Cool.. I think its very impressing.. The GPS have to be more accurate than the comersial ones, dont it?
Hi Redbeard,
It is possible to operate in DP with a normal GPS, however this would put undue wear and tear on your main engines and propulsion units as the signal jumps around alot and the DP system constantly will be "hunting" the setpoint.
As chouby-20 suggests there are other position reference systems; however GPS can be corrected with a Differential signal to improve the accuracy of the GPS signal and tighten up it's footprint. Depending on how much an operator wants to pay you can get accuracy into the cm range like Fugro's SDGPS service, but this kind of accuracy level is not necessary for DP operations, regular DGPS in the 1-5m accuracy is good enough.
Other position reference systems include; Acoustics(Sound ranging from beacons on the bottom), Fanbeam (close range laser range/bearing relative to reflector), Artemis (slightly longer radar ranging relative to scanner), Radius (A new microwave system by Kongsberg sort of like Artemis), Taunt-wire (like a plumb-line off the bottom), and a couple others. Depending on the Class of DP operation you are conducting you would use a combination of these position reference systems.
Sorry if this is a little off the Stern Thruster Discussion.
Cheers,
Larse
some interesting links for this topic;
General Principles - http://www.imca-int.com/divisions/marine/reference/intro04.html
HydroAcoustics - http://www.km.kongsberg.com/ks/web/nokbg0240.nsf/AllWeb/BCFCB4C4F48BD12CC1256A7E0032FD83?OpenDocument
SDGPS - http://www.skyfix.com/fugro/skyfixxp/skyfixxp_home.cfm
Radius - http://www.km.kongsberg.com/KS/WEB/NOKBG0240.nsf/AllWeb/57E47945903AB766C12570F3003061A8?OpenDocument
Fanbeam - http://www.mdl.co.uk/dynamic_systems/fanbeam-laser-radar/index.html
