Mobile Mapping. VZ-400 Conversion to a Mobile Platform Guide. By: Joshua I France. Riegl USA

Mobile Mapping VZ-400 Conversion to a Mobile Platform Guide By: Joshua I France Riegl USA

Table of Contents Introduction... 5 Installation Checklist... 5 Software Required... 5 Hardware Required... 5 Connections... 6 Communication Settings... 6 Hardware Connections... 10 Software Connections... 12 NMEA Messages... 12 Data Logging... 13 System Lever Arms... 14 Integration Settings... 18 RiAcquire Overview... 23 Acquiring Data... 26 Boresight Acquisition Checklist... 28 Summary... 29 References... 29

Figure 1: LV-POSView POS Internet Address window... 6 Figure 2: Network Sharing Center- Windows 7... 7 Figure 3: Local Area Connection Properties Window... 7 Figure 4: The active window is where the IP Address for the Laptop is to be changed... 8 Figure 5: GPS Connection Cable for the VZ-400... 10 Figure 6: VZ-400 interface connections... 11 Figure 7: GPS Sync. Cable to POS connections... 11 Figure 8: LV-POSView main window... 12 Figure 9: LV GPGGA message settings for Synchronization with the Scanner... 13 Figure 10: Logging output for Trajectory Processing... 13 Figure 11: IMU Reference to center label information... 14 Figure 12: VZ-400 Mobile mount configuration... 15 Figure 13: VZ-400 technical drawings... 15 Figure 14: Lever Arm and mounting information required for the system configuration... 16 Figure 15: System on a mobile surveying platform... 17 Figure 16: DMI mounting information window... 17 Figure 17: Opening window of Integration settings... 18 Figure 18: INS-GSP Settings... 19 Figure 19: INS-GPS Calibration table in the integration settings window... 19 Figure 20: Scanner Communication Settings... 20 Figure 21: Scanner Synchronization method selection... 21 Figure 22: Calibration Settings for the Scanner... 22 Figure 23: Scanner Project logging Settings... 23 Figure 24: Laser Configuration project settings.... 24

Figure 25: Configuration for the VZ-400... 25 Figure 26: License Manger inside of RiAcquire... 26 Figure 27: New Project screen in RiAcquire... 26 Figure 28: Scanner Settings Dialogue... 27

Introduction The VZ-400 is a fast and highly accurate tripod laser scanning solution. Its ability to synchronize with an external time source gives it a unique ability to also work in a mobile system. The mobile system configuration is described in detail for integration with an Applanix POS LV system. Most other navigation systems are able to be used with the VZ-400; please consult the RiAcquire Manual for specifications. Installation Checklist Software Required RiAcquire MLS RiProcesss SDCIMPORT RiWorld Trajectory Processing Software INS-GPS solution controller Hardware Required IMU GPS antennas and Receiver VZ-400 (or other Riegl scanner)* Data logging capabilities for IMU and GPS data Shock mount GPS-RS232 to BNC cable for PPS pulse and NMEA message Ethernet Cables (3) VZ-400 Ethernet cable with direct connection pigtail (only use cross over if directly communicating with laptop) Laptop Power cables Power source BNC antenna cables IMU cable Hub or switch for common data communication between instruments *Other requirements for Riegl LMS scanners that are not VZ-400 that exist; contact support@rieglusa.com ** The Applanix POS LV system is featured in this document. For a list of other INS-GPS solutions capable of use with Riegl LMS products, please consult the RiAcquire-MLS manual and support@rieglusa.com

