User Manual Edition: 002 Date: 15-Sep-15 Status: Released Issue
DOCUMENT CHARACTERISTICS General User Manual Edition: 002 Edition Date: 15-September-2015 Status: Released Issue Keywords: Towertrack, Optical, Verification, Camera, Replay, Record, Accuraccy, Point of Origin Abstract: This document describes the towertrack optical verification system and its control software Contact Information Author: Stefan Lemmens Editor: Elke Vanuytven Contact Person: Niels Van Hoef Tel: +32 14 23 18 11 E-mail Address: support@intersoft-electronics.com Document Control Information Document Name: IE-UM-00833-002 Towertrack2 Optical Verification System - User Manual.odt Path: C:\Documents and Settings\elke\Desktop\RTG Manuals\ Host System: Windows 7 Software: OpenOffice.org 3.4.1 Size: 821021Bytes 2/33
DOCUMENT CHANGE RECORD Revision Date Reasons for change Pages Affected Approved by 001 14/08/15 First Edition, based on software V1.0.2.0 All SL 002 31/08/15 Changes after revision All EV 3/33
TABLE OF CONTENTS 1. INTRODUCTION...8 2. SET-UP & INSTALLATION...9 2.1. Hardware Description...9 2.1.1. Block Diagram...9 2.1.2. Led overview...11 2.2. Installation...12 3. SOFTWARE...13 3.1. Start-up & Main...13 3.1.1. Using the display area...15 3.2. Camera Interface...16 3.2.1. Camera Control...17 3.2.2. Camera Settings...18 3.2.3. Advanced Camera Parameters...20 3.3. Setup...21 3.4. Lens Calibration...24 3.4.1. General...24 3.4.2. Graph...26 3.4.3. Error...26 3.5. Results...27 3.5.1. Result...27 3.5.2. Graph...28 3.5.3. Timing...29 3.6. Compare...30 3.7. Replay...31 3.7.1. Replay Control...31 3.7.2. Replay Settings...32 4. OPERATING PROCEDURE...33 4/33
TABLE OF FIGURES Figure 1: Block diagram...9 Figure 2: Left-sided Towertrack...11 Figure 3: Right-sided Towertrack...11 Figure 4: Tripod Setup...12 Figure 5: Main Window...13 Figure 6: About Window...14 Figure 7: GT2000 Interface...16 Figure 8: GT2000 Advanced Parameters...20 Figure 9: Setup...21 Figure 11: Lens Calibration...24 Figure 12: Lens Calibration Graph...26 Figure 13: Lens Calibration Error...26 Figure 14: Results...27 Figure 15: Result Graph...28 Figure 16: Result Timing...29 Figure 17: Compare...30 Figure 18: Replay...31 5/33
TABLE OF TABLES Table 1: Led Overview...11 Table 2: Image Display Tools...15 6/33
CONVENTIONS USED G Note: This icon to the left of bold italicized text denotes a note, which alerts you to important information. % Caution: This icon to the left of bold italicized text denotes a caution, which alerts you to the possibility of data loss or a system crash. M Warning: This icon to the left of bold italicized text denotes a warning, which alerts you to the possibility of damage to you or your equipment. GLOSSARY OF TERMS AVI FOV GPS IE INI IP KML LAN LED PoE POI POO PPS ROI TOVS UTM Audio Video Interleave Field of View Global Positioning System Intersoft Electronics Initialization File Internet Protocol Keyhole Markup Language Local Area Network Light-emitting diode Power over ethernet Point of Impact Point of Origin Pulse per Second Region of Interest Towertrack Optical Verification System Universal Transverse Mercator coordinate system 7/33
1. INTRODUCTION The optical verification system is an addition to the RTG and Towertrack system in order to independently verify the accuracy of the simulated scenario's. Using high-power leds a camera can monitor the movement of the horn antenna with respect to reference points. The leds also provide range and timing information. The accuracy of the simulated scenario can be proven independent from the radar, and even without needing a radar to prove it. 8/33
2. SET-UP & INSTALLATION 2.1. Hardware Description 2.1.1. Block Diagram Figure 1: Block diagram. 9/33
The optical verification system consists of the following elements : Camera and lens mounted in an enclosure on top of a tripod. The enclosure contains a heater and a fan to control the temperature inside. PoE-adapter to supply power to the camera PC with the Towertrack Optical Verification System software installed. The PC also has a gigabitethernet card with 2 network-sockets. 8 leds are mounted on the towertrack and controlled by the LED Control Box To work properly the following connections are needed : Make sure all leds are connected to the correct outputs of the LED control box ; except for led8, this is controlled by the motor. Make sure the power-cord is connected to the camera and plugged in the 230V. Otherwise the fan and heater in the camera enclosure won't work. Connect a gigabit-ethernet port from the PC to the DATA IN -connector of the PoE-adapter with a network-cable. Connect the network-plug of the camera to the P+DATA OUT -connector of the PoE-adapter with the included network-cable Make sure the PoE-adapter is powered ON. This is indicated by the green led on the adapter. 10/33
