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Profile for jakob



Name jakob
Email Address jakob@sailport.se
AvatarUsers avatar
Posts364
Board Signature
...one of the guys behind the game...
  • Re: IMSYC 2011
    Board » General Discussion
    You people are fantastic! What enthusiasm and engagement!!! I will try to get some students to this thread. :-)
    ...one of the guys behind the game...
  • Re: IMSYC / SOLstice Cup
    Board » General Discussion
    You find them in Homework set 5 and 6.
    ...one of the guys behind the game...
  • Re: IMSYC / SOLstice Cup
    Board » General Discussion
    ...and if you want to play around with hull shapes etc to investigate effects on CP, trim, stability etc you might want to try the msy_hydrostatics-code that I put on the same web-page. The code lets you import hull shapes and then stretch them in various ways :-)
    ...one of the guys behind the game...
  • Re: IMSYC / SOLstice Cup
    Board » General Discussion
    Regarding IMSYC: If you are interested in the rule for the IMSYC race 2011 you can find it here http://www.kth.se/polopoly_fs/1.47075!IMSYC-66%20rule.pdf
    I have about ten students designing boats for the race :-))

    /Jakob
    ...one of the guys behind the game...
  • Re: Leg 2 IMOCA Global
    Board » Sailonline Race Committee » Races
    Hi

    As always in SOL: Changing course, maps etc in the middle of a race is generally a bad idea. Main reasons are:
    1) the communication problem. How do we make sure that we reach all boats with the info?
    2) We have very little control over when the changes become visible in the clients. Often, a clear-cache is needed (or long time).

    I vote for not changing courses etc unless absolutely vital.

    /Jakob
    ...one of the guys behind the game...
  • Re: NOAA vs SOL weather
    Board » Technical Support
    ...well you should be careful with those softwares... especially when there is a Sailplanner available for free ;-)
    ...one of the guys behind the game...
  • Re: NOAA vs SOL weather
    Board » Technical Support
    Hi all,

    You are basically all correct :-) I am the first to admit that there are many ways of doing this and that we did not spend weeks of thinking when choosing algorithm - but it works. Also (Hubert) the game winds will only correspond exactly with the GFS-forecasts when the time is exactly the time of a certain forecast frame and the point of the "observation" is exactly that of a forecast nodal point. Thus, colour coding would not be of any use at all...

    Why this attention? Is it just curiosity or weather-rounting ?

    Regards
    Jakob
    ...one of the guys behind the game...
  • Re: NOAA vs SOL weather
    Board » Technical Support
    Hi

    So, about the interpolation of weather in time and space :-) Maybe some out there is longing for a short one-liner as explanation but I am afraid there is a little more to it… Here is in short the steps we take to get an "observation" (as we call it) at an arbitrary time (called t) and location based on forecasts.

    1) Find the two forecast time steps (here called t1 and t2) surrounding the time t.
    2) In space we simply use linear interpolation (in the 2 dimensions lat/long) of the forecast-data in the 4 closest forecast-nodes in the grib-file. Since the forecast has separate fields, one for northerly wind and one for easily wind we need to treat these entities separately, in our case by using complex notation. We also need to do this for both frames t1 and t2 from step 1 which thus gives us a set of two complex-valued space-interpolated wind speeds, one at t1 and one at t2.
    3) Now we need to interpolate in time as smoothly as we can. We chose to do this using simple shape functions ensuring continuous wind speed and actually in our case continuous time derivatives.

    Now, there are naturally many ways of doing this. One draw-back of this kind of interpolation is that we loose energy. Imagine the situation with constant wind speed but rotating wind direction so that at t1 the wind is due easily and at t2 it is due westly. In our interpolation we would (falsely) get that the wind speed at the time (t1+t2)/2 would be zero.

    Also note that we do not always use the GFS model from NOAA. In particular around Sweden we have more detailed forecasts.

    Hope this helped a little.

    Regards
    Jakob
    ...one of the guys behind the game...
  • Re: OCTOBER 2010 - draft calendar
    Board » Sailonline Race Committee » Race Calendar
    Hi.

    We all remember the Irish-rock episode. The problem that time was the unauthorized use of protected brand names. From that point in time SOL has been, and will continue to be, careful and considerate in terms of naming races. However SOL is not by any means scared of racing between locations in the geography where others, IRL or virtually, also race. Until proven wrong SOL is of the opinion that it is totally ok for anyone to race "similar time-similar route" as IRL-races. No-one has ever raised any legal aspects regarding this. However I do want to point out that if SOL administrators (Godesses etc) do not see that a certain race fits the calendar it is up to the community to argue and be sugary :-)) Happy sailing /Jakob
    ...one of the guys behind the game...
  • Re: Rename boat
    Board » Technical Support
    Done :-)
    ...one of the guys behind the game...

