Archive for the ‘Cartography’ Category

Coast Survey improves access to data on thousands of wrecks and obstructions   5 comments

Knowing the locations of shipwrecks and other obstructions has always been important for safe navigation ‒ but mariners are not the only people who want to know about wrecks. They are also important for marine archeology, recreational diving, salvage operations, and fishing, among other interests. Now, Coast Survey has improved our Wrecks and Obstructions Database, giving everyone easy access to new records to explore.

Web-based map of wrecks

Coast Survey’s wrecks and obstructions database provides info on thousands of wrecks.

Historically, Coast Survey has maintained two separate sources of information on wrecks. We recently combined the sources, bringing together information on nearly 20,000 wrecks and obstructions.

AWOIS

Coast Survey established the Automated Wreck and Obstruction Information System (AWOIS) database in 1981 to help estimate the level of effort required to investigate items during a planned hydrographic survey, but maritime users were also interested in AWOIS’ historical records. However, because the emphasis is on features that are most likely to pose a hazard to navigation, AWOIS has always had limitations. Most notably, AWOIS is not a comprehensive record and does not completely address every known or reported wreck. Additionally, for a number of reasons, AWOIS positions do not always agree with a charted position for a similar feature.

NOAA ENC

Coast Survey compiles NOAA’s electronic navigational charts (NOAA ENC®) from sources on features that are navigationally significant. As the official chart data used in electronic chart and display information systems (ECDIS), ENCs are the authoritative source of information about known or reported wrecks and are much more comprehensive than AWOIS. However, the features in an ENC typically lack the historic information and context provided by AWOIS.

COMBINED DATA

Correcting for some overlap between the two source databases, Coast Survey’s new wrecks and obstructions database now contains information on about 13,000 wreck features and 6,000 obstructions. Wreck features from each original database are stored in separate layers but can be displayed together. Users may also choose a background map from several options.

The new database also offers users additional data formats from which to choose. Historically, shipwreck data in AWOIS was available in Adobe PDF and as Microsoft Access Database (MDB) format. More recently, KML/KMZ files replaced PDF and MDB formats, making it easier for public users to view AWOIS data, by using freely available software such as Google Maps or Google Earth. Now, in addition to KML/KMZ and Microsoft Excel formats for general users, Coast Survey provides the data in ArcGIS REST services and OGC WMS services, for use in GIS software programs or web-based map mashup sites.

Coast Survey unveils NOAA ENC Online enhancements   1 comment

In November 2013, we introduced NOAA ENC Online – a continuous viewer for our electronic navigational charts. You can click on the web map and zoom to selected features or locations, to see the information contained in over a thousand electronic charts of NOAA-charted waters. Each zoom moves you through an ENC depiction that takes into account the ENC scale and other attributes that are encoded in the ENC, allowing features to become visible or invisible as you seamlessly zoom in and out of the data.

NOAA ENC Online is based on Esri’s Maritime Chart Server.

Now this latest release of NOAA ENC Online lets you:

  • Set a shallow and deep depth contour, which changes the shading to those parameters
  • Set a safety contour (In electronic charting systems, the safety contour is set based on the ship’s draft changes the depiction of rocks, wrecks and obstructions to isolated dangers depending on if the water is “safe” or “unsafe” for vessel navigation.)

ENConline Safety contour

  • Change between S-52 simplified and S-52 traditional symbols

combined

  • Change the background colors of the display based on the S-52 color palette for different light conditions on the bridge of a ship

ENConline color palette

  • Turn off certain features based on different categories such as buoys and traffic routes

ENConline layers switching on and off

NOAA ENC Online is not certified for navigation. It does NOT fulfill chart carriage requirements for regulated commercial vessels under Titles 33 and 46 of the Code of Federal Regulations.

Geographic names disappear from charts, but not from history — #Data4Coasts   Leave a comment

by Meredith Westington, Coast Survey geographer

Good, informed decisions are often based on analyses of historic and present conditions. Researchers, decision-makers, and amateur history buffs find detailed documentation of past conditions in the thousands of Coast Survey charts, dating back to the mid-1800s, in our Historical Map and Chart Collection.

