Electronic changes

The world of electronic charting has been changing rapidly over the last few years, and it does not look like it will stop anytime soon.

Vector charts, in particular, are hot. Last year Nobeltec introduced the first U.S. PC navigation system with vector charts, and sold three times its projected volume. C-Map and Navionics continue to add detail and functionality to their wide base of cartridge-based vector charts. Garmin and Lowrance now offer inexpensive PC route planning and rudimentary vector map databases for uploading to their low-end plotters. Meanwhile, hydrographic offices (HOs) around the world are working to vectorize their original cartography. Of particular interest is the massive database created by the U.S. National Mapping and Information Agency (NIMA), which may be offered to the public this year. NOAA may also offer a limited but deeply researched set of vector harbor charts.

With the move toward vector cartography underway, it’s valuable to consider the whole ecology of chart production. Data is created and maintained by national HOs working with other government entities like coast guards and navies; these days it’s generally kept in the form of digital pixel imagery. It may well be layered – and the cartographer may have numerous software tools to aid in creating or changing layer items – but each line, symbol and word is essentially drawn in place.

When the Coast Guard moves a buoy it notifies NOAA with new coordinates, and a cartographer goes to the aid layers of the variously scaled charts and moves the buoy symbol. When it’s time to publish a new edition of the paper or digital raster chart, the appropriate layers are output as colored dots on printer’s film or into a CD file. Good raster charts can also be made by third parties with large scanners and good image-processing software.

Years ago, big military organizations realized the utility of vectorizing all sorts of map, chart, and other data. If you turn lines into strings of geo-coordinates and points into database fields with any sort of information attachable, then sophisticated electronics can create an almost infinite variety of displays for navigation, or targeting, or espionage, etc. We can only imagine the richness of data visible inside the command center of a missile frigate.

On more familiar level, consider the humble sounding. In a paper or raster chart world, a sounding is just some dots shaped like a number; the navigator must scan all in his path for those relevant to his vessel’s draft, perhaps having to convert on the fly to a more familiar unit of measure. In the vector world, a sounding is a real number that knows its unit of measure and its geoposition. The display software can compute all sorts of ways to use it. Hence, a vector chart system can sound an alarm before you move into shallow water, convert soundings into any unit desired, turn and resize the sounding as you rotate and zoom the chart, even advise you as you lay down course lines.

The same vector intelligence could, and will eventually, apply to chart making. One day that buoy position change will be zapped from ship to HO, automatically updating the appropriate database; the buoy will slide across the cartographer’s vector displays; and the change will be immediately available for printing, or packaging into electronic charts, or as an update via numerous channels. That’s the dream; the reality is a lot less efficient. In short, the future is vectorized, but it’s not here yet.Digital nautical charts and S-57

The U.S. military established something called the vector product format (VPF) to define every sort of data type possible for map display. The digital nautical chart (DNC) is a subset of VPF that NIMA says will eventually replace all paper charts on U.S. Navy and Coast Guard vessels, even be the source of paper charts while they are still needed. NIMA has converted thousands of raster charts into a seamless U.S. DNC and is working on a worldwide database.

NOAA is also developing vector charts. They have chosen to use the S-57 format hammered out over many years by the International Hydrographic Organization (IHO) for use by commercial shipping. (NIMA hopes to get IHO acceptance of the DNC). NOAA has limited its initial goal to about 200 major approach and harbor charts, and the detailing is focused on the needs of large ships.

What’s particularly noteworthy about NOAA’s work is that they have gone beyond raster imagery for certain critical features; for instance, they’ve gone back to Corps of Engineers reports for data on dredged channel limits. In small ways they’ve realized the dream of removing andquot;drawnandquot; data from the charting process. Maptech may issue NOAA’s vector data as part of its Professional Series this year.

Meanwhile, Nautical Technologies is working under a non-exclusive CRADA (Cooperative Research and Development Agreement) to build a government version of the Cap’n charting software that will display the DNC. Cap’n developer Dennis Mills said that DNC detail is amazing: andquot;You can tell if a shore-side church is a mosque or a synagogue, if you want.andquot; Dennis said that, while some vector chart databases can fit whole continents on a single CD, the DNC is so data rich that the coastline from Block Island to Norfolk fills a CD. Mind you, military navigators – NIMA’s prime customer – want detail for everything from submarine warfare to SEAL landings on remote shores.

NIMA plans to offer the U.S. DNC to the public as soon as a USCG-approved updating system is completed. The rest of the worldwide DNC will be released as copyright arrangements are made with foreign HOs. The Pinpoint Group’s SoftChart and Nautical Technologies companies plan to market the charts and display software as soon as NIMA releases the database. Presumably other developers will follow.Other vector charts

At one point the U.S.S.R. also had a military vector-charting project underway, but due to political changes it morphed into an international private sector company called Transas. This company markets its vector chart database (and related systems) directly to big shipping companies and indirectly as Nobeltec’s Passport Charts. These charts displayed with Nobeltec’s Visual Navigator Suite 5 have won the affection of many PC navigators this last year. The company, now a division of Boeing and populated with programmers from 3 different charting companies, has focused almost all its resources on the development of VNS 6, which both makes up for some of the shortcomings of Passport charts and really shows off what vector charts can do.