Connections Using the correct cables to connect and communicate between the VZ-400 to an INS-GPS solution is the first step in the integration. Communication Settings Internet Protocol (IP) addresses of both the POS and the Scanner need to be in the same domain. A domain is the first six numbers of an IP address. The default IP address of a Riegl VZ-400 scanner is 192.168.0.128. The default of IP of some POS systems is 129.100.0.110. This IP address for the POS system can be easily changed using the LV (MV)-POSView program that comes with the Applanix POS system. The subnet mask must also be the same. The default setting for Riegl scanners is 255.255.255.0. Some POS system may have the Subnet mask of 255.255.0.0 as a default; this must be changed as well. Changing IP Address of the POS Connect to the POS Go to settings > Installation> POS IP Address Then, simply change the IP Address to the desired domain as shown in Figure 1, and click apply. Figure 1: LV-POSView POS Internet Address window *If not connected to the POS the change will not be implemented. Changing the Laptop Address In order to log into either the scanner or the POS with a different domain than the IP domain of the Laptop, one must change it to match the domain of the POS or the Scanner. Go to the control panel> Networking and Sharing Center (Figure 2). Click local area connection > Properties (Figure 3).

Select Internet Protocol Version 4 (TCP/IPV4) > Properties (Figure 4). Adjust IP address and Subnet mask to match the POS or VZ-400. Figure 2: Network Sharing Center- Windows 7 Figure 3: Local Area Connection Properties Window

Figure 4: The active window is where the IP Address for the Laptop is to be changed

Changing the VZ-400 s IP address Use the HMI to change the VZ-400 s IP address. Project Setup Menu 3.1 LAN & WLAN LAN & WLAN menu To configure the LAN & WLAN: At project setup menu, use Cursor Key up / down to highlight LAN & WLAN then press Enter Key. The image above shows the LAN & WLAN menu. From project setup menu, use Cursor Key up / down to highlight LAN & WLAN then press Enter Key. The image above is the page after project setup menu. To select from LAN0 (100 MBit), WLAN, and

LAN0 (1GB), use Cursor Key up / down to highlight page x/3, < > changes then use Cursor Key left / right to change communication type. To change configuration for each communication type, use Cursor Key up / down to highlight then press Enter Key. Then use Cursor Key left / right to change configuration type. When desired configuration is selected, press Enter Key to save and exit option. To change the IP address, IP subnet mask and IP gateway, follow steps previously described in this paragraph. Once all systems are on the same internet, domain integration can begin. Hardware Connections The VZ-400 comes with a GPS Interface Cable, Figure 5, with a BNC connector for the PPS pulse and a serial connector for the POS NMEA message. This is connected on the scanner via the trigger socket, see Figure 6. Figure 5: GPS Connection Cable for the VZ-400

Figure 6: VZ-400 interface connections The GPS connection cable is then connected to the POS COM port(s) and to the PPS OUT, BNC connector, Figure 7. Figure 7: GPS Sync. Cable to POS connections The TCP/IP cable from the scanner and the POS should be connected to a hub and then connected to a laptop or acquisition computer. This completes the hardware connections of the scanner to the POS. The POS should be connected to the IMU and to the GNSS antenna(s) before starting the system.

Software Connections LV-POSView NMEA Messages Two NMEA messages are recommended as the best to use for this system. The first for POSLV s is the GPGGA message and for POSMV s, the only message is GPZDA. The GPZDA will work for both LV and MV units. To make these message selections, connect to the POS using the POS controller software, Figure 8. Figure 8: LV-POSView main window Then, go to Settings > Input/Output Ports. Then, select the correct com port tab that corresponds to the com port the scanner GPS cable is connected to. In this case, it is com port 1. Select the desired message and the talk ID and an Update rate of 1 HZ. Also, select a Baud rate for the com port use 9600.

Figure 9: LV GPGGA message settings for Synchronization with the Scanner Data Logging Click Apply then close. Next, go to Logging > Ethernet logging. Select POSPac. Then, check box 3- Primary GPS Data, as shown in Figure 10: Logging output for Trajectory Processing, Figure 10. Figure 10: Logging output for Trajectory Processing Do the same for PC Card Logging to create a backup trajectory.