Just like present day nautical charts, historic charts contain a wealth of information about geographic features — including their names, shape, and condition. Geographic names are important locational references for today’s emergency responders, but current and historic names also convey important aspects of local people and culture, which may persist through time.

As Coast Survey’s nautical cartographers routinely apply new topographic and hydrographic data to improve decisions at-sea, a question arises about names when a geographic feature, such as an island, bay, or bayou, has changed: does the associated place name disappear when the geographic feature is no longer there, or does the local population still use the historic name to convey a shared sense of place?

Coast Survey cartographers raised this exact question after applying new shoreline information to charts covering Louisiana. When cartographers applied new shoreline data to charts 11358 and 11364 in 2011, they found that named features were no longer there (see the images below for a comparison of today’s landforms vs. the historic landforms in 1965). In early 2013, another new shoreline survey similarly affected fourteen geographic names on chart 11361. They removed these “dangling names” to reduce chart clutter, but are there new names for the areas where the features used to be?

chart comparisons

On the left is the area south of Buras, Louisiana, on Mississippi River chart 11364, 2012 edition. On the right is the same area shown on Mississippi River chart 1271, 1965 edition.

Losing places (and their names) may mean losing important locational references. Some of these places have appeared on NOAA’s nautical charts of Louisiana since the late 1800s, so their removal raises concerns about a loss of cultural identity on the landscape. For example, Cyprien Bay was named for longtime resident Cyprien Buras. The names live on, of course, on the historic maps and charts in Coast Survey’s Historical Map and Chart Collection. Importantly, they are also retained in the lesser-known U.S. Board on Geographic Names’ federal repository of place names, the Geographic Names Information System. The system’s current and historical records make a great starting point for finding names that you can use to locate relevant historical nautical charts in the Historical Map and Chart Collection. The collection has an easy-to-use geographic place name search function. Just type in a name, and start to explore our nation’s geographic changes…

Search over 35,000 historical maps and charts.

Search over 35,000 historical maps and charts, just using a geographical name.

Great Lakes mariners get new NOAA nautical chart for St. Mary’s River   Leave a comment

Vessel operators transiting St. Mary’s River, between Lake Superior and the lower Great Lakes, have a new nautical chart to help lessen the dangers inherent in this narrow and complicated waterway. The first edition of Chart 14887 (St. Marys River – Vicinity of Neebish Island) is available this week as a paper print-on-demand chart, PDF, and raster navigational chart. The electronic navigational chart will be available by March, in time for the beginning of the shipping season. (UPDATE, 2/12/14: NOAA ENC US5MI50 is now available.)

Coast Survey has built the chart from original sources, providing the highest standard of accuracy for hydrographical and topographical features and aids to navigation. The chart provides large-scale (1:15,000) coverage of the up bound and down bound channels of the St. Mary’s River – one of the busiest waterways in the nation. Over 4,100 transits of commercial and government vessels move about 75 million tons of cargo through the 300-day shipping season.

Corrected shoreline, chart 14883

The red lines show the shoreline as depicted before the updates. NOAA cartographers are applying the corrected shoreline and feature positions to the new chart and new editions of current charts in the Great Lakes.

Chart 14887 uses updated shoreline data, collected with NOAA’s high tech remote sensing planes. (See National Geodetic Survey’s shoreline data viewer.) At the 1:15,000 scale, the positions of many of the features were corrected an average of ten meters from positions in prior charts, a vital correction for precision navigation by vessels that can exceed a thousand feet long.

Coast Survey also plans to issue new editions of the current four largest scale charts of the St. Mary’s River in late January. Charts 14882, 14883, 14884 and 14962 will have all new shoreline, updating the locations of features and aids to navigation. These updates for the St. Mary’s River follow 21 new editions for Great Lakes charts from Buffalo to Thunder Bay Island, around the Lower Peninsula to Milwaukee Harbor and Ludington. More updates are slated for 2014 and 2015.

Chart 14887 was compiled by Nathan Burns and reviewed by Laurie Bennett, under the direction of Marine Chart Division branch chief Andy Kampia.

Iron ore shipment on Lake Superior

Updates to NOAA’s Great Lakes nautical charts will benefit ships like this one, carrying iron ore on Lake Superior. Photo courtesy of Carolyn St. Cyr.

