Radio Fax Northwood and DWD 


Following the discontinuation of Bracknell Radio Fax broadcasts, the Royal Navy enhanced its transmissions from Northwood - GYA.  This page lists the Marine content of the Northwood schedule and adds some comments.   The history and a summary of the need for Radio Fax can be found elsewhere on this site  A seprate page deals with reception problems.


Reception Northwood Northwood Schedule DWD
RadioFax Reception  
There are some dedicated equipments available but, usually, most people use a standard HF/SSB receiver and a laptop. The NASA HF3 is a very cheap set that does a good enough job for most needs although it may need more careful tuning than more expensive sets, As the future is in some doubt, it may be the most sensible buy. For software, there are several packages around such as Mscan or JVcomm.

Northwood Radio Fax - GYA

Schedule and frequencies are set out below


 

To many sailors,  this broadcast is probably more useful than either the old Bracknell GFA or the old RN Northwood GYA broadcasts.  There is emphasis on forecast information in wind vector form rather as well as isobars.

There are two significant improvements over the Bracknell broadcast -.

First, forecast charts now have wind vectors for winds of 25 kn or more. These will appear as shown here for SW 20 and N 25 knots.


 
 
 

Secondly, there are forecast charts up to 5 days ahead and available twice a day.

There are some unsatisfactory features that may get rectified in time.

First, as a power saving measure, the transmitters are switched off between charts. Thus there is no tuning signal prior to the start of a broadcast.  This will create difficulties when receiving charts around dawn and dusk since, at these times, the optimum frequency can change quickly due to rapid changes in the characteristics of the ionosphere.

Secondly, the chart headings are difficult to read. It will be necessary to refer to the schedule to know what chart is being received.

Third, because much of the output is computer generated, the lines tend to be rather thin and not so easy to see as the "old" Bracknell charts.

As already emphasised, users should remember that this is a broadcast explicitly for RN and NATO ships.  It has information on it that is clearly of a military nature and much information not at all relevant to yachtsmen and women.

To reproduce the GFA footprint, it would have  been necessary to  use the whole range of Bracknell frequencies.  GFA, Bracknell, used to use frequencies up to 14,436 kHz H24 and  18,261 kHz  by day.  The highest frequency now used by Northwood is 11086.5 KHZ.  This  limits the day time range for good reception by yachts that are unlikely to  have optimum aerial configurations.  However, an old friend - George Lipscombe - found good reception on a passage from the UK to the Azores.

The big uncertainty, of course, is how long the Navy will continue with this broadcast.  presumably, it is essentially a back up to more modern methods of chart dissemination.  the pressure must still be on for the long distance sailor and those  likely to be out of normal land line telephone contact to keep abreast of technical developments in the field of satellite communications.

NOTE - The schedule below is of those transmissions likely to be of use to leisure and professional sailors.  Some transmissions are for the use of Naval aircraft and submarines but of no interest to the sailor.

NORTHWOOD

SCHEDULE
(New schedule w.e.f 11 June 2004)

Area
: North Atlantic and Mediterranean

Frequencies

   
 2618.5 kHz
 )
HH+24
   
 4610   kHz
 )
HH+24
   
 8040   kHz
 )
HH+24
   
11086.5 kHz
 )
HH+24


Broadcast time*

Chart

Data time* on which product is based

0000/1200

Surface (MSLP) analysis (Repeat)

1800/0600

0012/1212

Surface (MSLP) prognosis T+24 (Repeat)

1800/0600

0100/1300

Schedule

  

0236/1436

Surface (MSLP) analysis

0000/1200

0300/1500

Surface (MSLP) analysis (Repeat)

0000/1200

0336/1536

Sea surface temperature (SST)

0348/1548

Gale Warning summary

  

0400/1600

Surface analysis (Repeat)

0000/1200

0436/1636

Surface (MSLP) prognosis T+24

0000/1200

0500/1700

Surface (MSLP) analysis (Repeat)

0000/1200

0512/1712

Surface (MSLP) prognosis (MSLP) T+24 (Repeat)

0000/1200

0524/1724

Surface (MSLP) prognosis T+48

0000/1200

0548/1748

Gale Warning Summary

  

0600/1800

Surface (MSLP) analysis (Repeat)

0000/1200

0612/1812

Surface (MSLP) prognosis T+24 (Repeat)

0000/1200

0724/1924

Surface (MSLP) prognosis T+48

0000/1200

0736/1936

Surface (MSLP) prognosis T+72

0000/1200

0748/1948

Surface (MSLP) prognosis T+96

0000/1200

0800/2000

Surface (MSLP) prognosis T+120

0600/1800

0824/2024

Significant surface winds (grid points) prognosis T+48

0000/1200

0836/2036

Significant surface winds (grid points) prognosis T+72

0000/1200

0848/2048

Significant surface winds (grid points) prognosis T+96

0000/1200

     

0900/2100

Surface (MSLP) analysis

0600/1800

1000/2200

Surface analysis (Repeat)

0600/1800

1012/2210

Surface (MSLP) prognosis T+24

0600/1800

1024/2224

Reduced visibility prognosis T+24

0600/1800

1100/2300

Surface (MSLP) analysis (Repeat)

0600/1800

1112/2312

Surface prognosis (MSLP) T+24 (Repeat)

0600/1800

1124/2324

Sea and swell prognosis T+24

0600/1800

1148/2348

Gale Warning Summary


*All times are UTC/GMT

Martin Stubbs' site has a link to the most recent version of the FULL schedule.


DWD Radio Fax


 

The Deutscher Wetterdienst (DWD) provides a RadioFax service as a contributioon to the GMDSS. How long this service will continue is uncertain. The technology is obsolescent and it will probably be replaced by a  satellite  based sustem within the next 5 - 10 years. Schedules are at   the DWD radio-fax broadcast schedules link. Also useful is the  NOAA Guide to world-wide radio-fax broadcasts:

 


Return to home page


Return to top of page



© Frank Singleton

6 March 2005

Update March 2007