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How GPS Is Killing Lighthouses
sakshale writes "Spiegel Online has an article about the impact of GPS systems on Lighthouses.
They claim that the popularity of the satellite-based global positioning system has led to the closure of lighthouses along the German coast." As the article says, "critics question whether the new system is reliable and safe enough to warrant the closure of these historical beacons of safety."
Radar is common on big boats, but for small personal boats, it would be quite expensive. GPS, on the other hand, is so cheap that almost everybody can afford it.
... is what Europe came up with, as an answer to your question.
l ileo/index_en.htm
...but the yanks are not happy....
http://www.esa.int/export/esaNA/galileo.html
http://europa.eu.int/comm/dgs/energy_transport/ga
China seems to agree
Mabye if the boat is big enough, but seriously, nothing electronic can be relied upon after being at sea for a while. Salt water doesn't like electronics, and the feeling seems mutual.
I have heard stories of old sea dogs who have sailed the pacific, starting out with all of the electronics, and equipment necessary (including an iron genoa) and by the time they made it across, were relying on sextants, compasses, and sail power.
Just because it works well on land, it don't mean it will last at sea. Smaller privately run yachts (not weekenders) often cannot afford the redundancy required to ensure that all this stuff will work all the time.
Paper can't crash.
The prudent mariner will not rely solely on any single aid to navigation.
Natianiel Bowditch (as best as I can recall the quote)
Among many other reasons for retaining fixed aids to navigation, the GPS system uses the WGS-84 datum. Many charts, in particular many harbor charts, still use local datam references.
Check with the former Commanding Officer and Navigator of the USS LaMoure County for their opinion regarding over-reliance on GPS positions with respect to local chart datums.
Visual and radar piloting have the benefit of being independent of the local coordinate system. Visual aids to navigation, in particular, may seem to be "obsolete" but they are wonderfully helpful in real world piloting situations.
Been there, done that, didn't get relieved for cause.
Trusted by cats.
You lose big Karma points for posting a Snopes story as truth.
Snopes... if it sounds too good or too funny to be true, you should probably check Snopes. Otherwise, those of us who have will mercilessly mock you.
You're not thinking small enough. I have been on sailboats that are 22 feet long and some that are 42 feet long. They do NOT have radar. Loran was installed (but it isn't very accurate). GPS is finialy cheap enough, but not always available (requires bateries that can die). Our sailboat had a small gas motor. We had no power source other than bateries on hte smaller boats. Radar is still far and few between on them and will not pick up shallow watters or wrecks. Some form of light is still an advantage in storms where GPS is either un available or too hard to compare to a chart of the area. Lighthoses and buoies are still the best way to go for the smaller boats.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
Surveyors can let a GPS "integrate" and use other techniques that don't work on a moving boat.
Also in many parts of the world knowing your exact possition to within meters is not as good as it sound because the charts are not so good. For example if the big rock is charted 1/2 mile ast of where it really is. This is common. Radars and lighthouses will still be needed for a long time.
Every book and navigation class will tell you to NEVER depend on only one source of navigation data. Always use at least two and cross check.
I typically use simple techniques from the pre-electronic era to comfirm the GPS. I've punch ed in a wrong number on the GPS and would have gone off in a totally wrong direction
Was that using Standard Positioning Service (SPS) or Precise Positioning Service (PPS)? The SPS is used by both military and civilian. Anyone who can purchase a $100 receiver can use it to detect their location within an accuracy of 100 meters (95 percent) horizontally and 156 meters (95 percent) vertically.
;)
The PPS is used by the military and users authorized by the U.S. P(Y) code. Not anyone can use this one. It provides provides a predictable positioning accuracy of at least 22 meters (95 percent) horizontally and 27.7 meters vertically. Not to mention that most PPS GPS devices are hard to come by. PPS is typically used in military, aviation, and marine usage.
The only way I can figure you got ~1mm accuracy is if you used a ground station as a known point of reference to correct the skew. Either that or your triangulation is wrong
GPS also uses, I believe, up to twelve satellites at a time to improve accuracy. Very rarely do they only use three satellites to obtain its coordinates.
Link
I'm a virgo and on Slashdot. Coincidence? Yes.
They already do this, not with light houses because there's no point really, but its called DGPS, Differential GPS. The Coast Guard operates it.
Most likely not. More likely, the errors you saw were caused by deficiencies that are common to cheap, commercially produced receivers that you buy at the local sporting goods store.
In any case, during disposal ops, the NAV mission broadcasts are switched off. That is, there is no broadcast containing anything that your handheld would use to compute position-velocity states. In general, de-orbits are planned events inwhich the health bits of the satellite in question are set appropriately. You receiver is programmed to ignore satellites that have poor health status.
Calculating position and velocity is a function of your receiver. Your receiver has a software filter that is very finicky. Due to one or more errors (insufficient/poor data to provide a good convergence, a local receiver clock drift that was unaccounted for, etc.) you probably got a bad solution.
In general, better receivers do not have these deficiencies. Nicer receivers have better antennas, more stable local clocks, better Kalman filter implementations, better environmental corrections algorithms (multipath, ionospherics), etc. Most seaworthy ships have nicer receivers than you or I purchase. Additionally ships generally keep their receivers on continuously giving them better previous state data to feed into their Kalman filter.
Don't generalize the problems encountered by small receivers to those of more expensive, professional receivers.
If anything, you receiver should not have even been reporting 500 km/h. It really should have been reporting a problem converging on a good solution.
The use of cellphones for marine comms is certainly NOT becoming the norm. Calling 911 on your cellphone if your boat is in trouble is the worst thing you can do. A marine radio on the energency channel is more likely to get several nearby boats, AND the Coast Guard, all in one shot. Also allows them to triangulate your position using off-the-shelf RF direction finders. Ask any coastie or freighter/tanker captain/crew, they prefer marine radio.
And it's a shame the US threatened to shoot down [spacedaily.com] the alternative european/asian Galileo system if the US military couldn't have the right to shut the new system down when it wanted
Alright, that phrasing's just a bit overdone. The US didn't threaten to just shoot it down arbitrarily, they just said they might have to if it were used by a foreign power that was at war with the US.
You know what the "*" behind the USS CORAL SEA means?
*Note: USS Coral Sea (CV 43) was decommissioned and scrapped 2 July 1993. Other ships' names appearing have been USS Missouri (BB 63) which was decommissioned on 31 March 1992 and USS Nimitz (CVN 68) which is an active ship.
Not true in the case of Loran C. It is now widely understood that not only is GPS at the mercy of its US military owners who can switch the signal off at any time, but that the GPS signal can be interfered with locally (a radius of 50 - 100 km perhaps).
Loran C is being proposed as a full back-up system to GPS in the light of these issues - particularily the interference problem. Currently, such an attack in, say, the English Channel would cause big time chaos.
The European Galileo system, when operative, will not provide an alternative back-up as it will be vulnerable to the same kind of interference attack.
I don't think so. Radar is great for finding things like metal radar reflectors on some Coast Guard buoys, steel boats, high rise buildings, and steep cliffs. Low lying land is nearly or totally invisible to radar, especially if there is any rain or rough seas. Radar will obviously not show outlying UNDERWATER obstacles either. Besides for all that, most boats DON'T HAVE IT.