is it possible to determine vehicle speed when dash cam doesn't have GPS function?

[DieselFish]

is it possible to determine vehicle speed when dash cam doesn't have GPS function?

thanks!

 

[niko]

is it possible to determine vehicle speed when dash cam doesn't have GPS function?

thanks!

of course it's possible by using simple equation from school

Speed Calculated by Distance and Time

 

[Hillbilly]

Or looking at the speedo LOL

Divide time bay distance or vice versa Its 58 years since I was at school

 

[kamkar]

All Danish roads have markers at the roadside every 50 M, so its just a matter of calculating distance travled in ? time.

 

[roadbug]

Of course there is, as several have pointed out, time to travel a distance can be used.
Take the video you want to determine speed from and use some software so you can look at individual frames. Then pick 2 spots in each frame that the distance is known and see how long it takes to cover that distance. From there you could use the web site Niko listed to get your speed.
I also read forums for radar detectors and they have mentioned that there are some systems that use this method to determine a cars speed. They do not show up on a detector as there is nothing being emitted. One system can even measure the speed of all the cars on a multi lane highway.

 

[sludgeguts]

I've had a couple of instances where someone has commented on my vids that I was going too fast.
By looking at set points/objects and noting the time at each point. If you look on google earth, there is a ruler function which you can use to measure the distance between those points (lamp posts, street signs, buildings...).
It's not deadly accurate but you can get a reasonable approximation of your speed.

 

[Frankzzz]

If you look on google earth, there is a ruler function which you can use to measure the distance between those points (lamp posts, street signs, buildings...). It's not deadly accurate but you can get a reasonable approximation of your speed.

Try this:
http://www.daftlogic.com/projects-google-maps-distance-calculator.htm

 

[Quick]

The assumption is that your playback rate matches your record rate -- if you are recording at 30fps then you must playback at 30fps.

 

[Gabolinche]

Or you can just base your calculations on the time-stamp in the video (assuming it includes seconds) avoiding any influence from frame rates...

 

[q_hung]

is it possible to determine vehicle speed when dash cam doesn't have GPS function?

thanks!

Try using the Registrator Viewer: http://www.registratorviewer.com/index_en.html

My cam sometimes loose GPS signal and can not display the vehicle speed. When viewing the videos by the above software, it can calculate and display the speed (it is rather exactly in compare with the speed recorded by my cam when having GPS signal).