Some Passport users were disappointed with the paucity of land topography and feature data. VNS 6 more than fixes that problem (at least in the U.S.) by integrating both U.S. topo lines and a detailed street map with Passport’s marine data. Another vector database of bottom contours is combined with the topo lines in a filled andquot;wireframeandquot; 3D display that can be shown from any perspective and andquot;flown aroundandquot; in with cursor keys or joystick. Additionally, VNS 6 users will be able to download and display free weather data superimposed on their vector charts (and subscribe to more detailed forecasts if desired). VNS 6 with Passport charts has been a hit at the fall boat shows.

It’s understandable that Transas skipped land features when building its vector database as the process is so very labor intensive. Even with automated tracing tools, humans have to do a lot of the painstaking work of identifying and layering chart elements and typing in information. C-Map and Navionics are particularly aware of the work required as both companies have built worldwide vector databases without the aid of any HO’s layered data or military subsidies. Both have teams of technicians numbering in the hundreds whose sole mission is expanding, updating, and improving their database. Consider that level of effort along with the difficulty of managing cartridge inventories, and you can understand their relatively high cost.

Given that every vector chart database has been built from scratch with lots of human intervention in a relatively short period, it should be no surprise that they contain errors. Users have complained of mislabeled and misplaced objects, incorrect aid descriptions, and the like. One former NOAA cartographer, perhaps an alarmist, estimates that 5% of all vectorized data is flawed to some degree, and that it will take years to bring that figure below 1%. Of course, paper charts have their errors, too. But in the transformation from paper to vector, perhaps some additional errors have crept into the process. Undoubtably these mistakes will be caught, but the key thing to remember is that no system is perfect and a navigator needs to remain vigilant.

All the manufacturers are working on improved user feedback and chart update systems. Nobeltec will be providing a new folio of Passport charts with VNS 6, and offering quarterly updates thereafter. Navionics (which also produces Garmin G-charts) already has a system in place whereby dealers can produce a current chart cartridge on demand. C-Map has a similar system in the works. Both companies say that they will soon be providing data on memory sticks, which a user can fill or update with a custom chart pack by web or satcom.

In fact, the cartridge manufacturers – who get less press than the newer PC chartmakers while shipping many more charts – are in no way sitting back on their sales volume. Navionics just introduced a new layering technique that strives for clear displays relative to plotter screen size and zoom level. C-Map cartridges can now be used with MaxSea’s PC charting system. Both companies continue to add detail to their charts and expand their proprietary databases of port information, fishing hot spots, etc.

When asked about the possible competition of the highly detailed DNC vector set, a spokesperson for one of the cartridge companies said that they would happily incorporate any available andquot;officialandquot; vector database into their own if it could be used to reduce consumer prices while maintaining or improving product quality.

In terms of low-cost vector charts, both Garmin and Lowrance have introduced new hybrid PC/plotter cartography products. Garmin’s MapSource Waterways and Lights CD contains coastline, navigation aid, and other data for the entire U.S. With included software, a user can create routes on their home or on-board computer, and then upload them, along with chart sections, to some Garmin handhelds or the new fixed model 162. The resulting display is not at all comparable to the other products discussed here, but for less than $100 it makes a nifty adjunct to paper charts or a backup to a laptop ECS system.

All of the vector chart products mentioned above share one last characteristic of note. Due either to the constraints of plotter screens or the demands of the International Hydrographic Organization, all this vector cartography uses symbols for navigation aids and some other features that are different, sometimes very different, from the NOAA symbols familiar to users of U.S. paper and raster charts. Even NIMA’s DNC will use the IHO’s S-52 symbol set as seen on Passport charts. The developers at the Cap’n are planning to provide their DNC users with a switchable alternate NOAA-style symbol set, an option we’d like to see other developers emulate. A wise navigator should study a new chart type’s symbol set to avoid confusion when underway.

In summary, most developers agree that vector charts are the future. Most envision a navigation solution consisting of one large, flat screen displaying a rich vector chart with all other navigation data windowed, layered, or popped up.What about raster charts?

While vector chart technology is in transition, digital raster charts have technically matured. Two main U.S. producers – Maptech and SoftChart – both offer large catalogs of quality charts. The news about rasters – and it’s pretty big news – is a radically improved data-per-dollar ratio.

Maptech has just introduced its Digital ChartKit 2001. This is a multi-CD bundle that includes the 3.0 version of a ChartKit region with relevant photo maps and coastal topomaps.

Also included is Chart Navigator 4.4, which can display all this cartography and data, and has route-making capability. Chart Navigator will not interface with a GPS (an upgrade is available) but can print out a true-scale andquot;chart packandquot; with the route overlaid. Altogether, this $200 bundle would have cost nearly $1,000 at last year’s prices! At press time SoftChart is strategizing its response.

The year 2001 brings yet more choices in electronic charting. For some that means more tools; for others it means more confusion about which way to go. Whichever is your point of view, expect the trend to continue.

By Ocean Navigator