2.1.2. Led overview There are 2 possible versions of the Towertrack2 setup, a left-sided and a right-sided. Figure 2: Left-sided Towertrack Figure 3: Right-sided Towertrack Table 1: Led Overview Index Name Description Status 1 Top Mast This is a reference led at the top of the mast. The UTM coordinates of ON this position are used to calculate the unknown positions of the other leds 2 Bottom Mast This is a reference led at the bottom of the mast. The UTM coordinates of ON this position are used to calculate the unknown positions of the other leds 3 Top Track This is an indicative led at the top of the track. This is used to locate the track in the image and to monitor the windload. ON 4 Bottom Track This is an indicative led at the bottom of the track. This is used to locate the track in the image and to monitor the windload. ON 5 Horn The position of this led is measured when a scenario is simulated. ON 6 Range This led switches ON every time the target is at an integer multiple of ON/OFF 100m from the radar. It then stays ON for 50ms. This is used to calculate the range between the target and the radar at every point in time. 7 PPS This led is controlled by a GPS and switches ON every second. It stays on for 100ms. This is the timing reference during the scenario. 8 ON/OFF This led indicates when the scenario is active, thus when the RF-signal is ON/OFF being send. ON/OFF 11/33
2.2. Installation Setup the tripod on a known position. It is very important to know the exact UTM coordinates of the camera. Make sure the camera is mounted on the gear-head as shown in the picture below, the front of the camera needs to be at the same side as the X -knob and pointing towards the towertrack. The Y -knob will then be at the backside and the Tilt -knob at the right side of the camera. Figure 4: Tripod Setup. 12/33
3. SOFTWARE 3.1. Start-up & Main To start the Towertrack Optical Verification System double-click on the icon on the desktop or select the program from the start-menu. This will launch the application. During the initialization the following splash screen is shown: After initialization the main window will be displayed: Figure 5: Main Window. This window consists out of the following parts: 1. Interface Selection : with this drop-down menu you can select which interface will be used to acquire the images. In replay mode the images will be read from file. 2. Control area : this area contains all controls to operate the selected interface. Depending on which interface is selected different buttons will be shown. 13/33
3. Display area : this area shows the latest acquired image. Depending on the status of the interface it might also show overlays or ROI's (regions of interest) to help the user. 4. View tab : here you can select which actions you want to perform or which data you want to see 5. Menu-bar : this menu contains the following items: File Close Application Ctrl+Q : select this item to close the application. This can also be done be clicking on the x in the upper-right corner of the main window or by pressing Ctrl+Q on the keyboard Help Show Context Help Ctrl+H : this will show or hide the context help box. This box gives additional information if you hover the mouse over an item. About... : opens the about window which also shows the current version number of the software. Figure 6: About Window. 14/33
3.1.1. Using the display area A tools palette is shown at the upper-left corner of the display area. This can be used to control the displayed image and contains the following items : Icon Tool Table 2: Image Display Tools Description Zoom Click the image to zoom in. Hold down the <Shift> key and click to zoom out. Selection Tool Select an ROI in the image and adjust the position of its control points and contours. Pan Pan around an image. Click an initial position, drag to the required position and release the mouse button to complete the pan. Point Select a pixel in the image. Line Draw a line in the image. Click the initial position and click again at the final position of the line. Rectangle Draw a rectangle or square in the image. Click one corner and drag to the opposite corner. If you right-click on the image display a short-cut menu will be shown. From this menu you can : Zoom to fit : makes the display zoom to fit the image. Clear ROI : removes the current ROI from the image. 15/33
3.2. Camera Interface Select the camera (GT2000) from the Interface Selection Menu. This will start the connection with the camera and show its controls and settings. Figure 7: GT2000 Interface. G Note: If the camera is not detected a warning Camera not found will be shown. Click Continue to return to the Replay -mode. Make sure all cables are connected properly and the PoE-injector is powered on. It might take 10-15 seconds to boot the camera. After this retry to select the GT2000 interface. 16/33
3.2.1. Camera Control For a GT2000 the control area contains the following elements: Snapshot : acquire one image with the camera. This is similar to taking a photo. Save Img : saves the current camera image to disk in an AVI-file. This file contains only 1 frame. Live : enables/disables live streaming of the camera images without processing them Record : enables the recording and processing. If auto-recording is disabled the user needs to unset this button before the acquired data is processed. If auto-recording is enabled, switching off this button will stop the recording and processing. Auto-Record : enable/disable auto-recording. In auto-recording mode the camera will only record and process images in which the ON/OFF LED (8) is ON. When the LED turns off the camera will process the acquired data and automatically start a new recording. Save AVI : select whether the recorded images need to be stored in an AVI-file. It also indicates the current status of the camera : Time : current recording time. This value is reset every time a new recording is started. Temperature : temperature from the camera from when the latest image was taken in C. Real Frame Rate : the real frame rate as measured by the camera in frames per second. 17/33