System Lever Arms The reference point for this system integration will be the top of the IMU at the center mark. Four main lever arm measurements are required for accurate trajectory data for LiDAR processing. The first is for the offset between the top label of the IMU and the actual IMU reference point. This should be listed in a manual or listed on the label, Figure 11. Figure 11: IMU Reference to center label information The next lever arm is to determine the distance from the center of the IMU to the primary GPS antenna. This measurement should be within 3 centimeters. The higher the accuracy, the better the GAMS solution will be and the quicker it will be calculated. The next lever arm to be measured is the distance to the VZ-400 reference point from the IMU Reference point, Figure 12 and Figure 13.

Figure 12: VZ-400 Mobile mount configuration Figure 13: VZ-400 technical drawings

Figure 14: Lever Arm and mounting information required for the system configuration Entering the Lever Arms Settings> Lever Arms & Mounting Angles There are 2 initial distance measurements that need to be made and then entered into their corresponding sections: one from the IMU reference to the primary GPS antenna and one from the IMU reference to the top of the IMU. Remember that the origin of the system is the IMU reference with X-axis forward. Due to the way this system mounts, a 180 rotation about the X axis needs to be entered in the IMU Frame with respect to the Reference Frame section. The Reference Frame is the vehicles with X being forward motion, Y being to the right or starboard side, and Z being down. DMI The final lever arm measurement is from the bottom of the driver s side rear tire to the reference point. This 3 dimensional measurement is best measured with 3D scan from 2 or more scan positions using the VZ-400. This will allow for a measurement of around 3 cm or better accuracy. The other measurement that is needed is the circumference of the wheel. This number is used for the DMI scale factor calculation, Equation 1.

Figure 15: System on a mobile surveying platform Equation 1: DMI Scale factor d Diameter of the wheel C Circumference of the wheel This information is entered on the sensor mounting tab of Lever Arms and Mounting Angles window, Figure 16. Figure 16: DMI mounting information window

RiAcquire Integration Settings Open RiAcquire and then go to System > Integration Settings. Figure 17: Opening window of Integration settings Then, add both a scanner and INS-GPS using the plus button and select the type and enter the proper serial number. IMPORTANT! An S must be added before the scanner Serial number! Next, select the connect type for the INS-GPS 1 of TCP/IPv4 and then enter the IP Address, Figure 18. Then, check the calibration tab to make sure the axes are north, east and down, Figure 19. The matrix IMU to Body is left as an identity matrix because the trajectory software will handle the rotation of the IMU to the Body frame.

Figure 18: INS-GSP Settings Figure 19: INS-GPS Calibration table in the integration settings window

Select Scanner 1 and enter the correct IP Address for the scanner. Then, go to the synchronization tab and select External GPS RS232 for the Used Synchronization Method. Set the time Tag Data String Format to GPGPPA, unless using a POS MV system; then use GPZDA. For all Applanix POS systems, it s Data First. POS LV is Positive PPS Trigger Edge and POS MV is Negative Trigger Edge. Finally, select the correct GPS RS232 settings that match the settings in LV-POSview, Figure 9. The settings selected should be similar to Figure 21. Figure 20: Scanner Communication Settings

Figure 21: Scanner Synchronization method selection All default settings in Scan Synchronization and Options tabs are left alone. The final settings need to be entered under the calibration tab, Figure 21. The rotational matrix is used to align the scanner s own coordinate system with the IMU s coordinate system. Both coordinate frames follow the right hand rule. Use Figure 13 for understanding of the Scanner s reference frame. The IMU has been rotated but we have corrected this rotation with LV-POSView, Figure 14. Therefore, the IMU s frame is in line with the vehicle s reference frame NED.

Figure 22: Calibration Settings for the Scanner This completes the integration settings needed in RiAcquire. Test the connects with the connection test. If the systems are properly connected, it will show 2 green check marks. Then, click ok and use the password ican, it is not case sensitive.

