marinheiro 352 Posted August 19, 2015 Share Posted August 19, 2015 Hi Matt, I currently have a Standard Horizon CPF300i Plotter/Sounder. It has NMEA 0183 inputs (3) and outputs (4) and can also take a video feed, which I guess could be used as a second screen from a Laptop Quote Link to post Share on other sites
rigger 47 Posted August 19, 2015 Share Posted August 19, 2015 As to the radar issue Rigger bought up - it you have a Navico radar (Lowrance/simrad/B&G, 3G 4G or BR24) then there is no magnetron! Point taken on the non magnetron radars. The point I was trying to make was do not rely on a ship's radar set to pick you up - the majority currently have magnetrons. Also from personal observation of hundreds of different ships, and who knows how many radar setups I have found a large number are poorly setup. Quote Link to post Share on other sites
Beccara 25 Posted August 19, 2015 Share Posted August 19, 2015 Just a caution: AIS can have errors - in my job I see position errors greater than 100metres - not huge - but the largest I have seen was over 10nm out of wack, that is significant and rendered the data useless. Just a question on this, AFAIK and I may very well be wrong but can't AIS only be wrong in terms of position errors if the feeding GPS signal is wrong? AIS is in effect just a basic GPS transmitter (along with other sensors for things like ROT) with a fancy slot positioning system (for class A atleast) Quote Link to post Share on other sites
rigger 47 Posted August 19, 2015 Share Posted August 19, 2015 Errors can creep in: - The antenna position. example - a 266m long ship with antenna aft above the bridge, but setup has it positioned on the bow. A 200m error in one case. - Some older GPS units do not communicate well with early UAIS units - your main nav GPS on a datum other than WGS-84, - quarter nm error on one occasion. - Manual offset on main nav GPS - error witnessed by this one was +10nm... With Class A they have to take a feed from the main GPS - they also have their own built in GPS but the external feed overides the built in one. I think the USCG highlighted the issues with reference to the GP80 linked to the UAIS FA100 - might not have those model number correct - was awhile ago. A regular caller to NZ has errors ranging from very minor to + quarter of a nm. Quote Link to post Share on other sites
erice 732 Posted September 14, 2015 Share Posted September 14, 2015 am happily running opencpn on an old netbook running xp gps position data coming from a small garmin etrex on a usb cable bought a $20? usb DVTV dongle to experiment with AIS but got stalled by complications with driver installs this step-by-step pdf has got me going again http://www.marinetraffic.com/files/DVBT_SDR_vS.pdf Quote Link to post Share on other sites
Island Time 1,239 Posted September 14, 2015 Author Share Posted September 14, 2015 erice, I have one of the usb tv dongle systems, in the office. It provides info to Marine Traffic. Station name is Gulf Harbour if anyone is interested in looking it up. It uses SDA# and AISMON software to decode the signals. Realistically it is crap. Limited range (very), unstable and therefore not reliable. An interesting toy. I am currently experimenting with a colinear co-ax antenna to see if I can make it actually useful. I really do not recommend this for anyone's boat at this point. Quote Link to post Share on other sites
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