Navigation the Rite Way.. or Is GPS Reliable???

[s/v Faith]

This topic has been around for a while, and these concerns are nothing new.

  Anyone with any knowledge of or background in electronics knows that things CAN and DO fail. 

Here is a story published in the 'Guardian' titled  GPS system 'close to breakdown': Network of satellites could begin to fail as early as 2010

  Just posting it here as a reminder not to grow too attached to these miracle navigation aids.

Here is a short excerpt from the article in case the link goes dead;

It has become one of the staples of modern, hi-tech life: using satellite navigation tools built into your car or mobile phone to find your way from A to B. But experts have warned that the system may be close to breakdown.

US government officials are concerned that the quality of the Global Positioning System (GPS) could begin to deteriorate as early as next year, resulting in regular blackouts and failures – or even dishing out inaccurate directions to millions of people worldwide.

The warning centres on the network of GPS satellites that constantly orbit the planet and beam signals back to the ground that help pinpoint your position on the Earth's surface.

The satellites are overseen by the US Air Force, which has maintained the GPS network since the early 1990s. According to a study by the US government accountability office (GAO), mismanagement and a lack of investment means that some of the crucial GPS satellites could begin to fail as early as next year....

[Captain Smollett]

Oh noes, you mean the miracle of GPS is not transcendental?

Ok

By the way, I'm getting $75 a head teaching celestial to those that realize this basic fact.

[Lynx]

GPS is more reliable that the old way for me. I find that in the morning and at dusk and at high noon the GPS is off 50 to 100 feet. The water changes to much to relly on it 100%. You need to know both.

Other things can cause problems as well.

[rtbates]

Taking it a step further, a recent circumnavigator used absolutely NOTHING. No compass, no charts, nothing, EXCEPT the stars... It helped, I'm sure, that he was/is an astronomy professor.

[Amgine]

::shrug:: I've been doing a touch of reading on the various current and developing satellite navigation systems. GPS3 is running behind schedule, but you know - there is already one other system that's also being renovated and upgraded, and is expected to be back to 100% functionality by the end of this year: GLONASS. That's the old Russian built system, now part of a new Indian/Russian space alliance system. France's DORIS system is still available, but it's accuracy is less than the current GPS and I'm not aware of any retail-level receivers.

Plus there are at least two new systems building out, the EU's Galileo and China's Compass, both of which are expected to be operational by 2013 (Compass will begin as regionally operative, with full global build-out by 2020.) India, South Korea, and Japan also have domestic systems in development.

So, I expect satellite nav systems are a stable and permanent element of marine navigation.

There plans available online to build your own GLONASS/GPS receiver (2), and at least one company has a commercial offering. Galileo has been deliberately designed to allow current GPS receivers to use it's open signal's dramatically greater accuracy (<1m). My personal opinion is multi-system receivers will become the norm from manufacturers sometime after 2010, but in a roll-out designed to make all the current receivers obsolete of course.

It's certainly possible to sail anywhere without any form of satellite navigation, and sailors would likely be better navigators for the experience. But not because the satellite's are going to go away, or even be at risk of going away.

[TJim]

That doesn't surprise  me. I did 2 joint tours with the Air Farce in the 60's.  They couldn't fix anything or do anything right then either. TJim

[s/v Faith]

Today is to be the day LORAN is turned off forever.

[j d]

just saw this link on another forum today. Thought you might like the article.

http://news.bbc.co.uk/2/hi/science/nature/8494225.stm

[Captain Smollett]

Kinda sad in a way to see Loran go.  It makes me wonder if any of us will see the last day of GPS when the Next Big Thing takes over and IT is no longer maintained/deemed 'useful.'

Interesting that it comes this week.  Just two days ago, I was chatting with a friend here who, with her husband and now 15 year old son, have traveled the world by 'small boat'  (a Nicholson 31).  They've crossed the Canal several times, been to NZ, through the Pac, across the Atlantic, etc.

That's just background, though..the interesting (and on-topic) part of the story was their 300-ish mile circle on the Amazon in the Belem region.  There were, of course, no channel markers and what charts there were were woefully out of date.

How did they navigate?

Well, you could only sail a couple of hours each day before the adverse current took over.  When that happened, they anchored.  The rest of the day was spent 'charting' the next day's route with the dinghy - and a sounding pole.

"How did you mark your turns?" says I.  "Did you drop buoys?  Or, did you have a handheld GPS you marked waypoints in?"

"No, we had none of that," came her South African reply.