RiAcquire Overview Environment Settings Next, go to environment settings. Here all display, unit, and project defaults can be altered and set. The main settings to adjust will be presented. Under project select the scanner tab and switch the Logging Method from Single File to Multiple Files, Figure 22. Figure 23: Scanner Project logging Settings The next feature to prepare ahead of an acquisition mission is the Laser Configuration. Go to the Laser Configuration tab under the Project menu. Here, add as many possible look directions as needed to complete the boresight or mission, Figure 24. To add a new configuration, click the plus button then highlight the new configuration and click the pencil button. This opens the configuration window, Figure 25. The target distance and ground speed numbers are just for parameter calculation and do not have to be adjusted for every mission. Set Scan Mode to Line, set Measurement Program to High Speed Mode, and set Frame Start to the desired orientation.

Figure 24: Laser Configuration project settings.

Figure 25: Configuration for the VZ-400 License Manager Each Scanner has a unique license code for data acquisition that does not require a dongle. It must be entered into the license manager before scan data acquisition is allowed. Go to System > License Manger and then click import and select the *.lic file provided with the system documentation, Figure 26 or click in the white space and type the 32 character license code for RiAcquire.

Figure 26: License Manger inside of RiAcquire Acquiring Data Create a new project in RiAcquire, Figure 27. Then, click the green star button to initialize all instruments, scanner and INS-GPS. The scanner settings window will pop up. Select the laser configuration desired; also enter the atmospheric parameters, Figure 28. Click the globe with the green dot to start the 5 minute countdown for the INS-GPS static session. Once finished, start the scanner with the scanner icon and green dot; then start logging with a pencil, the scanner icon and green dot. Similar icons with red dots stop logging and stop the scanner. The scanner must be stopped in order to change configuration settings. Figure 27: New Project screen in RiAcquire

Figure 28: Scanner Settings Dialogue

Boresight Acquisition Checklist 1. Select a target rich environment with a good sky view 2. Make repeated passes over the same target area at difference angles a. Depending on orientation, at least 8 different angles. b. With 0 being forward the follow combination would work i. 30, 60, 90, 120, 150 ii. 330,300, 270, 240, 210 3. Integration setting between the POS and Scanner a. IP addresses and NMEA message 4. Lever arm measurements (Note must be connected to POS for changes to stick) a. Make top of IMU Ref point b. Rotate POS frame to match North, EAST, Down c. DMI Scale factor must be correct d. REF to GPS 1 e. REF to GPS 2 f. REF to DMI g. Times set to UTC time 5. GAMS measurement of antenna separation 6. Start base station data logging 7. GAMS calibration procedures 8. Static Session for 5 minutes 9. Initialization of RPY values 10. Collect scan data at all preset angle values 11. End with 5 minute static session

Summary Mobile scanning systems have a wide range of use and in conjunction with tripod scanning will provide excellent data for feature extraction. The VZ-400 mobile system is seen as a system to fill the gap between fully integrated mobile mapping systems such as the VMX-250 and tripod scanning on a mobile lift, i.e. TopoLift. While this manual describes in detail how to integrate a VZ-400, it can also be used for integration of any Riegl scanner with the proper sync timer functions and hardware. References 1. Rieger,P., Studnicka, N., and Pfennigbauer, M. Boresight Alignment Method for Mobile Laser Scanning Systems. RSPRS. Moscow, Russia. December 2008. <http://riegl.com/mediaevents/projects/mobile-scanning/project/p-rieger-n-studnicka-m-pfennigbauer-boresightalignment-method-for-mobile-laser-scanning-syste/>. 2. Applanix A Trimble Company. POS LV4 Installation and Operation Guide, June, 11 2008. 3. Applanix A Trimble Company. POS MV V4 User Guide, May, 31 2006. 4. Riegl Laser Measurement Systems GmbH. 3D Terrestrial Laser Scanner Riegl VZ-400/ Riegl VZ-1000. Horn, Austria. October 10, 2010. 5. Riegl Laser Measurement Systems GmbH. RiAcquire-MLS. Horn, Austria. March 2011.