3.2.2. Camera Settings Perform the steps below to setup the camera on the interface tab in the view area. 1. Recording Path Make sure a valid path to a recording folder is entered here. 2. Orientation Select the orientation of the camera with respect to the towertrack. 3. Align Enable the alignment indicators and shows the alignment aid on the image display: 18/33
Align the camera : Move the horn to the center of the Towertrack. To do this use the Towertrack2 software to position the horn at 4m. Set the camera in Live -mode. Make sure the top track led (=led 3) is in the center of the alignment box by adjusting the X and Y knobs on the tripod until the X and Y indicators turn green. If the led is inside the red box on the display it will also be shown in the alignment graph. Since this is magnified the camera can be positioned more accurately. On the image display draw a rectangle around the bottom track led (=led 4) by selecting the rectangle tool and framing the desired led. Adjust the tilt knob on the tripod until the tilt indicator turns green. Make sure X and Y are still OK, if not re-adjust them. Stop the Live -mode by disabling the Live -button. Stop the Alignment by disabling the Align -button. 4. Region of Interest (ROI) The pixel coordinates of the ROI will be acquired by the camera in live mode or during recording. By clicking the Show -button the current ROI will be displayed on the camera image. With the rectangle tool this ROI can be modified. If the ROI is set as desired it can be committed with the Teach -button. To view the entire camera image the ROI can be reset to the full width and height of the sensor area with the Reset -button. For the GT2000 this will limit the frame rate to 49,78 frames per second. 5. Frames per second Displays the maximum theoretical frame rate value taking into account the acquired image size and the exposure time. This indicator will be green if the maximum value of 100 frames per second can be achieved. If it can not be achieved either the ROI or the exposure time need to be reduced. The exposure time can only be modified in Advanced -mode (see 3.2.3 Advanced Camera Parameters) 6. Apply & Save Click this button to apply the changes and save them in the ini-file. 7. Revert If you want to undo your changes, click this button to restore the settings from the ini-file. 19/33
3.2.3. Advanced Camera Parameters Some low-level camera parameters can be modified in Advanced -mode. To enter this mode go to the GT2000 Interface tab and press Ctrl+Shift+F12. Figure 8: GT2000 Advanced Parameters. PixelFormat : displays the pixelformat of the camera. The default value is Mono8. TriggerSource : displays how the camera is triggered. The default value is FixedRate. Camera ID : displays the ID of the active camera. Exposure : controls the exposure time of the camera in microseconds. The default value is 400 FrameRate : manually control the frame rate of the camera. Normally the maximum frame rate is calculated from the ROI and exposure time and applied but here you can set this to a specific value. The default is 100. To exit the Advanced -mode press Ctrl+Shift+F12 again or select another tab in the View-area. M Warning: Changing the advanced parameters might cause the camera to stop working properly or detecting any led. 20/33
3.3. Setup Once the camera is aligned we can start teaching the system where all leds are. Also the position of the radar and the camera itself need to be entered as well as some mechanical offsets and scenario parameters. This can all be done on the tab Setup Figure 9: Setup. When the tab Setup is selected the image display will show the overlays for all configured led positions as blue rectangles. This way you can have a quick overview to verify all positions at once. The tab itself contains the following items : Setup Display : shows a schematic drawing of the towertrack on which you can select a led to configure. Led parameters : these parameters define the selected led ID : a unique identifier Type : indicates the purpose of the led (Reference = led with known UTM coordinates, Track = led used for tracking, Timing = led used for timing purposes) Name : the name of the led describes its position in the setup Center : the center x and y pixel where the led was found during teaching Search Area : the region of interest where the selected led needs to be searched UTM Coordinates : for led's of the type "Reference" the UTM Coordinates need to be entered Timing : for led's of the type Timing pulse parameters (duration & interval) need to be entered Radar Position : UTM Coordinates of the radar position Camera Position : UTM Coordinates of the camera position 21/33
