## Re: hey , i need help with "Rate of Turn"

Expand Messages
• Look at: http://www.navcen.uscg.gov/?pageName=AISMessagesA It says that: ROTAIS = 4.733 SQRT(ROTsensor) That would mean that ROTsensor = (ROTAIS/4.733) ^ 2 If
Message 1 of 3 , Oct 17 10:02 AM
Look at: http://www.navcen.uscg.gov/?pageName=AISMessagesA

It says that:

ROTAIS = 4.733 SQRT(ROTsensor)

That would mean that ROTsensor = (ROTAIS/4.733) ^ 2

If you plug 126 in the formula you get 708.7 (degrees / minutes) so the formula looks right... Yo need to take care of the negative values and exceptions (127 and 128) before applying the formula.

Bernard

--- In aismon@yahoogroups.com, "said" <elgourbi@...> wrote:
>
> Hey everyone
> im making a small program to decode ais sentence
> i successfully decoded ( MMSI , Repeat indicator ...)
> but i can't decode Rate of turn
> its from bit (42 to 49) and its signed
> i don't get the right value of rate of turn
> plzz help
>
• While not fun reading, you really really should take a look at the definition... get a copy of ITU 1371-4. It s free.
Message 2 of 3 , Oct 17 10:44 AM
While not "fun" reading, you really really should take a look at the definition...  get a copy of ITU 1371-4.  It's free.

`http://www.itu.int/rec/R-REC-M.1371/en`
Table 45.  3.1 Messages 1, 2, 3: Position reports

Or take a look at the code in libais:

-kurt

On Oct 17, 2011, at 1:02 PM, bdebbasch wrote:

Look at: http://www.navcen.uscg.gov/?pageName=AISMessagesA

It says that:

ROTAIS = 4.733 SQRT(ROTsensor)

That would mean that ROTsensor = (ROTAIS/4.733) ^ 2

If you plug 126 in the formula you get 708.7 (degrees / minutes) so the formula looks right... Yo need to take care of the negative values and exceptions (127 and 128) before applying the formula.

Bernard

--- In aismon@yahoogroups.com, "said" <elgourbi@...> wrote:
>
> Hey everyone
> im making a small program to decode ais sentence
> i successfully decoded ( MMSI , Repeat indicator ...)
> but i can't decode Rate of turn
> its from bit (42 to 49) and its signed
> i don't get the right value of rate of turn
> plzz help
>

• Ty so much :) it works :)
Message 3 of 3 , Oct 17 12:52 PM
Ty so much :)
it works :)
Your message has been successfully submitted and would be delivered to recipients shortly.