NAV-Agro RTK navigation receiver: Description, operation and technical characteristics (part one)

This operating manual applies to the navigation receiver NAV-Agro RTK (hereinafter referred to as the receiver).

ROVER

 

BASE

Description and work

The NAV-Agro RTK navigation receiver, depending on the software settings, can work as an RTK Rover or as an RTK Base Station
1) mode No. 1 - RTK Rover (rover), this is a mobile navigation receiver that in offline mode determines coordinates based on free satellite navigation signals, and in RTK mode uses corrective information from the RTK base station to obtain coordinates with centimeter accuracy. Corrective information in the RTK Rover can be transmitted from the RTK base station via the Internet or via the LoRa radio channel (LoRa stands for Long Range Radio (up to 8 km), LoRa technology is a new wireless protocol designed specifically for communication on long distances and low-power communication).
2) mode #2 - RTK Base Station (base station), this is a stationary navigation receiver that produces RTK correction information and transmits it to RTK rovers.

This manual contains important information about setting up the rover and using it for its intended purpose. Read the manual carefully before turning on and using the rover. For correct use, it is necessary to follow the instructions and directions given in this manual.

A rover is a navigational device used in agricultural machinery to perform precision operations such as sowing, chemical treatment, weeding, harvesting, and more. It can also be used in construction and other industries where precise positioning is required (see Figure 1).

Figure 1 - Where RTK is used, in which industries centimeter-accurate coordinates are needed

Purpose

The rover is designed for automatic, continuous determination of location, speed and time coordinates, in RTK mode and autonomous mode, using GPS, Galileo, BeiDou SNS radio signals and providing navigation data to users.

Main tasks by appointment

The rover provides solutions to the following tasks in continuous mode of operation:

• receipt and processing of SNS GPS signals in the L1, L2 range, Galileo in the E1, E5b range, BeiDou in the B1I, B2I range;
• automatic continuous generation of time-bound navigation parameters - values of current coordinates, speed vector, altitude, date;
• issuance of navigation information to the consumer via the RS-232 and Bluetooth interface;
• obtaining corrective information in accordance with the RTCM SC-104 standard and using it to determine navigation parameters with centimeter accuracy in RTK mode. Corrective information in the RTK Rover from the RTK base station can be transmitted over the Internet or over the LoRa radio channel.

Technical characteristics

Received signals:

• • GPS L1 C/A, L2C;
  • Galileo E1 B/C, E5b;
  • BeiDou B1I, B2I.

The number of reception channels and interfaces for issuing and receiving data

• Total number of reception channels from NCA – 184.
• Interfaces - bluetooth 2 channels (NMEA01, RTCM_Conf01) and RS232.

Accuracy of determination of navigation parameters

The root mean square error of determinations of the current values of the navigation parameters, no more than:

• planned location coordinates in offline mode, m 1.5;
• height in offline mode, m 2.0;
• planned location coordinates in RTK mode, m 0.03m + 0.001m*L;
• heights in RTK mode, m 0.05m + 0.001m*L,

where L – distance to the base station, km.

Definition of navigation parameters in RTK mode is provided with the presence of corrective information in accordance with the RTCM SC-104 v3.3 standard.

The specified accuracy of determining the navigation parameters is ensured with normal operation of the SNS, values of the spatial geometric factor HDOP no more than 2, shadowing of the rover by surrounding objects no more than 5° above the horizon and at a distance to the base station of no more than 25 km (for RTK mode).

Time characteristics

Time of obtaining the first solution of coordinates, time and altitude in offline mode – no more than 60 s.

The time of obtaining the solution of coordinates, time and height in the RTK mode, in the presence of the solution in the offline mode and after receiving the corrective information according to the standard RTCM SC-104 – no more than 180 s.

Rate of issuing navigation parameters in RTK mode based on GPS+ Galileo+ BeiDou signals - up to 5 Hz.

Power supply

The rover is powered by an external direct current source with a voltage from 5 to 16 V.

The power consumption of the rover is no more than 2.5 W. It is allowed to power the rover from USB with an output power of 10 W (DC 5V, 2A).

Typical RTK base station power consumption is no more than 4.0 W. It is allowed to power the rover from USB that supports an output power of 10 W (DC 5 V, 2 A).