Offset Figure 10: Reflector and LED offset parameters Horn-LED Hor : the horizontal distance (X) between the horn and led in mm. Horn-LED Vert : the vertical distance (Y) between the horn and led in mm. Max Pixels : maximum difference between the average position of led3 and its largest displacement in pixels. If the displacement is more than this value than the software will indicate that there is too much windload. Scenario : parameters that describe the scenario simulated by the Towertrack. Range Start : defines the distance in meters between the radar and the simulated target at the moment the RF transmission is started and the ON/OFF-led (led8) turns on. Direction : defines whether the simulated target flies towards the radar (inbound) or away from the radar (outbound) To teach the application the positions and settings of all 8 leds perform the following steps for each led : 1. Select the desired led on the setup display. 2. Click the Show -button to show the led's current search area on the image display 3. Modify the ROI on the image display as desired by using the rectangle tool 4. Click the Teach -button to commit the updated search area 22/33
5. If a led is detected in the new search area the x and y pixel values of its center position will be displayed. If no led is detected the center position of the search area will be displayed as x and y. 6. Depending on the type of led : for reference-leds (led1, led2 and led51) enter the real-world coordinates in UTM for timing-leds enter the pulse duration and interval for track-leds no further parameters are necessary 7. Select the next led and repeat step 2 to 6. Click the Apply & Save -button to apply the changes and save them in the ini-file. If you want to undo your changes, click the Revert -button to restore the settings from the ini- file. 1 for led5 the bottom horn position needs to be entered, this is used to calculate the angle between the camera and the radar 23/33
3.4. Lens Calibration Since the lens is not flat but spherical this will cause aberrations or deformations in the image. To take this effect into account we have to calibrate the system. This is done by running a scenario with a linear movement. The software then knows that the non-linear part is caused by the optical system and will take this effect into account when calculating the positions of the leds. 3.4.1. General Figure 11: Lens Calibration. The General -tab of the lens calibration shows the following items : Linear Speed : linear speed of the horn antenna in mm/s used for lens calibration. Factor : the average resolution of the optical system in mm/pixel. This value is an average for the total region of interest but does not take into account the lens curvature. It is an indication of how well the calibration has been performed. Distance L1-L2 : the real-world distance between led1 and led2 in meters as measured with the theodolite. This value is derived from the UTM coordinates of both leds. Measured L1-L2 : the distance between led1 and led2 as measured by the camera in meters taking into account the latest lens calibration. Error L1-L2 : the difference between the real-world distance and the measured distance between led1 and led2. 24/33
To calibrate the optical system select the tab Lens Calibration in the View area and perform the following steps : 1. Select the Lens Calibration -scenario in the Towertrack2 software 2. Enter the linear speed of the horn for the selected scenario (default = 500mm/s) 3. Start Recording 4. Run the scenario from the Towertrack2 software 5. If the scenario is completed stop the recording 6. Click the Calibrate -button 7. Verify the distance measured between led1 and led2 8. Verify the error of the measured distance 9. Verify the Calibration curves (see 3.4.2 Graph and 3.4.3 Error) 10. Click the button to apply the calibration and save it in the ini-file. 11. Revert If you want to undo your changes, click this button to restore the settings from the ini-file. 25/33
3.4.2. Graph Figure 12: Lens Calibration Graph. This tab contains a graph that shows the real height in meters versus the measured pixels from the camera. The height is calculated using the elapsed time and the given constant linear speed. 3.4.3. Error Figure 13: Lens Calibration Error. This tab contains a graph that shows the difference between a linear fit and the real lens curvature in pixels. This indicates the error that would be made if the lens curvature was ignored. 26/33
3.5. Results When a recording is finished the results are automatically calculated and displayed on the Result -tab. 3.5.1. Result Figure 14: Results. This tab contains the following items : Last POO : UTM Coordinates of the last calculated point of origin. POO Range : distance between the point of origin and the radar. POO Azimuth : azimuth direction in degrees of the point of origin with respect to the radar. StDev Range : indicates the accuracy of the calculated point of origin in range. StDev Azimuth : indicates the accuracy of the calculated point of origin in azimuth direction. Windload : indicates how many pixels the towertrack has moved during the recording due to the wind. This is the difference between the mean position of the LED at the top of the track and its maximum displacement. Reference POO : UTM Coordinates of the reference POO. This is the theoretical point of origin from the scenario that the towertrack simulated. This is shown on the graph as a black X Mean POO : UTM Coordinates of the mean position of all calculated points of origin. This is shown on the graph as a green dot Load File : opens a file dialog to select a logfile from which data can be imported and displayed. Re-Process : recalculate the point of origin using the latest acquired data and the current settings. 27/33
