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3D ImageVector Mono User guide

This manual provides instructions for using the REDcatch 3D ImageVector Mono. We place high value in this documentation, but it is impractical to discuss all the possible applications of the ImageVector. Therefore, this manual and related tutorials do not replace professional training, but should help to prepare for training sessions and act as a reference thereafter.

Please contact your local distributor or us directly, if you have need for a training session and workflow integration at your place of work.

Do not hesitate to contact our support team directly if any questions arise on the topics described in these documents.

REDcatch GmbH

Tschaffinis 14

6166 Fulpmes

Austria

office [at] REDcatch.at

www.REDcatch.at

+43 5225 20203

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When using material from this document, please respect CC - BY - SA 4.0 https://creativecommons.org/licenses/by-sa/4.0/ and mention our company REDcatch GmbH, Austria and re-link our webpage.

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Contents Short instructions .................................................................................................................................... 4

Introduction ............................................................................................................................................. 5

Workflow overview ................................................................................................................................. 6

Setup, capturing Images and storing logfiles .......................................................................................... 8

Mount the 3D ImageVector on the camera ........................................................................................ 8

Connect cable to logger ....................................................................................................................... 9

GNSS initialisation and satellite signal .............................................................................................. 10

Wait and think ................................................................................................................................... 10

Important reminders ......................................................................................................................... 11

The first image ................................................................................................................................... 11

Take the photos ................................................................................................................................. 12

After survey ....................................................................................................................................... 12

Save data ........................................................................................................................................... 12

Advanced maintenance ......................................................................................................................... 13

Firmware updates ............................................................................................................................. 13

IMU calibration tool .......................................................................................................................... 13

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Short instructions

1. Mount the ImageVector on the camera and gently tighten 2. Connect the camera add-on to the logger. The socket clicks into place. 3. On/Off/Trigger LED illuminates constantly (if flickering, contact support) 4. Wait until the satellites LED starts to blink periodically. E.g. 9 flashes per cycle indicates

reception from 9 satellites. 5. From now on, try to keep the antenna vertical and do not tilt the camera past 40°. You must

also keep the camera upright in between taking photographs. 6. Allow the GNSS system to warm up for 5 minutes. 7. Take an easily identifiable photo (e.g. of your hand). Check that both the On/Off/Trigger LED

on the logger and the LED on the camera add-on blink as you take the photo (IMPORTANT). 8. Take photos. Wait at least 1 second between photos. 9. After the last photo, wait a further 2 minutes before disconnecting the camera add-on from

the logger (pull on the metal sleeve). 10. Save data (*.000, *.ubx) to your PC and remove unnecessary files from the logger.

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Introduction

The 3D ImageVector Mono allows for the acquisition of image centre positions and camera orientation in terrestrial photogrammetry. This provides “direct georeferencing”, transforming your camera into a precise and practical tool for surveying. It is suitable for use in terrestrial photogrammetry or handheld use from vehicles. Regardless, there is no need for ground control points. The 3D ImageVector Mono is used across multiple industries, including surveying, infrastructure, architecture, archaeology, geology and mining.

Function The 3D ImageVector Mono records the GNSS RINEX data (or corrected GNSS position data) and determines solid angles via an IMU. Trigger information with a resolution of 30 ns (nanoseconds) is recorded for each image. The 3D ImageVector achieves a position accuracy of 8cm (PPK, depending on the reception) and an angular accuracy of 1 °.

Logger The logger records data and also provides power to the ImageVector camera add-on. The batteries are self-contained and last approximately 4h during normal operation. LED's mounted on top of the logger indicate the quality of reception. Data from the logger is loaded to computer via USB cable.

Delivery The following products are included in the purchase of the 3D ImageVector Mono:

• camera add-on • data logger • charger • USB data cable • geotagging and PPK software: REDtoolbox • protective carry case

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Workflow overview

There are five main tasks involved in completing a photogrammetry project with the 3D ImageVector. These are shown in the image below. Fieldwork with the 3D ImageVector covers the first 3 tasks in this workflow. This manual provides guidelines for these tasks. Instructions and tutorials for completing the final tasks are available on the REDcatch website. Alternatively, for maximum simplicity, REDcatch offers a photogrammetric processing cloud service. Simply upload your files to the cloud, and we'll take care of the rest.

Preparation 1. Charge ImageVector and Camera. 2. Delete old files from logger. 3. Prepare SD memory cards. 4. Make a plan for photographing the object. 5. Ensure that expected environmental conditions are suitable (sunny, rain, cloudy, fog, snow

on the ground etc.).