External influences, mass, dimensions

Operating temperature range from minus 20 to 70 °C;

Mass, no more 1.2 kg;

Overall dimensions Ø152×108 mm

Assembly

Table 1.4

Pos. No	Name	Tag	Quantity
	Basic configuration of NAV-Agro RTK navigation Receiver
1	NAV-Agro RTK navigation receiver	NAV-Agro RTK	1 pc.
2	Power cord	Extension cable	1 pc.
3	LoRa antenna for rover	Ant-LoRa-Rover	1 pc.
4	LoRa antenna with 3 m cable, (the antenna is intended for use in base station mode, or for improved reception/transmission in rover mode)	Ant-LoRa3m-Base	1 pc.
5	Instructions for operation	NAV-Agro RTK RE	1 copy
6	Label	NAV-Agro RTK ET	1 copy
7	Packaging	-	1 k-t.
8	Android program for NAV-Agro RTK navigation receiver settings	RTK-Config	1 copy (Appendix D)
9	Android program for agricultural navigation and transfer of RTK corrections to RTK rover	SmiLab-Agro	1 copy
Additional complete set for NAV-Agro RTK navigation receiver (the composition of additional complete sets is agreed upon when ordering)
10	Tablet with or without SIM card support sim cards	(negotiated when ordering)	-
11	Package of subscriber RTK services (for access to the Internet network of RTK correction information)	(negotiated when ordering)	-
12	USB power cable	(negotiated when ordering)	1 pc.
13	RS232 cable and power supply 10 m (required when installing a stationary RTK base station in the customer's premises)	Vin-RS232 cable (negotiated when ordering)	1 pc.
14	Power supply unit from the 220 V network	(negotiated when ordering)	1 pc.
15	Tripod (for installing and moving the base station)	(negotiated when ordering)	1 pc.
16	Additional paid agricultural software	(negotiated when ordering)	-
17	Section control units are automatic or manual	(negotiated when ordering)	-
18	Industrial metal tablet holder	(negotiated when ordering)	1 pc.

 

1) NAV-Agro RTK navigation receiver

3) LoRa antenna (intended for rover)

 

4) LoRa antenna with a 3 m cable, with a remote pole (the antenna is intended for use in base station mode, or for improved reception / transmission in rover mode)

15) Tripod (for installing and moving the base station)

16) Additional paid agricultural software with functions of differentiated application (possibility of working with application cards, application rate is supported automatically depending on the information in the application card).

15) Section control units are automatic or manual

16) Industrial metal tablet holder

Figure 1.4 Photo of the component parts of the NAV-Agro RTK navigation receiver

 

 

To receive corrective RTK information by the rover via the Bluetooth channel, you need a tablet (not included in the basic delivery) with an installed and configured program NTRIP Client. The tablet is provided by the user or supplied under separate conditions.

To receive corrective RTK information by the rover via the LoRa radio channel, one additional NAV-Agro RTK navigation receiver is required, which will be configured in the RTK Base Station mode and will generate corrective information and transmit it via the LoRa radio channel to the rover (see point 1).

 

Rover device and operation

Principle of action

The work of the rover is based on the use of GNSS satellite navigation signals.

Principle of action – the rover is in autonomous mode, immediately after turning on the power it receives signals from GNSS navigation satellites and determines its current coordinates, speed and time.

In the RTK mode of operation, the rover receives corrective information (RTK corrections) from the base station via the Internet or the LoRa radio channel, which refine the rover's coordinates to centimeter accuracy (see Figure 1.5.1).

Figure 1.5.1

How RTK technology works.

Real Time Kinematic (RTK) - a method of receiving rover coordinates with centimeter accuracy using satellite navigation by obtaining and using corrections from a base station or network of base stations.

To transmit corrections (corrective information) from the base station to the rover, the Internet or the LoRa radio channel is used. RTK base station, installed at a known point of location, continuously observes satellites and calculates corrections to their actual position. Corrections every second are sent via the Internet, via NTRIP-server to the NTRIP-caster, and then to the consumer's rover, or immediately directly via the LoRa radio channel.

Definition and explanation:

RTK base station — receiver navigation, operating in the "base" mode; and generates corrective information in RTCM;

format

NTRIP-server (server) — a computer with software that delivers packets of information from a base station to NTRIP-caster (caster);

NTRIP-caster (caster) — a system component that is responsible for packet switching between the base station and the rovers. This is a computer with software that supports HTTP message in "request/response" mode;

NTRIP-client (client) — a program on a tablet for receiving packages of corrective information from the caster and transfer to the rover.

The operation of the rover during the transmission of corrective information via the Internet to the Android device and further via bluetooth to the rover, from the GNSS network

This item describes the operation of the equipment set, which consists of the rover itself and the tablet with NTRIP Client installed. A SIM card of a mobile operator with paid mobile Internet services must be installed in the tablet.

The rover connection diagram when transmitting corrective information via the Internet from the GNSS network is shown in Figure 1.5.2.

After connecting to a power source, the rover offline searches for and receives navigation signals from satellites, and calculates coordinates and speeds with fairly high accuracy. For the rover to transition from autonomous mode to RTK mode (determination of coordinates with an accuracy of +/- 2 cm), the rover must start receiving corrective information.