To KML : export the latest result data to a KML file that can be opened in Google Earth History Graph : shows the position of all detected targets with respect to the reference point of origin. The latest POO is shown as a red dot, all previous points are shown as blue dots. Clear : clears all statistical data History Size : number of calculated points of origin since the last time the history was cleared. StDev X : standard deviation between all calculated points of origin in X direction with respect to the radar. StDev Y : standard deviation between all calculated points of origin in Y direction with respect to the radar. 50% Probability : 50% of all detected targets is assumed to be within this distance in meters from the mean point of origin. This is shown on the graph as a green circle. 3.5.2. Graph Figure 15: Result Graph. The graph on this tab can show all acquired and calculated data. Choose which 2 parameters to display in function of each other. 28/33
3.5.3. Timing Figure 16: Result Timing. The graph on this tab shows the status all LED's in function of time. In a normal situation only the timing leds (Range, PPS and ON/OFF) can turn off. All other leds should be always on. If this is not the case you should verify the search area(s) of the respective led(s). 29/33
3.6. Compare On the Compare -tab the measured data can be compared to the simulated scenario. Figure 17: Compare. A.ttref file can be exported from the Towertrack2 software and imported in the scenario path control Enter the UTM coordinates of the towertrack and click the Compare -button The differences between the reference scenario and the measured scenario in Range, Azimuth and Elevation will be shown in the corresponding graphs in function of time. Also the standard deviation, the 3σ value and the mean difference for these parameters will be calculated. You can also convert the theoretical scenario to KML by clicking the To KML -button so that it can also be displayed on Google Earth. If you open both KML files of the measured and the theoretical data in Google Earth you will get a 3D comparison of the data-sets. 30/33
3.7. Replay Previously recorded AVI-files can be replayed and reprocessed. To do this select Replay from the Interface Selection -menu in the main window. Figure 18: Replay. 3.7.1. Replay Control In Replay -mode the Interface -tab contains 3 buttons to replay the selected file. Play : start replay from the beginning of the selected file Pause : pause or continue replay of the selected file Stop : stop replay of the selected file 31/33
3.7.2. Replay Settings In Replay -mode the Interface -tab contains the following items : Replay File : select a valid AVI-file to replay Get Configuration From : select which set of parameters need to be used for analysis INI : selects the parameters as stored in the INI-file AVI : selects the parameters as stored in the AVI-file during acquisition. User : selects the parameters as shown on the user interface AVI Index : index of the current frame in the AVI-file. You can set this value to view a certain frame from the file. Frame Number : the sequence number of the frame during the acquisition. This may defer from the AVI index if not all frames were recorded for example during auto-recording. Timestamp : time of the selected frame during the acquisition. Exposure : the exposure time of the camera during the acquisition of the selected frame in microseconds. If a file is completely replayed (from start to end of file) a new result will automatically be calculated using the selected set of parameters. 32/33
4. OPERATING PROCEDURE The following steps describe how to perform a complete measurement : 1. Make sure the camera/tripod is set-up properly and all cables are connected as it should 2. Start the application 3. Select the interface GT2000 4. Enable Live -mode 5. Align the camera in X, Y and Tilt 6. Disable Live -mode 7. Teach ROI for acquisition 8. Apply & Save the current settings 9. Go to Setup 10. Teach the position of all leds. 11. Verify the positions of the camera and radar, the offsets and the scenario parameters 12. Apply & Save the current settings 13. Perform a lens calibration 1. Go to Lens Calibration 2. Select the Linear Scenario from the Towertrack2 Software 3. Start Recording 4. Run the scenario from the Towertrack2 Software 5. Stop Recording (after the scenario has finished) 6. Click Calibrate 7. Verify the calibration curves 8. Apply & Save the calibration parameters 14. Perform a measurement 1. Select the desired scenario from the Towertrack2 Software 2. Start Recording 3. Run the scenario from the Towertrack2 Software 4. Stop Recording 5. View the results 33/33