| Author |
Message |
    
David Sheriff
Board Administrator
Username: admin
Post Number: 244
Registered: 01-2004
| | Posted on Sunday, September 14, 2008 - 09:05 am: | 
|
How Loxodromes preceded the Mercator projection.
|
David Sheriff
Board Administrator
Username: admin
Post Number: 169
Registered: 01-2004
| | Posted on Thursday, August 14, 2008 - 09:47 am: |
|
"References" as opposed to "reading material" are a menu of resources you may want to consult without being directed to read them in their entirety. Sometimes they answer logical questions which follow from course material. Sometimes they provide an opportunity to go beyond course objectives. Sometimes they are so comprehensive that you will have to search within them to find a particular answer.
Regarding navigation and collision avoidance
Chart number 1 All symbols and conventions on NOAA nautical charts are defined here. This reference is no longer in print at least partially because it is available on the web.
Home page for NOAA nautical charts The best part is they are free. Slightly inconvenient is that you must view them with software. You can buy any NOAA chart and many other charts on paper at Safe Navigation, two references down.
OceanGrafix - supplier of print-on-demand fully updated nautical charts. Also a searchable chart catalog and a free chart viewer.
Safe Navigation, a Long Beach supplier of charts and navigation paraphernalia. An OceanGrafix dealer. This link is not terribly useful, but it is what they give out.
Safe Navigation is at 129 W 5th St., Long Beach. 800-723-3628.
US Navigation Rules Online A combination of the International Rules of the Road and the Inland Rules.
As piloting, strictly speaking, is not electronic navigation except in the sense that you might use radar, I have moved the Bowditch selection out of required reading.
Bowditch Chapter 8, Piloting In the age of GPS and electronic charts, does piloting still have a place? "Piloting involves navigating a vessel through restricted waters" as the first sentence of this Navigational Bible states. Pages 119-135 describe how a Navy vessel is piloted. It should be obvious what parts are applicable to a few people piloting a sailboat and what are not. I find this reference helpful in that it examines each task we do in piloting in minute detail. The functions performed by the entire piloting team as described are done by just a few people on a small boat and they may be done informally. However, you still do all these functions even though you might not think of it that way. Do we pick a place to anchor and then slow down and perhaps reverse slightly before dropping the anchor? Yes. Do we plot it out in the detail described? No, but we still think about it in the same terms. We check our engine, watch the depth, mentally plot bearings to navigational aids, consult a chart, and we think through what we are going to do before we do it. Do we still need piloting skills? If you think not, be sure to read the Perugini reference too. Murphy's law still comes out to bite us. If we do not have redundant methods of accomplishing our objective, we can end up on the rocks. |
David Sheriff
Board Administrator
Username: admin
Post Number: 186
Registered: 01-2004
| | Posted on Sunday, August 24, 2008 - 06:03 pm: |
|
Regarding GPS and ECS (Electronic Charting Systems)
This next link has been superseded- see below
NOAA Raster Navigational Charts There is a free online viewer here and links to seven free "trial" programs that may be used for viewing charts. The Rose Point program is one of the chart viewers we will be using in class.
Ted has found a better link to the charts. "I prefer to use the Maptech site to do the same thing to get exactly the same charts. You can download all charts by Maptech region (Southern CA coast to Ensenada is region 12) in one shot. You will receive an email with a link to their site, and you download a single file, in which all the charts have been compiled and compressed. You open the downloaded file and are asked where you would like the uncompressed charts stored. You then tell your chartplotter that you have new charts, and to register them (the exact process depends on the chartplotter software you use)."
To get started to to: Here "Some time ago I uploaded a sample email containing information regarding the process that gets sent to you after you pick the charts you want. You can find it: Here"
The compass
Manual for a fluxgate compass with NMEA 0183 output Also contains a good explanation on how to interface to a 0183 signal electronically.
how a fluxgate works OK, if you just have to know exactly how they work, here's an explanation from the experts.
Integrate a GPS receiver with an electronic chart system and you have a "chartplotter."
The Lowrance website. One of the cool things Lowrance does, from our class point of view, is make almost fully functional product emulators available for download from their website. If you go back and forth between product and emulator pages (in the download section) you can pick the device you want to test drive. I've been running the 9200C chartplotter for an hour now and it seems to work pretty well. There is enough of an ocean chart off LA/OC to work with and detailed sample charts can be downloaded for some other areas. Several companies have bulked-up their product offerings by buying smaller companies or developing new lines of equipment. Lowrance joins Garmin and Simrad in this category to become more serious full-line competitors to Furuno and Raymarine.
Oops, I'm still 2 hours out of Avalon on the 9200C and it's time to tack.
Inter-device communications
The RS-232 serial interface. In typical Wikipedia style, this is probably more than you will ever want to know about RS-232 all in one place.
|
David Sheriff
Board Administrator
Username: admin
Post Number: 230
Registered: 01-2004
| | Posted on Friday, September 05, 2008 - 11:51 am: |
|
Position, Navigation and Timing: GPS and LORAN
Wikipedia's comprehensive article on the GPS system. Beyond understanding the basic system, you should take away an appreciation of how the system continues to evolve, who is pushing that evolution, what SA is and why the military no longer needs it, the source of errors in GPS positions, how these errors are partially compensated and just how much capability is built into the system that we mariners do not yet access. You might also figure out why Homeland Security will be continuing and upgrading the "old" Loran system.
If you glaze over and skim past the math you will still get a lot out of this reference. Pay attention to what the math accomplishes, not how it works.
