Help idenfity this Data Mode? Interference?

[WrongwayCorrigan]

Hello all,

I am hoping an SWLer here will be able to identify the transmission I monitored in the link below. Is this a test of a data mode or could it be local interference? The recording will begin with the radio tuned at 4520 kHz SSB. The radio is then tuned incrementally up to 4552 kHz so you can hear how the signal is heard across several frequencies.

Receiver: Grundig G6 Aviator
Anntenna: Telescoping Rod
Place of Reception: Northeastern United States
Date: 07/17/2010
Time: 0630 UTC
Frequency: 4520 kHz to 4552 kHz SSB

http://www.zshare.net/audio/7840650813a21fca/

[Seamus]

I believe that's one of the variants of over-the-horizon radar. 
Until fairly recently, I had only heard it on recordings from locations in western- and south-central US.  I've recently started to hear it from time to time on my own radio here in upstate South Carolina, so I presume that whatever system is producing it, they have recently expanded its use.

For what it's worth, the radio here in an Icom IC-718, with a 400-foot wire at about 40 feet, with an apparent north-south bias to the pattern.

[SW-J]

Per http://en.wikipedia.org/wiki/Wave_radar possibly http://www.codar.com/

See http://www.codar.com/intro_hf_radar.shtml  "The Unique Nature of HF Radar"

In the FAQ section http://www.codar.com/intro_faqs.shtml they mention some specifics like range and frequency:

Q: How far out will it measure?

A: The range of the SeaSonde depends upon a number of environmental factors (i.e., external noise, significant waveheight, current speeds), location of radar (such as proximity to water, nearby obstructions) and SeaSonde operating frequency (the lower the frequency, the longer the range).

Typical ranges are listed here:

For 4-6 MHz: 160-220 km average during daytime. (With 4-6 MHz only, the range is reduced significantly at night as external background noise rises.

- - - - - - - - - - - - - - - - - - -

RADAR signal received in north central Texas on modest gear: http://www.youtube.com/watch?v=c-T4rTBwpJA

[WrongwayCorrigan]

Thanks for the quick ID on this HF radar signal. SW-J your links were helpful to describe this signal in detail. I live fairly close to the Atlantic Ocean, so they must be monitoring currents out there. This is the first time I caught radar of any type. I am hoping to catch more in the future.


 

[SW-J]

Thanks for the quick ID on this HF radar signal. SW-J your links were helpful to describe this signal in detail. I live fairly close to the Atlantic Ocean, so they must be monitoring currents out there. This is the first time I caught radar of any type. I am hoping to catch more in the future.

You're welcome ... in case anybody else is wondering where these CODAR (they call them "SeaSondes' for "Sea Sounders" I suppose) systems are located/originate signal-wise, there is s pretty good map on the CODAR website here: http://www.codar.com/seasonde_world_locations.shtml



Additional: Transmit Power levels and specific frequency range within this detailed product brochure:

http://www.codar.com/images/products/SeaSonde/1A-SeaSonde_v2_20100331.pdf

[SW-J]

While surfing for other info, came across a little more info on:

Ocean Motion - High Frequency Radar: http://oceanmotion.org/html/gatheringdata/hfradar.htm

HF Radar Derived Surface Current Data:

North America - http://cordc.ucsd.edu/projects/mapping/maps/

Gulf of Mexico - http://www.cengoos.org/

[WrongwayCorrigan]

They are making such a racket on my shortwave...at least they are decent enough to allow the public to view the data.

[cmradio]

More:

http://www.weatheroffice.gc.ca/model_forecast/wave_e.html

Peace!

[PresentedIn4D]

In relation  to the previous posts, yes, it is CODAR, and I believe it is around New York Harbor.

FAIL, CODAR, not CONAR, I was thinking of Sonar. Disregard that.

[SW-J]

In relation  to the previous posts, yes, it is CONAR, and I believe it is around New York Harbor.

Conar?  -- http://www.google.com/search?client=opera&rls=en&q=conar&sourceid=opera&ie=utf-8&oe=utf-8

Listed sites in the northeast for CODAR sites (per link to map previously posted) show:

• Gulf of Maine
• Cape Cod
• Nantucket
• Long Island Sound
• New York Harbor
• New Jersey
• Delaware Bay
• Virginia Beach

Sites per map - http://www.codar.com/seasonde_world_locations.shtml

Whether this map is entirely accurate, that I don't know ...


Another site that allows Google-style zooming-in to see the SeaSonde/RADAR/CODAR coverage seems to confirm the above map:

  http://cordc.ucsd.edu/projects/mapping/maps/

Looks like solid coverage from the tip of Long Island down past Virginia Beach.

Screen grab from that page showing coverage:

[WrongwayCorrigan]

The Coastal Observing Research and Development Center map provides station locations and their frequencies.

I am not hearing anything when I tune to the frequencies of stations closest to my QTH:

Stehli Beach, NY  (STLI) Center Frequency: 26.19 MHz

Breezy Point  (BRZY) Center Frequency: 25.25 MHz

Tonight I observed what may be CODAR sweeps from two stations on 4535 kHz:

http://www.zshare.net/audio/79591240a622e602/