Races

Next Race: 00d 00h 00m


Current Races:

A to A Easter Offshore Race 2020
Welcome all to SOL's fourth race in this year's twelve race SYC Championship, and to another prestigious buddy-up with RHKYC for their A to A Easter Offshore Race 2020 which is a replacement for the deferred 2020 Rolex China Sea Race. This 400nm race will take boats from Hong Kong to Pratas Reef, Pedro Blanco before finishing back in Hong Kong waters.
Race #1332
INFOby brainaid.de
J130 Particulars
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
SYCCH - SYCQ2 - SUPSOL - SYC
ALT. CLIENT:Classic
Race starts: Apr 10th 03:30 Registration Open!
New HTML5 Client GO TO RACE

Brisbane to Gladstone Yacht Race 2020


The Brisbane to Gladstone Yacht Race has been an annual event since 1949 and has become Australia’s #2 classic – 2020 marks its 72nd anniversary but due to COVID19 it will be a virtual classic only this year.
Race #1339
INFO by brainaid.de
Super Maxi 100 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
RANKING: SYC
ALT. CLIENT: Classic
All Times in UTC
Race starts: Apr 10th 01:00 Registration will open soon
New HTML5 Client GO TO RACE

Hook Island TIMED Race 2020
Welcome to Australia and the first race of Sailonline's 2020/Q2 TIMED Race Championship. We'll be racing Farr 38s some 64nm between the islands of Hook and St Bees.
RE-REGISTER HERE to race again after finishing a run.
Race #1331
INFO from brainaid.de
Farr 38 Particulars
WX Updates: 0430 / 1030 / 1630 / 2230
Ranking: TRCH – TRQ2 – SUPSOL - SYC
ALT. CLIENT:Classic
RACE CLOSE: 19 April at 2300utc
Race starts: Apr 06th 12:00 Registration Open!
New HTML5 Client GO TO RACE

Captain Bartholomew Gosnold Memorial Race 2020


Welcome to the second of three races arranged between Sailonline and SailNewport. This time we are heading out of Newport in a race around Nantucket Island in TP52s to celebrate the life of Capt. Bartholomew Gosnold who, among many other things in his short life, "named Cape Cod for the teeming fish he encountered there, and Martha’s Vineyard for his daughter."
Race #1347
INFOby brainaid.de
TP52 Particulars
WX Updates:
0245 / 0845 / 1445 / 2045
Ranking: None
ALT. CLIENT: Classic
Race starts: Apr 04th 21:00 Registration Open!
New HTML5 Client GO TO RACE

Oahu East Coast RTI Sprint
Come with us to the "Windward Side" of "The Gathering Place", O'ahu, thus named by ancient Polynesian seafarer Hawaiʻiloa in honour of his daughter, probably left behind on some distant western shore, there to find a short course of 23nm in length leaving a number of rocky volcanic crags and islands to port and starboard, and a fleet of well-preserved Frers 33 to race each other in.
Race #1334
INFO by brainaid.de
Frers 33 Particulars
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
SPRCH – SRQ2 - SUPSOL - SYC
ALT. CLIENT:Classic
RACE CLOSE: Wednesday,
April 8 at 2300 UTC.
Race starts: Apr 04th 16:00 Registration Open!
New HTML5 Client GO TO RACE

Van Isle 360 2020
Welcome back to Vancouver and the 525nm delightful course designed by SOLer fastpassage39. This is a tricky race, combining tight channels and open water which our seldom sailed and elegant Dufour 40 will love.
Race #1336
INFO by brainaid.de
Dufour 40 Particulars
WX Updates: 0430 / 1030 / 1630 / 2230
Ranking: SYC
ALT. CLIENT:Classic
Race starts: Apr 01st 17:00 Registration Open!
New HTML5 Client GO TO RACE

A3 2020- Leg 3 - Hobart to Sydney
SOL's continuing tribute to AGage is the A3 - Agage's Around Australia Series. This race is Leg 3 of a 9-race series. Not a race goes by without the name of AGage appearing somewhere in race chat. We continue our running of this tribute circumnavigation of Australia in his memory. Leg 3 is a 630nm race from Hobart to Sydney.
Race #1330
INFO by brainaid.de
First 47.7 Particulars
WX Updates: 0430 / 1030 / 1630 / 2230
Ranking: A3 - SYC
ALT. CLIENT:Classic
RACE CLOSE:Monday, 6. April at 23:00 UTC
Race starts: Mar 28th 19:00 Registration Closed
New HTML5 Client GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member bonknhoot
  2. Sailonline Yacht Club Member WRmirekd
  3. Sailonline Yacht Club Member rafa
  4. Sailonline Yacht Club Member Kipper1258
  5. Sailonline Yacht Club Member calmxy
  6. Sailonline Yacht Club Member Beliberda
  7. Sailonline Yacht Club Member Starship
  8. Sailonline Yacht Club Member batatabh
  9. Sailonline Yacht Club Member Bimmer
  10. Sailonline Yacht Club Member Go4iT

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Series

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