GPS Maniac may be the best independent GPS product review site. Eric Gakstatter spent the past seventeen years in the GPS survey/mapping industry using many brands of GPS equipment and software. His first ten years in GPS were spent as a product manager and the last seven years as a GPS user and consultant. He is a non-partisan advocate for the GPS user community and also contributes product reviews and maintains a blog at this link.
Magellan GPS Product Finder Magellan is one of the few competitors to Garmin in handheld GPS products. I have several Magellan GPSs, but I like the very oldest one the best. Here's their website for your information.
A company called DeLorme also makes handheld GPS that seem to be designed for high-end land use and accommodate GIS data. For marine handhelds, various versions of Garmin's GPS76 seem to be the big dogs.
Here's a technical and feature comparison of handheld GPS units from 2003, not that a lot has changed since then. Courtesy of Pocket GPS World
Crossrate Technology has pioneered combination GPS / eLoran receivers I spoke with Zach Conover, president, CEO and founder of Crossrate on September 5th. Zach had a career with the Coast Guard culminating as the Configuration Manager for the North American Loran System. In this post he oversaw all field operations and testing for the Loran system
Crossrate's device is not yet on the market, but it's close. The device combines both loran and GPS signals and outputs data in NMEA 0183. A NMEA 2000 model is under development. Because of the nature of the device's "H-field" antenna, they can also resolve heading based on the Loran signal to within one degree. The entire device is enclosed in a package designed to mount on top of a standard 1 inch pole much like a GPS receiver, except that the "eLGPS 1110" is about 7 inches in diameter. Conover will be at the NMEA convention in San Diego in Early October, where I expect to talk with him at more length.
The International Loran Association ILA is an organization of loran experts who published numerous technical papers over the years. ILA is finally seeing it's positions becoming adopted internationally. The site contains an excellent reference section on everything Loran. |
David Sheriff
Board Administrator
Username: admin
Post Number: 184
Registered: 01-2004
| | Posted on Sunday, August 24, 2008 - 05:57 pm: |
|
Periodicals, Books and Organizations
Panbo, The Marine Electronics Weblog If you spent your days mostly playing with new marine technology and were influential enough that manufacturers sent you free samples of their latest gear, Panbo is the sort of blog you would write. I read it. You could do worse.
Practical Sailor Practical Sailor is the marine equivalent of Consumer's Reports. The monthly gear evaluation magazine does not accept advertising. In their view this spares them the taint of commercial bias. I have subscribed for years. While not necessarily state-of-the-art scientifically rigorous, the magazine conducts reasonable tests and picks both performance and "best value" winners. There is room for disagreement occasionally with their methods, and they are more than a little touchy about criticism of those methods. However, I rarely buy anything, particularly outside my area of expertise, without looking it up in Practical Sailor.
Professional Mariner Sometimes it appears that the MST program mostly prepares people to sail their recreational boats better on the weekend. It does that, but it also prepares students for professional maritime careers. Students with this objective should be reading this magazine and others like it posted nearby.
The online version of Maritime Reporter and Engineering News
The Daily Shipping News (and not the book of a similar title)
The International Maritime Organization The Convention establishing the International Maritime Organization (IMO) was adopted in Geneva in 1948 and IMO first met in 1959. IMO's main task has been to develop and maintain a comprehensive regulatory framework for shipping and its remit today includes safety, environmental concerns, legal matters, technical co-operation, maritime security and the efficiency of shipping.
A specialized agency of the United Nations with 167 Member States and three Associate Members, IMO is based in the United Kingdom with around 300 international staff.
This is an extraordinarily good resource!
Click "About IMO" and then "SOLAS". The Titanic disaster of 1912 spawned the first international safety of life at sea - SOLAS - convention, still the most important treaty addressing maritime safety. |
David Sheriff
Board Administrator
Username: admin
Post Number: 183
Registered: 01-2004
| | Posted on Sunday, August 24, 2008 - 05:55 pm: |
|
Regarding Sounders and Sonar
Lowrance Broadband Sounder video. This YouTube offering is typical of the way vendors are beginning to commercialize YouTube. You have to filter your way through the commercial weeds in this video, but the sounder is being written up highly in the marine technical press. By using DSP, digital signal processing, the device can operate with existing transducers at low power and produce pretty incredible images with very little clutter. When I see stuff like this (and commercial forward-looking sonar) I fear for the fish.
Were Lamarckian evolution true (in a world of modern fishfinders) and were I a fish, I would fervently wish for some mechanism to control my buoyancy other than a swim bladder.
Fishfinder considerations This is a course on navigation, not fishing. Nevertheless, many people equip their boats with sophisticated sounders to find fish and only incidentally to navigate. This article explores how a fishfinder finds fish.
|
David Sheriff
Board Administrator
Username: admin
Post Number: 185
Registered: 01-2004
| | Posted on Sunday, August 24, 2008 - 05:58 pm: |
|
Radar |
David Sheriff
Board Administrator
Username: admin
Post Number: 182
Registered: 01-2004
| | Posted on Sunday, August 24, 2008 - 05:46 pm: |
|
The Integrated Bridge
Marine Technologies LLC These people make some of the sweetest ship bridges in the world. They specialize in bridges for dynamic positioning craft.
Maretron These guys specialize in NMEA 2000 hardware. They have just come out with a NMEA 2000 display with buttons. I'm not sure yet how they deal with software. Existing chartplotter vendors have a sweet profit-enhancement tool in reselling free government electronic charts translated into proprietary formats. As soon as someone decouples chartplotter hardware from chartplotter software these pigs are getting their due. Perhaps this Maretron display is a first step. |
|
Closed: New threads not accepted on this page
loxodrome math