The navigation receiver contains two Bluetooth modules. One Bluetooth module, conditionally "outgoing" which has the name "NMEA01", intended for issuing navigational NMEA messages with coordinates according to the NMEA-0183 standard to consumer equipment. The navigation information issued by this Bluetooth module is duplicated via the RS-232 interface through the power cable and interfaces.

The second Bluetooth module, conditionally "input" which has the name "RTCM_Conf01", intended for receiving corrective RTCM information from the tablet, or for setting up the navigation NAV-Agro RTK receiver using the RTK-Config android application (see Appendix G).

The tablet ensures receiving corrective information from the base station from the Internet and transmitting it to the rover using the Bluetooth interface named "RTCM_Conf01". If the user does not have his own RTK base station, to work in RTK mode with centimeter accuracy of coordinates, the user needs to obtain appropriate access from existing operators of the geodetic GNSS network, which provide RTK correction services, paid or free.

Figure 1.5.2

 

After gaining access, it is necessary to enter the NTRIP connection parameters, which are specified in the accompanying information for each base station, once into the NTRIP Client program installed on the tablet.

The results of the calculation of the navigation parameters of the coordinates are issued to the consumer via Bluetooth, which has the name "NMEA01" and/or RS-232 interface in the form of NMEA-0183 protocol messages and displayed on the tablet display.

Rover factory settings and NMEA-0183 message composition are listed in Appendix B.

 

The operation of the rover during the transmission of corrective information via the Internet to the Android device and further via bluetooth to the rover, from its own RTK base station

Important: An additional NAV-Agro RTK navigation receiver can be used as a base station. It turns into an RTK base station by reconfiguring in the RTK-Config android program (see Appendix D). Reconfiguration of the equipment in the RTK-Config android program can be carried out by the user himself.

The rover connection diagram when transmitting corrective information via the Internet from its own RTK base station is shown in Figure 1.5.3

 

Figure 1.5.3

A separate base station is installed in an open area so that the sky in the upper hemisphere can be seen, for example, on the roof of an administrative building. The base station is connected to a computer with a cable up to 15 m long, the computer is installed in a room with a stationary 220 V power supply and high-quality Internet. It is recommended to provide power to the base station with a separate AC/DC power supply unit with an output voltage of 9 V or 12 V, with an output current of at least 2 A. The base station produces corrections according to the RTCM 3.3 standard and transmits them via a cable using the RS-232 protocol to a computer, to the NTRIP server program, and further, via the Internet, to the caster (SO NTRIP caster) with with an interval of 1 sec. NTRIP caster is a source of corrections for RTK rovers.

The base station via the Internet provides RTK corrections to rovers within a radius of up to 25 km from the location of the installation of the base station itself.

A cable up to 15 meters long is not included in the standard delivery package, it must be ordered separately.

The operation of the rover during the transmission of corrective information via the LoRa radio channel from its own RTK base station

Important: An additional NAV-Agro RTK navigation receiver can be used as a base station. It turns into an RTK base station by reconfiguring in the RTK-Config android program (see Appendix D). Reconfiguration of the equipment in the RTK-Config android program can be carried out by the user himself.

The rover connection diagram when transmitting corrective information via the LoRa radio channel from its own RTK base station is shown in Figure 1.5.4

Figure 1.5.4

 

A separate RTK base station is installed in an open location so that the sky in the upper hemisphere can be seen, for example at the edge of a field to be cultivated. After powering on and simple setup (see Appendix D ) RTK base station will start producing corrections according to the RTCM 3.3 standard and transmitting them over the LoRa radio channel directly to the rover (or rovers) with with an interval of 1 sec.

The base station of the LoRa radio channel provides RTK corrections to rovers in the line-of-sight area, within a radius of up to 8 km from the location of the base station itself. To improve the quality of data transmission over the LoRa radio channel, it is recommended to raise the LoRa antenna with a 3 m cable as high as possible.

Using the system in agriculture

Figure 1.5.5

The rover is mounted on a tractor. The rover receives corrective information, and via Bluetooth, which has the name "NMEA01" coordinate data from the rover are transferred to the tablet, to the consumer's android program, for example, the SmiLab-Agro program (see Figure 1.5.5 on the image in the lower screen of the tablet) or a similar program.

Marking

The NAV-Agro RTK navigation receiver has markings that include the name of the device, telephone numbers for consultation, the factory number "RTK01", and the names of two Bluetooth "NMEA01" and "RTCM_Conf01" (where "01" is the factory serial number, which is different for each product and corresponding Bluetooth names, see Figure 1.8.2). Marking signs are pasted on the visible part of the receiver body.

Packaging

The packaging provides protection of the NAV-Agro RTK navigation receiver from climatic influences and mechanical damage during transportation, loading and unloading operations and storage. The package includes: packing cardboard bag, box, polyethylene covers.