Recording in the field 6. If you are using a personal base station, place this in a suitable location and power on before

setting up the ImageVector. 7. Set up the ImageVector in a location with good GNSS reception. 8. Mount the ImageVector on the camera's hot shoe and lightly tighten the lock. 9. Connect the camera add-on to the logger (the plug clicks into the socket). 11. The On/Off/Trigger LED should illuminate constantly (if it is flickering, contact support) 10. After a short time, the "satellite" LED on the logger will begin to blink. The number of blinks

in each cycle indicates the number of satellites from which it is receiving signal. 11. Before starting, take an easily identifiable test photo (e.g. of your hand), and check that the

trigger LEDs blink. 12. Wait for 3-12 minutes to initialise the GNSS. From now on, do not tilt the ImageVector past

45 degrees or move it abruptly. 13. Record your images. 14. After recording, leave the ImageVector switched on for approximately 2 minutes. After this

time, you may disconnect the camera add-on from the logger. Release by pulling on the metal sleeve, not the cable.

15. If using a personal base station, wait a further 2 minutes before switching it off. 16. Save data on your PC using the provided USB cable.

Postprocessing 1. Download/save base station RINEX data. This should cover a time span of at least 5 minutes

longer than the ImageVector. 2. Perform postprocessing and geotagging with the REDtoolbox software (if you do not have

the software, please contact REDcatch GmbH). 3. Check the validity of the output.

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Photogrammetric processing • Import images and image reference files that were created using the REDtoolbox, or • Open the project file created by the REDtoolbox (e.g. Agisoft Photoscan.psx)

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Setup, capturing Images and storing logfiles

Mount the 3D ImageVector on the camera • First, place the Camera add-on on the hot shoe of your camera. The LED on the ImageVector

should face toward you.

• Tighten the screw gently to fix the ImageVector on the camera.

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Connect cable to logger

• Connect the cable of the ImageVector add-on to the logger. Rotate the push-pull connector until it locks automatically.

• All LEDs blink for a short moment, after which the “On/Off Trigger” LED should remain on

permanently. If this is not the case (e.g. if it is flickering), please contact support.

• As soon as the “On/Trigger” LED lights up, the GNSS initialisation process begins.

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GNSS initialisation and satellite signal • If you are still in your office, please go outside. • Look for a place where there are no obstacles that could negatively influence the GNSS

reception. That is, somewhere that has a large view of the sky. • Leave the camera in this location for the initialisation period, but ensure that it is at least 1m

above the ground. Your car roof, tables, benches and tripods are examples of suitable places to leave it.

Be particularly aware of trees and buildings that may interfere with reception.

• Wait until the LED labelled “Satellites” starts to blink periodically (this can take up to 3 minutes). The number of times that the LED blinks consecutively in each cycle indicates the number of satellites available for positioning. You should have at least 8 satellites available before you proceed to the next steps.

Wait and think Before taking the first photo, you should wait a minimum of 3 minutes to receive the current GNSS almanac and allow for better postprocessing results. In many cases you should wait longer, up to 12 minutes if you have significantly changed location since last using the ImageVector or if you have not used the equipment for an extended period (e.g. 1 week). If in doubt, always allow the full 12 minutes.

Use this time to plan a good image capturing strategy for your object! Refer to our photogrammetry guidelines (separate document) for ideas on how to go about this.

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Important reminders • After turning on the 3D ImageVector, do not move the camera abruptly. Use smooth

movements. • Do not rotate the camera (tilt and roll) more than 40° from horizontal. The GNSS signal

will be lost and you will have to wait another 3 minutes for it to re-initialise. • Keep the camera at an approximately constant height, eg. in front of your face. Do not

lower the camera between taking photos, even while walking.

Take photos in the usual manner ✔

Hold the camera upright in between taking photos ✔

Do NOT lower the camera while walking ✘

The first image It is suggested that you begin recording by taking a photo of your hand, as this will serve as a reminder that it is the first image corresponding to the log file.

• IMPORTANT: Check the trigger LEDs while taking the first image! The "On / Trigger" LED on the logger should blink off briefly each time you take a picture. The LED on the camera add-on should blink as well. These LEDs must blink every time you take a photo. If not, your data is not being recorded! If the device is mounted correctly but the LEDs are still not blinking, please contact the REDcatch support team (support@redcatch.at).

