Search and Rescue

[Andres_RG]

SAR search patterns is a Search & Rescue, SAR, utility that generates a GPX file for OpenCPN or Google Earth.
Chart Work - SAR search patterns | Official OpenCPN Homepage

Now the aim is that it be in accordance with IAMSAR specifications.
Life at sea is a serious thing

See the initial thread at: http://www.cruisersforum.com/forums/...ute-75425.html

[SaltyPaws]

Hi Andres,

I have been looking at Chart Work for a while now, very impressive! I would take up your offer on implementing Chart Work functions in OpenCPN, which you made one the site some 2 years ago.
I am currently working to implement the SAR functions in an OpenCPN plugin. The benefit of this plugin would be cross-platform availability, and having the functions direclty in openCPN.
Would you be able to share the formulas you are using? also, is is possible to have a look at the source code? My source code can be found here: https://github.com/SaltyPaws/route_pi.git.

I have created the GUI for search patterns, now I need to code the functions that create the routes.

[Andres_RG]

Originally Posted by SaltyPaws

Hi Andres,
I have created the GUI for search patterns, now I need to code the functions that create the routes.

Hi SaltyPaws,

at this moment I am updating the code to fit IAMSAR requirements. Is it very simple. For the moment, if you want to follow with the dll, take this into account.

/*
FILE: SARpatterns.h

This file contains proprietary information of Andrés Ruiz Gonzalez
Copying or reproduction without prior written approval is prohibited.
Andrés Ruiz. San Sebastian - Donostia. Gipuzkoa
Navigational Algorithms
Copyright (c) 2012
*/

void gpxExpandingSquareSearchPattern( double B0, double L0, double R0, double S, int n, char *gpxFileNameWithoutExt );
void gpxSectorSearchPattern( double B0, double L0, double R0, double legD, char *gpxFileNameWithoutExt );
void gpxParallelSearchPattern1ship( double B0, double L0, double R0, double legD1, double legD2, int nLegs, char *gpxFileNameWithoutExt );
void gpxParallelSearchPattern2ships( double B0, double L0, double R0, double legD1, double legD2, int nLegs, char *gpxFileNameWithoutExt );

Regards,

[Andres_RG]

Designation of the search patterns

First letter:

• S - Square
• V - Sector
• P - Parallel
• C - Creeping line
• T - Track-line

Second letter:

• S - Single unit
• M - Multy-unit

The program Chart Work - SAR search patterns | Official OpenCPN Homepage generates a GPX file for SS, VS and PS/PM (2 SRU).
PM has two routes, left and right that can be used for one unit (SRU: search and rescue unit).


The GPX file also has two waypoints: the Datum and the CSP.

• Datum: A geographic point, line, or area used as a reference in search planning.
• CSP: Commence search point. Point, normally specified by the SMC, where a SAR facility is to begin its search pattern.

The name of the GPX file is composed by date, time, type of pattern and orientation. For example 20120717083816 SS 270.gpx
Examples are attached.

[Andres_RG]

Dear Jean Paul,

Is it useful an spread sheet to calculate the new datum due to the effect of wind and current: leeway and drift?

I mean its true value, its usefulness in a SAR operation, because the effort is great.

IAMSAR.Anexo K.xls may be opened with excel and Open Office.
See Annexe K: http://www.directemar.cl/images/stor...iamsar%202.pdf
I do not have the english version.

Regards,

[NAV]

English version of IAMSAR can be found here:
Digital downloads

Edit: hmm... only the first 15 pages I noticed.

[latchodrom]

Hola Andres,
In France, it's the job of the RCC ( CROSS) to determine the datum for a search pattern.
The OSC just adjust a few datas ( tracking space, orientation, etc..) in accordance to the on scene conditions and the capabilities of his ship.
But if calculating a datum is not the primary job of the SRU, if we can have such a tool on board, it will be very usefull for many reasons.
We never know what can happen in SAR and to be able to determine the "total drift" of an object at sea is definitely a good thing.
Your SAR pattern software is already a great tool for us and I know that you can improve it at his maximum...
Thanks for all your great job !
Jean Paul

[SaltyPaws]

Hello Andres,

The GUI for the OpenCPN SAR plugin is ready - you can have a look at it here: https://github.com/SaltyPaws/SAR_pi.git. I just finished my other plugin, calculator pi, so I can now dedicate some time to SAR again.

Thank you for sharing the functions. I will not take the dll approach as one of the requirements of the SAR_pi plugin is that it needs to be cross platform. Would you be able to share the cpp and header file of the SAR functions? The native files would be the most compatible on different platforms. Keep up the good work

[rgleason]

Thank you Salty Paws and Andres RG! The SAR efforts are very impressive. Idea of calculating drift sounds good. Do you think that perhaps sometime later you might be able to incorporate some of Andres RG other "Chart Work" Functions, such as a Range and Bearing Object and features, etc?

Thanks again!

[latchodrom]

Hi all !
I'm really interested by this drift calculator...
But Really know nothing about compiling...
Is it possible to have a standalone plugin? or a pic to see what it's stand for?
What kind of objects did you include in the calculator... PIW/Liferaft/plane?...;-))
Wow!
If you can do such a tool gentlemen, you are the best !
I think I have to try to learn compiling...
Kind regards
Jean Paul

[Andres_RG]

Bonjour Jean Paul,

I could not find the IAMSAR text in English.
Where is it available?

(See the toll for manual calculation of the patterns.)

[latchodrom]

Hola Andres,
I surely have the vol 3...
Let me have a look for finding the vol 2 and i will send you both...
regards
Jean paul

[latchodrom]

Here's a link that might be of interest :
National Search and Rescue Manual
Regards
JP

[latchodrom]

A few pdf.files that might be of interest ...

[Andrew Troup]

Regarding the orientation of the square search pattern:

For a sailing vessel, it would be helpful if the datum direction corresponded with the hypotenuse or diagonal of the square, because if this is set to the true wind direction, the vessel can either just lay both the windward legs, or not quite lay them, but in equal measure.

This would only save having to add or subtract 45 deg, so not a biggie - but every little helps when you're under the gun, and it would be a shame to get it wrong and not find out until leg four.

It would also be a helpful reminder to a skipper who might not immediately realise they have to do this.

To those who say "why would you sail when you're searching" ... I can only say i hope you have a motor which is so quiet you would stake your crew's life on hearing them over it. Plus it is helpful to have sail up in order to be able to heave-to steadily, and ideally with some heel, when you come to recover them.