Doppler Speed Log Its basic operation & function

Doppler log - An acoustic speed log based on the Doppler effect in which the wave lengths of moving objects appear to shift in relation to the observer. This shift can be converted to speed, thereby giving a very accurate result.
Generally, Doppler log can receive echoes from seabed only up to depths of 200 meters or so. However, beyond these depths, a weaker echo is available from a layer between 10 to 30 metres below the keel. The speed of the vessel can be determined as earlier but in this case, it will be with respect to this layer and not with respect to ground. This is called “speed over water” similar to that obtained from other types of logs mentioned earlier. In this case, the effect of current has to be allowed for to get the speed made good but the reflections from a layer deep down eliminate the effect of disturbances caused by the vessel itself and the effect of surface currents caused by wind and wave motion.
When the signal of echo sounder is bounced off the seabed, the speed indicated will be in relation to the fixed seabed and will, therefore, be speed over the ground.
PKO( Practical Knowledge Onboard)
Insta link. ➡️ anant_chandrakar
Facebook ➡️Anant chandrakar
Twitter ➡️@Anantchandraka5
Insta link. ➡️ Infinity_mariner
TELEGRAM ➡️ @Infinity_Mariner

[@rahulchauhan1408]

Good job 👍 in this video

[@sureshmalai4603]

Thanks lot it's very helpful sir

[@bhavyagoud2001]

Sir can you make video on steering console

[@BilalAhmed-sl3cc]

Hello sir I like your video. I'm waiting for more videos of yours to see and learn to pass my MMD exam. Sir I have a request to you is that can I download your video for education purpose as you know we have limited access to the internet at sea. If you permit me I'm thankful to you if no still much respect ✌

[@thanhvan798]

hi sir , i have a quesion ? why did we drop anchor , speed log fail , VDR alarm SPL fail ?

[@SantoshKumar-qz2bm]

Sir , I have doubt what is second display showing, just beside water type,and showing 0.0 kts what is 0.0 is it speed of water and ground or anything else

[@INFINITYMARINER]

It is the speed of the ship ,as the ship is at anchor it is showing 0.0 and the arrows besides speed indicates that ship is moving either to port or starboard