24 August 2014

Portuguese Navy & CTA NATO on HF (STANAG-4285)

(always-under-revision post)
 The Portuguese Navy (Portuguese: Marinha Portuguesa, also known as Marinha de Guerra Portuguesa or as Armada Portuguesa) is the naval branch of the Portuguese Armed Forces which, in cooperation and integrated with the other branches of the Portuguese military, is charged with the military defence of Portugal. The Portuguese Navy also participates in missions related with international compromises assumed by Portugal (mainly with NATO), as well as missions of civil interest.
Today, the Portuguese Navy assumes a dual role capacity: Naval combat missions to assure Portugal's sovereignty and international commitments, and coast guard operations in its territorial waters and areas of influence.
The Portuguese Navy, tracing back to the 12th century, is the oldest continuously serving navy in the world!

Portugal became a charter member of NATO in 1949; it is an active member of the Alliance, and Portuguese forces participate in NATO operations in Afghanistan and Kosovo. Under the 1995 U.S.-Portugal Agreement on Cooperation and Defense, Lajes Field in the Azores serves as a logistics hub for U.S. Transportation Command, U.S. European Command and NATO allies. In 2012, Naval Striking and Support Forces NATO (STRIKFORNATO) transferred from Italy to Portugal. STRIKFORNATO is NATO’s premier maritime battle staff and the Alliance’s primary link for integrating U.S. maritime forces into NATO operations. Portugal also has been a strong partner in the fight against terrorism and drug-trafficking.

CTA is the callsign used in HF/STANAG-4285, they usually use ISB mode [1] , i.e. the encrypted channel on USB and CARB messages (clear) on LSB.

CTA14 STANAG-4285/ISB spectrum

The CARBs  sent by CTA, as seen, expose the time (UTC) of the transmitted frame just at the beginning of every row:


reported sites
Monsanto (Lisbon) *
Oeiras (Lisbon)

* CTA its located in Serra do Monsanto, in Lisbon and not in Monsanto municipaly

reported frequencies SATANAG-4285/LSB/600L/5N1
02572.5 CTA02
04306.0 CTA04
64595.0 CTA06
08701.0 CTA08
12704.5 CTA12
14631.0 CTA14
17217.1 CTA17 [?]
19743.0 CTA19 [?]
22210.0 CTA22


[1] http://i56578-swl.blogspot.it/2014/09/isb-independent-side-band-transmissions.html

All information in this document was submitted by independent radio monitors or has been obtained from public available sources and public sites on the web. Wherever data was obtained via the web or elsewhere, references and/or links to these sources have been noted.


  1. Hi António.

    Very good post.

    Indeed CTA has moving location along time. Its the main station of PoNavy. Presently its located outside Lisbon,in Penalva (tx site) and Fonte da Telha (rx site) after Monsanto Naval Radio Station Nunes Ribeiro close. the location of this sites are: tx: 38°36'11.36"N 9° 1'49.54"W rx: 38°33'21.64"N 9°10'49.90"W. This two stations are linked by microwave and fiber cable network as well remain Navy and Mil networks (SICOM net).

    73's from Lisbon, PT
    aka pmaf
    swl CT01135
    ham CS7ACM

  2. Thanks Paulo for the comments, very apreciated indeed.