When unpacking and unpacking, it is recommended to take measures to preserve the packaging for reuse.

Description and operation of constituent parts

Navigation receiver

The NAV-Agro RTK navigation receiver with RTK support is intended for:

• receipt and processing of information of NCA SNS GPS, Galileo and BeiDou;
• reception and processing of RTK correction information RTCM 3.0 via LoRa radio channel or via Bluetooth with the name “RTCM_Config01” (from specialized programs such as NTRIP Client);
• determination of coordinates, speed, direction of movement and height;
• issuance of navigation information to the consumer via the RS-232 interface in accordance with the NMEA-0183 standard and via Bluetooth with the name “NMEA01” .

The block diagram of the NAV-Agro RTK receiver is shown in Figure 1.8

Figure 1.8

 

The receiver is powered by an external direct current source with a voltage of 5 to 16 V.

Constructively, the navigation receiver is a protected round-shaped case made of strong plastic, in which the printed circuit board with the controller of the navigation receiver is installed, L1, L2 antenna, LoRa module, two Bluetooth modules, secondary power source. To install the navigation receiver on the object, its design provides a stand with a magnetic attachment. The appearance of the receiver is shown in Figure 1.8.1.

Figure 1.8.1

Composition of the lower part of the NAV-Agro RTK navigation receiver (indicator button, HF SMA Lora socket, output cable, signs, internal sound indication)

On the lower part of the receiver body are (see Figure 1.8.2):

Figure 1.8.2

Exit cable with a 4-pin plug connector (assignment of contacts No. 1 +Vin (+5…16 V), No. 2 TxRS232, No. 3 RxRS232, No. 4 GND, intended for issuing navigation information and supplying power supply voltage;

HF SMA LoRa connector plug for connecting a pin antenna for receiving the transmission of correction information via the LoRa radio channel
IMPORTANT: When transmitting correction information via the LoRa radio channel, to the HF SMA LoRa The LoRa pin antenna must be connected to the connector (otherwise, without an antenna, the LoRa module inside the receiver may fail).

The button with the indicator has the following flashing modes:

• 1 Hz blinking - no solution;
• 2 Hz flashing (repetition interval 1 second) - 3D solution (coordinates obtained in offline mode by free satellite signals);
• 3 Hz flashing (repetition interval 1 second) - FLOAT solution (coordinates are obtained offline from free satellite signals and corrective information is obtained);
• The indicator lights up constantly - RTK Fix mode (coordinates are obtained in RTK mode with an accuracy of +/- 2 cm).

Pressing the button with the indicator performs the following functions (number-number of presses, in response to the press, confirmation sound signals of the buzzer sound):

a) 1 - request the mode (answer 3 beeps of the buzzer - rover or 4 beeps of the buzzer - base station);

b) 2 - set current coordinates as reference for the base station (1 long buzzer signal - set, 2 short buzzer signals - not set);

c) 3 - switch to rover mode (response to 3 beeps of the buzzer);

d) 4 - switch to base mode (response to 4 beeps of the buzzer);

e) 5 - ask if there is a navigation solution (1 long - yes, 2 short - no);

f) 6 - reset the almanac (response to 6 signals);

c) pressing the button for 5 seconds - software restart of the central processor.

In the middle of the NAV-Agro RTK navigation receiver there is a sound buzzer whose audio signal values are described in clause 1.8.2.4. Also, the buzzer emits sound signals when receiving a fixed RTK solution with an accuracy of +/- 2 cm, these are two short signals, and when the loss of a fixed RTK solution is one long signal.

Signs with telephone numbers for consultation, marking, device name, factory number "RTK01" and Bluetooth names "NMEA01" and "RTCM_Conf01" (where "01" is the factory serial number, which is different for each product and corresponding Bluetooth names, see Figure 1.8.2);

Magnetic stand for fixing the receiver on metal surfaces, there is a protective film on the magnet.

Dimensions of NAV-Agro RTK navigation receiver

The overall dimensions of the NAV-Agro RTK navigation receiver are given in Appendix B. The weight of the receiver is no more than 0.8 kg.

Tablet

The tablet with the NTRIP Client program installed is designed to connect to the Internet, receive corrective information from the base station, and transmit it to the rover using the Bluetooth interface named "RTCM_Conf01".

Other application programs can be installed on the same tablet, such as the SmiLab-Agro parallel driving program (see Figure 1.5.5). The navigation data received by the rover is transmitted from the rover to the tablet using a Bluetooth interface named "NMEA01".

External the appearance of a typical tablet is shown in Figure 1.8.4.

