[Elphel-support] 答复: sync stereo with lidar

[Tao Zhang]

Hi Andrey,
We prefer to use GPS to synchronize stereo with lidar.
Where do those images that contain timestamp store in internal disk? Can we get it from ethernet continuously?

Tao Zhang
章   涛

发件人: Andrey Filippov [mailto:andrey at elphel.com]
发送时间: 2018年2月1日 1:52
收件人: Tao Zhang <tao.zhang at blacksesame.com.cn>
抄送: Elphel Support <support-list at support.elphel.com>; Elphel Sales | Olga Filippova <sales at elphel.com>; Winston Zhang <winston.zhang at blacksesame.com.cn>; Qun Gu <qun.gu at blacksesame.com>; Pioneer Li <pioneer.li at blacksesame.com.cn>
主题: Re: [Elphel-support] sync stereo with lidar

Hi Tao,

There are several ways how to do that:
One method would be be to get camera sync pulses for each frame and use external electronics to match with the LIDAR.
Another is to provide pulses from the LIDAR to the camera and record them with in-camera FPGA logger (https://wiki.elphel.com/wiki/Event_logger), together with the camera frames. In this case the camera will record 2 types of events:
 -  image frames with the frame number, frame timestamp that will be recorded in each frame header as Exif.
 - external pulse
Each of the two types of events will have a logger timestamp (with microsecond resolution). Logger can also record GPS timestamps (for serial GPS only and 103696 board -https://wiki.elphel.com/wiki/103696) and IMU (https://wiki.elphel.com/wiki/103695), in your case there are just 2 types listed above.

Both output (+5V pulses) and input (3.3V..5.0V) are available through the 2.5mm audio connector (marked "sync" https://wiki.elphel.com/images/0/0f/NC393-CS_marked_ports.jpeg ), here is the pinout and description: https://wiki.elphel.com/wiki/103891 .

Andrey

---- On Wed, 31 Jan 2018 04:19:04 -0800 Tao Zhang<tao.zhang at blacksesame.com.cn<mailto:tao.zhang at blacksesame.com.cn>> wrote ----
Hi Andrey,
We are going to use stereo with lidar. We need to sync stereo frames with lidar point cloud. Do you have any suggestions on how to do that?
Thanks.

Tao Zhang
章   涛

_______________________________________________
Support-list mailing list
Support-list at support.elphel.com<mailto:Support-list at support.elphel.com>
http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://support.elphel.com/pipermail/support-list_support.elphel.com/attachments/20180201/aa54beeb/attachment-0001.html>