"Oh, I get it; you got an eyeball on that tree, that shack over there...is that it?"

"Oh yes.  That's exactly what we did.  We noted what we could see when we needed to make a turn."

Eyeball pilotage - still reliable after a couple thousand years of sea navigation and, I assume, it will remain so for a couple thousand more.

(I'm trying to get her to join SailFar to share some more of their nearly 20 years of experiences in the Sailing Stories section....)

[AdriftAtSea]

They're also called ranges, and very common in many harbors.

[Captain Smollett]

No, she was not talking about ranges.

She was talking about cross bearings.  Looking at multiple objects on shore and recording bearings.

There were no aids to navigation - no pilings, no man-made aids at all.

And the actual channel was very different from that shown on the chart.

How would ranges help in a situation where the bottom shifted constantly?  What is a range today won't be next week.

They literally felt their way forward with the dingy and recorded cross bearings at the turns.  Just like the old square riggers used to do when charts were unreliable.

I thought it was cool.

The other thing she mentioned was "waiting for a local to come by on his canoe" and asking him where the bottom is today.

[Cmdr Pete]

Kudos to the South Africans for navigating into uncharted waters.

I'm sure we all use similar techniques in everyday sailing--lining things up. This can be especially useful when compensating for current. If you're on the right course, you can line up two objects  (say a buoy ahead and an object behind it on land) and keep them in line.

Or else I might just keep looking ahead and behind, keeping the next buoy on my bow and the last buoy on my stern. Simple eyeball navigation.

Reminds me of a time years ago. I had navigated down a narrow unmarked channel to a little village. I was talking to an old-timer at the dock about how I was going to sail a reciprical course back out. He tells me "See that island out there with the big clump of trees? You keep them trees on your bow and this dock on your stern."

A fairly typical way to navigate.

I won't be going to the Amazon until they get buoys and SeaTow.

Sometimes I'll use my little boat as a research and exploration vessel for my big boat. I use a handheld depthsounder to find the deep water for a future trip with the big boat. I should probably use a pole instead, since I can't get a reading off the depthsounder half the time.

[Captain Smollett]

I use a handheld depthsounder to find the deep water for a future trip with the big boat. I should probably use a pole instead, since I can't get a reading off the depthsounder half the time.

LOL.  The ONE thing she said she would not leave without 'next time' is a depth sounder for the dink.  The pole got very old.

I still like Charlie and Laura's fishing pole/float method.  The float is tied on at the "no go" depth with a  weight on the end heavy enough to pull the float under.  If she floats, the water is less than the "no go" depth - if it sinks, you are good to go.

I HAVE used a pole (my boat hook actually) to sound a channel from the dingy ... but I was already aground and wanted to find the way out.   :P

[newt]

Back to the original posting. I was talking to a military satellite specialist the other day. I asked him did he ever see the GPS system go wacko. He  laughed and said- "those civilian things you use? I've seen them inaccurate due to cloud cover"  I thought that was interesting that we depend on them to land planes in cloud cover....

[mrb]

I have a friend who built his own air plane, nice two seat-er.  He put a gps in it, the main diff. is in the antenna (or reciever) and of course the computer.  The more you pay the better the receiver.  I would imagine a $1,000  unit is going to give better service than a $100 unit. Melvin

[newt]

What about the ones we use for our boats? Are the expensive ones using the military Algorithm?  I bet not. Just food for thought. BTW- that makes sense about the planes. It seems that whenever our pilot goes through the fog with one that the landing is kinda rough, but it just might be my imagination.

[mrb]

Sorry guys nothing is 100% safe.  Sometimes instruments and human judgment just malfunction.  As things go gps are only a tool among many that any sailor or pilot has at his disposal.  Don't sweat the what ifs and enjoy the what ises(new word of the week  ISES).
   

[saxon]

I've got a sextant, and I use it but...
Three days of this day and night,  closing a rocky coast from an ocean crossing, and there's gale forecast thrown in for good measure then it's ...
"I love you Mrs Garmin".. :D  :D   :D

[newt]

I agree- navigation is everything from looking out of the cockpit to getting a GPS fix. In reality the question should be "Should you rely on any one source of navigation information??" Heck, I am thinking about getting a cheap AM radio with a directional antenna. I am glad that we have GPS's today, but perhaps the name of the game should be how many ways can I navigate to the port?

[s/v Faith]

I just received a Freiberger sextant.  ;D



  What a wonderful gift!  I will probably be selling one of my Davis sextants soon.