; Figure 1.8.4

Recommended specifications of a typical tablet

Characteristics	Meaning
Diagonal screen size	8"
Processor	2 GHz
Random memory	2 GB
Wireless capabilities	Bluetooth, Wi-Fi
Operating system	no lower than Android 4.4
Screen resolution	1024x600
With‘connectors	USB Type-C
Battery	5100 mA·hours
Terms of use:
- supply voltage, V	5
- operating temperature range, °С	from +5 to +35

 

The above specifications of the tablet correspond to the Samsung Galaxy Tab A 7.0 model". It is possible to use a tablet with the specifications "no worse" than the ones listed.

When using the rover on a vehicle, the tablet is attached to the glass of the cabin using a car holder in a convenient, dry and clean place and is connected via a charger that is inserted into the cigarette lighter socket.

!!!! The tablet does not have climate protection and must be installed in the cabin.

Intended use

Operational restrictions

1. Staff who have the skills to work on a computer with the Windows OS and the skills to work with a tablet with the Android OS are allowed to work with the rover.
2. To ensure reliable determination of navigation parameters, the receiver place in a place that provides a maximum view of the upper hemisphere of the sky. Permissible shading of the receiver – no more than 5° above the horizon.
3. Drops in supply voltage, for example, when starting engines with a starter with weak batteries, can lead to a reboot or failure of the receiver.

!!! When placing the receiver in rooms, tunnels, near buildings and high objects Determination of navigation parameters with given technical characteristics is NOT GUARANTEED.

Preparation of NAV-Agro RTK navigation receiver for use

After purchasing the NAV-Agro RTK navigation receiver, the consumer must independently perform the following steps to put it into operation:

• conduct an external inspection of the package for mechanical damage;
• unpack and unpack the component parts of the receiver in accordance with clause 3.4.1, it is recommended to take measures to preserve the packaging for reuse (during conservation);
• check the completeness of the receiver according to the NAV-Agro RTK ET label;
• conduct an external inspection of the component parts of the receiver for the absence of mechanical damage and the integrity of the seals. If there is mechanical damage or damage to the seals, return the rover to the manufacturer;
• if you plan to use the NAV-Agro RTK receiver as a rover with the reception of corrective information via the Internet from the GNSS network, you need to purchase a SIM card of a mobile operator, based on ensuring the coverage area of the territory where the receiver will be used. You also need to purchase a package of access services to corrective information from one of the GNSS networks;
• set up Bluetooth communication between the lancet and the NAV-Agro RTK receiver (in the middle of the receiver there are two Bluetooth modules with the names «RTCM_Conf01» and «NMEA01»). To do this, on the tablet in the "Settings" menu; Bluetooth» start searching for available bluetooth devices. From the received list select the name of the first "incoming" of the Bluetooth module (corresponds to the individual code of the rover, which is indicated on the sign below the receiver and has the form «RTCM_Conf01»). At the request to enter the password, enter - 1234.
  Then on the tablet in the "Settings" menu — Bluetooth» start searching for available bluetooth devices. From the received list select the name of the second "outgoing" of the Bluetooth module (corresponds to the individual code of the rover, which is indicated on the nameplate below the receiver and has the form «NMEA01»). When asked to enter a password, enter - 1234.
• perform rover performance check in accordance with clauses 2.3-2.5;

Intended use of NAV-Agro RTK navigation receiver, when transmitting corrective information from own RTK base station via LoRa radio channel

1. The simplest, most reliable and cheapest scheme for transmitting corrective information from the base to the rover is its transmission via the LoRa radio channel, with such a scheme you do not need access to the Internet, you do not need to pay regular subscription fees for mobile Internet and access to corrective information, which are also much simpler settings are required to get started. But for this scheme, you need to purchase at least two NAV-Agro RTK navigation receivers, one of which will be used as a base station, and the second as a rover.
2. In order to check the performance, you need:

• Install two NAV-Agro RTK navigation receivers (the first NAV-Agro RTK receiver will work as a base after settings, the second as a rover) on an open site in the zone of safe reception of SNS satellite signals in accordance with clause 2.1.2;
>

Setting the NAV-Agro RTK navigation receiver into base station mode with the transmission of corrective information via the LoRa radio channel

In order to generate and issue corrective information to the base station, it is necessary to enter the reference coordinates of its location, this can be implemented in three ways:

Method No. 1 - setting the operation of the base station with the button-indicator (with the transmission of corrective information via the LoRa radio channel)

• Install the receiver in an open place, apply power to the NAV-Agro RTK navigation receiver and reconfigure it to Rover mode, for this, press the indicator button on the receiver three times, in response the buzzer signal should sound three times.
• Wait until the rover receives a navigation solution (the indicator on the button will blink twice per second), set the current coordinates received by the rover as a reference for the base station - for this, press the indicator button twice, a single long buzzer signal should sound in response (if the signal will sound twice, this means that the reference coordinates have not been set, in which case you need to try again).
• Reset the receiver to Base mode (base station), for this, press the indicator button on the receiver four times, the buzzer signal should sound four times in response.

