machine adopts an industrial-grade three-proof design and integrates Beidou second-generation navigation and communication, GPS, Bluetooth, Wi-fi, 3G and other technologies. It is equipped with Android 4.0 operating system and integrates High degree of accuracy and good scalability (Figure 6-7).
Figure 6-7 Three-proof Beidou second-generation handheld machine
(3) Detachable Beidou second-generation handheld machine
This machine adopts a flexible and removable Detachable design, its base can be used for Beidou to send Beidou text messages. The host terminal is equivalent to a mobile phone, with Beidou second-generation positioning, GPS and 3G communication functions. Normally, the host computer can be used alone under the condition of mobile phone network coverage. When entering the wild environment without network, the base can be temporarily assembled to achieve Beidou communication (Figure 6-8).
Figure 6-8 Detachable Beidou second-generation handheld device
(3) Beidou Bluetooth split terminal
Beidou Bluetooth split terminal is a This kind of Beidou data access module that runs independently can be used with various display and control terminals through Bluetooth function. It is flexible, convenient, and easy to use. Because the device is compact and portable, it can be used in conjunction with existing digital geological survey field data collection equipment (Figure 6-9).
Figure 6-9 Beidou Bluetooth split terminal used in conjunction with the display control terminal
In addition to the basic Beidou functions of positioning and communication, the terminal also has the following special functions:< /p>
1) The combined use of "Beidou-1" positioning communication and GPS: Adopting Beidou and GPS dual-mode integration technology, it can use Beidou satellite positioning and GPS positioning. In the absence of a display terminal, positioning information can also be automatically sent back to command aircraft at different levels according to frequency.
2) SMS caching function: When the terminal is powered on but not connected to the handheld computer, the received text messages (up to 20 messages) will be stored in the internal cache and will be stored when connected to the handheld computer. The cached text messages are "spit" out together.
3) One-click "safety alarm" and distress alarm functions: Provides two shortcut buttons for "safety" and "danger", and supports users to set the sending address and text message content of the two shortcut keys through the software , realizing one-touch safety alarm or distress alarm function.
4) One-click offline SMS query: Provides a shortcut button for offline SMS query (that is, when the terminal is turned off or fails to receive SMS messages when the signal is poor). When the terminal is powered off or fails to receive text messages when the signal is poor, when there is signal, all offline text messages can be queried at the satellite terminal to ensure that text messages are not missed.
(4) Selection of Beidou mobile terminals
Different Beidou devices all have positioning and communication functions in terms of basic functions, but different devices have different application modes and suitable user groups. . Users should equip appropriate Beidou mobile equipment according to their own needs for field use.
The selection of Beidou vehicle-mounted user terminals should be comprehensively considered based on the workload of vehicle modification and user needs, because embedded vehicle-mounted Beidou terminals are easy to operate, but require modification of the vehicle body and technical requirements for assembly. Relatively high, and later maintenance is more difficult. Therefore, it is suitable for the configuration selection of newly purchased vehicles. Before the vehicle is delivered from the factory, through consultation with the vehicle manufacturer, the vehicle-mounted Beidou terminal is embedded into the vehicle's operation panel. It is not only beautiful and easy to operate, but also relatively fixed and difficult to damage. Compared with the embedded vehicle-mounted Beidou user computer, the separate vehicle-mounted Beidou terminal has lower technical requirements for assembly, requires less changes to the vehicle, is easy to disassemble, and has low technical requirements for post-maintenance, making it more suitable for assembly of existing vehicles.
For the selection of user terminals, the appropriate terminal equipment should be determined based on the analysis of the user's existing equipment and equipment, the user's application purposes, and the advantages and disadvantages of the equipment. For field projects that have already carried out digital mapping work, since they are already equipped with certain devices such as handheld computers, they only need to configure the Beidou Bluetooth split terminal to meet the needs of Beidou communications, positioning services and field digital geological surveys. And can effectively control costs. For project teams that have not yet carried out digital mapping or do not need to collect field data, and use Beidou equipment only for communication and security, they should be equipped with Beidou handheld integrated terminals.
Because the Beidou Bluetooth split terminal uses Bluetooth connection, when Bluetooth is disconnected for some reason, the real-time nature of the information cannot be guaranteed, and there are certain security risks. With the development of the digital geological survey system based on the Android system, users can also choose the detachable Beidou second-generation handheld device based on the Android system when purchasing a new digital geological survey equipment terminal. When the user performs digital geological survey work, he or she can The terminal is detached and operated with the user. When users need it as a security terminal, it can be used in an integrated manner to avoid the instability of Bluetooth transmission.