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Take the photos Begin taking the images for your survey. You should not take more than one photo per second and should only use single-shot mode.

After survey • After taking photos, wait for at least 3 minutes before unplugging the ImageVector, as this

will allow you to get better results from postprocessing. As before, keep the camera upright and at least 1m above the ground during this time.

• Unplug the camera add-on from the logger by pulling the aluminium sleeve backwards. DO NOT pull the cable!

• Unscrew the camera add-on and remove it from the hot shoe. • Place everything back inside the carry case.

Save data • Use the USB cable to connect the logger to your PC/laptop. At least one LED should blink. If

not, please check the connection or try another USB port. If there are still no LEDs blinking, give extra power to the logger by plugging in the camera add-on cable (in the same way as during surveys).

• A mass-storage device is detected by your operating system. It can take 10 seconds or more

until the new drive letter is shown in Windows Explorer, please be patient. • Save the correct log file on your hard disk, noting that:

o The log files are named according to the format “year month day”.000 and *.000.ubx. Eg. 20171209.000 is a file from 9th of December 2017,

o The *.000 file contains a standard GNSS solution accuracy (2.5m), and o *.000.ubx is the RINEX file for postprocessing.

• When you save files to your PC, remove them from the logger. This will avoid confusion on future projects.

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• Unplug the logger from your PC and recharge it using the delivered charger. • Save images from your camera on your hard disk.

• Perform postprocessing and geotagging using the REDtoolbox software.

Advanced maintenance Firmware updates You should only update the firmware after consultation with the REDcatch support team. If you need to update the firmware or re-calibrate your 3D ImageVector, you can do so through the following procedure. Read through these instructions completely before attempting the process. If you are unsure whether you need to update the firmware, or if anything in these instructions is unclear, contact REDcatch BEFORE attempting to do it yourself.

Update firmware

1. Contact REDcatch support to receive a download link for new firmware (support@redcatch.at).

2. Connect your logger to your PC with the USB cable, in the same way as for copying data. 3. Copy the new firmware file named firmware.dat onto the logger. 4. Disconnect the logger, then reconnect. The LEDs should flash. This indicates that the

firmware has been installed.

IMU calibration tool IMU calibration should be avoided unless necessary. Examples of situations where you should re-calibrate include the following:

• Cameras with metal housing influencing the magnetometer / compass. • Misalignment of Northing due to influences of local magnet field

Calibration Tool

1. Contact REDcatch support to receive the download link for the configuration tool (support@redcatch.at).

2. Disconnect the logger, then reconnect.

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3. Plug the ImageVector camera add-on into the logger. In the case of the UAV version, plug the IMU chip into the logger.

4. Open the calibration tool named GNSSLoggerConfig.exe. 5. If the fields are blank, click Scan Devices. 6. Check that the Firmware Version field is showing the latest version (2.62).

Perform IMU calibration

1. Calibration is achieved by performing a series of movements with the ImageVector camera add-on directly (pictured below).

2. In the calibration tool section named “IMU Logging [ICL/IDA]”, click RESET, then confirm that

you want to reset the calibration. Note that all components of calibration are now shown as zero (in the field indicated in red in the image above).

3. Calibrate the gyroscope by simply holding the camera add-on still. This is most easily done by holding it flat on a table. Hold it still until the first calibration component shows a value of 3 (shown in the image above).

4. Calibrate the accelerometer by doing a full rotation of the camera add-on in 45 degree increments, pausing for a few seconds between each increment. The rotation can be around any axis. The second calibration component should now show a value of 3. If it does not, try the process again, rotating around a different axis.

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5. Calibrate the magnetometer by holding the camera add-on in your hand, then tracing

continuous “figure-eights” in the air by moving your wrist and forearm. Continue this motion until the third component of the calibration becomes 3.

6. The fourth calibration component (system) should change to a value of 3 soon after a value of 3 is shown for the other components.

7. TEST YOUR CALIBRATION by rotating the camera add-on around different axes and checking that the values for yaw, pitch and roll make sense. Testing the yaw requires that you know which way is north in your calibration environment. It is best to check with another compass, remembering to keep it away from the camera add-on to avoid interference with the magnetometer.

8. Once you are satisfied that the calibration was successful, click STORE. 9. Once you receive confirmation that the calibration was successfully stored, close the

calibration tool, disconnect the logger from your PC, and disconnect the camera add-on/IMU chip from the logger.