Notes:
1) Sound indication must be turned on (see Appendix D).
2) In order for the rovers to receive RTCM messages from the base station, the transmission channel must be correctly selected and configured between them data, channels are configured in the RTK-Config android program, in the "Streams" menu (see Appendix D).

IMPORTANT - after completing the setup of the base station, it is important not to move it from its place. If the base station has been moved, it is necessary to perform its settings again.

Method #2 - setting up the base station in the android program RTK-Config, with determination of reference coordinates by the NAV-Agro RTK receiver (with transmission of corrective information via the LoRa radio channel)

IMPORTANT - after completing the setup of the base station, it is important not to move it from its place. If the base station has been moved, it is necessary to perform its settings again.

• The NAV-Agro RTK navigation receiver itself can be used to determine the reference coordinates of the location of the base station. To do this, install the receiver in an open place, apply power to the NAV-Agro RTK navigation receiver and reconfigure it to Rover mode, for this, press the indicator button on the receiver three times, in response the buzzer signal should sound three times.
• Wait until the rover receives a navigation solution (the indicator on the button will blink twice per second), set the current coordinates received by the rover as reference for the base station, for this, launch the android program RTK-Config, in the « Bluetooth devices» select Bluetooth with the name "RTCM_Conf01" (see Figure 2.3.3.1), after that a connection should be established via Bluetooth, in the window of the RTK-Config icon Bluetooth will change from red to green (see Figure 2.3.3.2).

 

Figure 2.3.3.1	Figure 2.3.3.2

 

• In the android window of the RTK-Config program, click “Position solution data”, after which the page as shown in Figure 2.3.3.3 will open, and click “MAKE REFERENCE COORDINATES”.

Figure 2.3.3.3

• Make sure that the reference coordinates have been sent and installed in the NAV-Agro RTK navigation receiver, for this, in the RTK-Config program, go to the “Base Mode” and make sure that the reference coordinates match those entered in point 2.3.3.1.2.3 (see and compare figures 2.3.3.3 and 2.3.3.4)

Figure 2.3.3.4

Method #3 - setting up the base station in the android program RTK-Config, with manual input of reference coordinates (with transmission of corrective information via the LoRa radio channel)

• If the reference coordinates of the location of the base station are known, they can be entered into the base station manually using the RTK-Config android program, for this, launch the RTK-Config android program, in the "Bluetooth devices" menu; select Bluetooth with the name "RTCM_Conf01" (see Figure 2.3.3.1), after that a connection should be established via Bluetooth, in the window of the RTK-Config icon Bluetooth will change from red to green (see Figure 2.3.3.2).
• Go to “Base Mode”, enter the coordinates manually, and press “APPLY”, (see figure 2.3.3.5).

Figure 2.3.3.5 (Minimum recommended set of RTCM messages)

• Press the indicator button on the receiver four times, in response, a confirmation buzzer signal should sound four times (the receiver will switch to Base mode).

IMPORTANT - after completing the setup of the base station, it is important not to move it from its place. If the base station has been moved, it is necessary to perform its settings again.

Intended use of the NAV-Agro RTK navigation receiver when transmitting corrective information via the Internet from the GNSS network

• The manufacturer of the NAV-Agro RTK navigation receiver for the transmission of corrective information to the receiver via the Internet from the GNSS network recommends using one of the three Android programs at the user's choice - 1) RTK-Config (see clause 2.4.1.10 or Appendix G ), SmiLab-Agro (Appendix Z) or NTRIP-Client (see clause 2.4.1.11)
• Install the navigation receiver on an open site in the zone of safe reception of SNS satellite signals in accordance with clause 2.1.2;
• Connect the receiver according to Appendix A. apply power from a DC 5…16V source. Monitor the presence of power to the receiver on the button indicator (it should glow blue).
• By default, the navigation receiver at the manufacturer's enterprise is set to rover mode, with a channel for receiving corrective RTK information via the Internet to the tablet, and via Bluetooth interface named "RTCM_Conf01" from the tablet to the rover (see item 1.5.2). If the receiver has already been reconfigured, then to work in the mode of receiving corrective information via the Internet from the GNSS network, you need to connect via Bluetooth with the name "RTCM_Conf01" configure the receiver in the RTK-Config program according to figure 2.4.1.0, and click "Apply"

Figure 2.4.1.0

 

• Connect the tablet to the Internet using Wi-Fi or install a SIM card with paid Internet traffic in the tablet.

Note – The SIM card is installed and removed only when the tablet is turned off.

