18. Januar 2020 aerialsurveybase Ollie

connecting a PhaseOne camera to CCNS4 for use with LiDAR

Last days, I got several requests regarding connecting a medium-format aerial sensor to a LiDAR, e.g. popular PhaseOne’s, such as iXM-RS150F, iXM-100 or IXUS to LMS-780 or ALS60.
Of course, there is always the demand for pin-point photography and register the exposures as events in the IMU data stream for further use, such as aerotriangulation and orthophoto production in combination with point clouds.

Technically, the good old CCNS provide the best solution, both for trigger and register, when using Camera Connector 1 and 2. Look at the pining:


CCN4 Backplane

Pin E Signal GND
Pin F Drift positive (analog, 5 Volts)
Pin G Drift negative (analog, 5 Volts)
Pin H 12 V positive
Pin K v/h value (analog, +/- 5 Volts
Pin L Exposure release, trigger
Pin M Midpulse, TTL
Pin  N OFL (on flight line ) signal
Pin P serial exposure
Pin S signal GND

Remember, for mid pulse use always double shielded, high quality RG58/RG59 cable. BNC connector can be soldered, but crimped ones are better, because a time critical TTL level digital signal will go through the wire.

Depending on the sensor, Mid Pulse should be configured as active low or high. Mid-pulse, MEP or Midpoint of Exposure Pulse is originally produced by the shutter and decribes the mid point of the shutter open time, e.g. it will define the exact center time-pulse in the middle of an instance of an exposure, e.g. 1/1.000 second)

In most CCNS, the pulse slope can be configured at SYSTEM CONFIG page #3:

Mid-pulse slope defines the kind of signal given by the CCNS to any external GPS receiver or AEROcontrol IMU:
ACT LOW: will lower the voltage on the external event to 0 volts upon receiving the external event signal from the sensor.
ACT HIGH: will raise (heighten) the voltage on the external event from 0 volts upon receiving the external event signal from the sensor.

Usually the slope can be defined in camera control box or. The procedure is similar to the definition of the 1PPS pulse trigger level in a RIEGL LIDAR machine. Additionally the OFL signal, originally to wake-up gyrostabilized suspensions mounts at start/end of Flight Line (e.g. GSM 3000/4000) can be used to start data recording on the RIEGL machine.

Check afterwards carefully, that events counting up, e.g. in SYS CONFIG #1 or AEC INFO page#2

The CCNS4 plugs are supplied by Souriau, France are of crimp type and include a straight cable clamp.

Note, that there are a lot of other vendors with suitable plugs, such as Canon or Aphenol. Important is the shell-size, the number of pins and the P (for Pins and normal orientation). CCNS5 plugs are standard LEMO crimp types.

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