• Turn on the tablet, after which the tablet will automatically enter the operating system startup mode. After the normal completion of the OS startup, the tablet will display the main screen.
• Activate Bluetooth on the tablet and configure communication with the receiver. To do this, on the tablet in the "Settings" menu; Bluetooth» start searching for available bluetooth devices. From the received list select the name of the "outgoing" of the Bluetooth module (corresponds to the individual code of the rover, which is indicated on the nameplate below the receiver and coincides with the factory number of the rover. For example, «NMEA01»). When asked to enter a password, enter - 1234.

Note – The procedure for adding to the list of synchronized devices is performed once when the tablet is connected to the device for the first time.

• Check for NMEA standard notifications – RMC, GGA, GNS, which are transmitted by "outbound" Bluetooth interface why launch a terminal program on the tablet (for example, Serial Bluetooth Terminal v1.4).
• If the customer needs to connect the NAV-Agro RTK navigation receiver to a personal computer (see clause 1.5.2), check the presence of NMEA standard notifications – RMC, GGA, GNS, which are transmitted via the RS232 interface. For this you need connect the "X2" connector power cable and interfaces to the RS232 port of a personal computer using a technological cable (supplied separately by agreement). And run a terminal program (for example U-cenrt) on the PC. PC port speed setting – 115200 bps.
• Set up the connection of the tablet with the receiver through the "input" Bluetooth module. To do this, on the tablet in the "Settings" menu; Bluetooth» start searching for available bluetooth devices. From the received list select name of "incoming" of the Bluetooth module (corresponds to the individual code of the rover, which is indicated on the nameplate below the receiver and has the form «RTCM_Conf01»). When asked to enter a password, enter - 1234.

Option to use the RTK-Config program

In the RTK-Config program according to figure 2.4.1.0.1, go to the NTRIP client menu (1), enter the NTRIP data of the server of the source of correcting RTK information (2), and click "Apply" (3). In the main menu, change the color to the green indicator N (4), in the Position solution data menu, the fixation mode should change from no Fix to Float f then to Fix

Figure 2.4.1.0.1

Usage option for the NTRIP Client program

Start the NTRIP Client program on the tablet (further on in the text – program), for which touch the icon The main program window will open (Fig. 2.4.1.1). Perform program settings, for which touch the icon Next in the main menu (Figure 2.4.1.2 ) touch the item "Receiver Setting"

Figure 2.4.1.1	Figure 2.4.1.2

Note – Detailed settings of the NTRIP-Client program are given in Appendix B.

• In the submenu "Receiver Setting" touch the item "Bluetooth Device" (Figure 2.3.1.3), and in the list that opens, select the name of the rover Bluetooth module for connection (choose the "input" module with the name "RTCM_Conf01").

Figure 2.4.1.3	Figure 2.4.1.4

 

• Return to the main menu of the program (Figure 2.4.1.2) and tap on "NTRIP Setting". In the "NTRIP Setting" submenu (Figure 2.4.1.4), configure the connection to the source of RTK corrections (NTRIP Caster):

Caster IP (Caster IP address)

Note - if you need to take RTCM from your own server configured as described in clause 2.5, then Caster IP can be found out on the website https://www.myip.com/ or any another similar service.

• Caster Port (port Caster);
• Userneme (user name);
• Password (access password);
• Data Stream (mount point).

Note – Based on the needs, the user orders and pays for the services that best suit his work for the most convenient period.

• Return to the main program window (Figure 2.4.1.1) and touch the "Connect" button of the program. In the program window, observe the process of connecting to the receiver (Figure 2.4.1.5).

Figure 2.4.1.5

If the tablet is connected to the receiver and connected to the correction source (NTRIP Caster), the program window displays:

• operation mode (GPS, DGPS, FloatRTK, RTK);
• age of corrections (the time interval between the moments of receipt and formation of corrections at the base station);
• coordinates (latitude, longitude);
• height;

Note – the composition and location of the parameters displayed in the program window can be changed in the "Display Setting" submenu. main menu.

Control the operation of the rover according to the mode of operation of the indicator of corrective information rover (see clause 1.8.2.3 and figure 1.8.2):

• 1 Hz blinking - no solution;
• 2 Hz flashing - 3D solution;
• 3 Hz flashing - FLOAT solution;
• constant indication – in the presence of a fixed RTK solution.
• 2.4.2 The rover is operational if the navigation parameters are displayed on the tablet display in the NTRIP Client program window (Figure 2.4.1.5).
• 2.4.3 If the rover does not work in RTK mode, communication with the receiver, communication with the source of corrections (NTRIPCaster), it is necessary to check the correctness of the Bluetooth interface setting and connection settings to NTRIP Caster. If, after re-checking, the rover's operability is not confirmed, contact the manufacturer (the telephone number for consultation is indicated on the sign below the receiver, Fig. 1.8.2).

To terminate the program touch the button «Disconnect»
(Figure 2.4.1.5) and close the program.

Intended use of NAV-Agro RTK navigation receiver when transmitting corrective information via the Internet from its own RTK base station

To configure the transmission of corrective information via the Internet from your own RTK base station, it is recommended to contact the manufacturer of the navigation receiver (the telephone number for consultation is written on the nameplate at the bottom of the receiver), in general, the following is required for configuration:

• Install the receiver in an open place, apply power to the NAV-Agro RTK navigation receiver and reconfigure it to Rover mode, for this, press the indicator button on the receiver three times, in response the buzzer signal should sound three times.
• Wait until the rover receives a navigation solution (the indicator on the button will blink twice per second), set the current coordinates received by the rover as a reference for the base station, for this, press the indicator button twice, a single long buzzer signal should sound in response (if the signal will sound twice, it means that the reference coordinates have not been set, in which case you need to try again).

Reset the receiver to Base mode (base station), for this, press the indicator button on the receiver four times, the buzzer signal should sound four times in response. You can also reconfigure the receiver to Base mode via Bluetooth with the name "RTCM_Conf01" using the RTK-Config android program (see clause 2.3.3.1 or appendix D).

On a personal computer, perform “port forwarding” (Port Forwarding), Figure 2.5.1.0 shows an example of “port forwarding” on the example of the TP-LINK TL-WR740N router.

Figure 2.5.1.0 - example of “port forwarding” on the example of the TP-LINK TL-WR740N router.

Next, you need to configure RTCM output for BASE mode with NAV-Agro RTK via RS232 port

and install the strsvr.exe program on the PC (from RTKLIB: An Open Source Program Package for GNSS Positioning), and configure it as internet server of the base station (NTRIP Caster), for this you need:

Start the strsvr program on the PC (Fig. 2.5.1.1):

Figure 2.5.1.1

In the Type column of the (0) Input line, set the Serial connection type (Fig. 2.5.1.2)

Figure 2.5.1.2

Click on the Opt button and in the tab that appears set the COM parameters of the PC port to which the Base station is connected, in the example it is connected to COM1 (Fig. 2.5 .1.3), Confirm the settings by clicking the OK button.

Figure 2.5.1.3

In the strsvr program, press the Start button (Fig. 2.5.1.4)

Figure 2.5.1.4

If the connection is correct, the square window in front of (0) Input will be green flashing, if there is no connection, it will be red. In the Bytes and Bps columns, information about the current amount of information received from the Database will appear (Fig. 2.5.1.5).

Figure 2.5.1.5

Click on the button Stream Monitor and in the window that opens Input Stream Monitor from the list of Streams select RTCM 3 (Fig. 2.5.1.6).

Figure 2.5.1.6

As a result, a window will appear with information transmitted from the RTCM Message Database, in which the messages highlighted in yellow on the screenshot should participate (Fig. 2.5.1.7). Quantity and numbers of RTCM message designations depends on the setting of the Base Station and may be different. Close the Input Stream Monitor window by clicking the Close button and stop the strsvr program by clicking the Stop button.

Figure 2.5.1.7

Configuring NTRIP Caster (a cloud source of messages for the rover)
In the Type column of (1) Output, set the type from connection NTRIP Caster (Fig. 2.5.1.8).

Figure 2.5.1.8

In the line (1) Output , press the Opt button and in the drop-down window, specify the COM port number for the Internet (in the example 2101), in the field Mountpoint< /strong> enter the name of the Base Station point under which it will be visible on the Internet (in the example of Smila), in the User ID and Password fields, if desired, enter the login and password under which clients will connect to the Base Station (Fig. . 2.5.1.9).

Figure 2.5.1.9

In the same tab, click the Mountp Options button and in the new in the tab that opens, fill in the fields according to the example (Fig. 2.5.1.10). In the Source ID field, enter the IP address that corresponds to this PC, in the Network field, enter the name of the settlement where the Base Station is located, in the fields < strong>Latitude and Longitude enter the coordinates of the Base Station.

Indicate the country, enter in abbreviated or full form RTCM messages issued.

Close the tab by clicking the OK button, close the NTRIP Caster Options tab by clicking the OK button.

Figure 2.5.1.10

Checking operation in the strsvr program
Start the strsvr program by clicking on the Start/Stop button (Fig. 2.5.1.11).

Figure 2.5.1.11

 

Since there are currently no clients connected to the Base Station via the Internet, the indicator in the line (1) Output lights up in yellow.

When connecting to the Base station via the client's Internet network, the information will look like in Figure 2.5.1.12

Figure 2.5.1.12

IMPORTANT - after completing the setup of the base station, it is important not to move it from its place. If the base station has been moved, it is necessary to perform its settings again.

 

Part two