Happy holidays to chartmakers in the U.S. and around the world   2 comments

Holiday card 2013

Coast Survey unveils NOAA ENC Online Viewer

For more than ten years, since NOAA introduced its electronic navigational charts, you have needed to purchase a specialized chart display system to view the NOAA ENC® as a seamless chart database. Starting today, you don’t need a system to view the ENC depictions; you can use Coast Survey’s new web-based viewer called NOAA ENC® Online. (IMMEDIATE CAVEAT: You still need a specialized display system to use the multi-layered functional data that make ENCs so valuable. NOAA ENC downloads are still free to the public.)

Since NOAA ENC Online is web-based, there is nothing to download. Users can click on the web map and zoom to selected features or locations, to see the information contained in over a thousand ENCs of NOAA-charted waters. Each zoom moves you through an ENC depiction that takes into account the ENC scale band and other attributes that are encoded in the ENC, such as scale minimum and feature masking. This allows the user to seamlessly zoom from the high level of detail of the large scale Band 5 ENCs, to small-scale overviews available on Band 1. Viewers can measure areas and distance, and use other functions.

Screengrab from NOAA ENC Online

Screengrab from NOAA ENC Online

In addition to providing public access to chart data, ENC Online will also help NOAA cartographers improve our current suite of ENCs. For instance, this web service allows cartographers to more easily pinpoint areas that may need additional hydrographic surveys for chart updates and corrections.

ENCs are increasingly popular with commercial mariners, who value the charts’ flexibility and multi-layered information. Starting today, we hope other chart users will plumb the depths of ENC Online and discover its many uses as a practical resource.

NOAA ENC Online is not certified for navigation. It does NOT fulfill chart carriage requirements for regulated commercial vessels under Titles 33 and 46 of the Code of Federal Regulations.

The NOAA ENC Online viewer is powered by Esri Maritime Chart Server technology. The technology provides features that can be leveraged in various GIS and OGC WMS compliant applications.

Better nautical chart images coming to electronic charting systems

Things are changing for U.S. nautical charts. We think you’re really going to like this improvement!

The NOAA RNC is a geo-referenced digital image of the traditional paper chart. When it comes to digital graphics, higher resolution is generally better than lower resolution. Dots per inch (dpi) measures the image resolution: the higher the dpi, the better the resolution, the clearer the image. Today, cartographers at Coast Survey are busy improving the resolution of NOAA RNCs, increasing the chart images from the current 254 dpi to 400 dpi. This change improves the clarity, readability, and aesthetics of this highly popular digital charting product.

Coast Survey maintains over a thousand RNCs that are available as free downloads. Our Marine Chart Division is transitioning the entire suite, updating and checking quality on all the charts, and we expect all RNCs to be upgraded to the 400 dpi by January 2014. Don’t worry, we aren’t taking anything offline. You won’t even notice that we’re changing the RNCs, except that you’ll see clearer images after your chart has been changed to 400 dpi.

RNC screengrab at 254 dpi

RNC screengrab at 254 dpi

RNC screengrab at 400 dpi

RNC screengrab at 400 dpi

This improvement in RNC clarity will make it easier and faster for mariners to interpret the information on the chart. Less time puzzling through ragged graphics means more time to increase situational awareness.

We’ve included a 400 dpi test dataset on the NOAA RNC webpage, so RNC users can give it a try. The test dataset includes BSBs for Detroit, Long Island Sound, Puget Sound, and Tampa Bay. We hope that users and developers will let us know if you discover any problems with the test dataset. (Submit comments here.) We’ve listed some frequently asked questions below.

FAQs

Does this change the actual format of the RNC? No. The only change is the resolution of the chart image.

Will higher resolution files have bigger file sizes? The average increase in file size is around 50 percent, but that is easily handled by today’s computers, mobile apps, and display systems.

When will all the high-resolution RNCs be available for public download? If the transition goes as planned, NOAA expects to upgrade all RNCs to 400 dpi by the end of 2013.

I currently use the NOAA RNC suite in my chart plotter. Will the high-resolution RNCs work as well? We expect no compatibility issues in this upgrade. If you do have technical problems with this upgrade, contact your software provider for technical assistance. We encourage software providers to let us know of any difficulties during the testing period. Submit comments and questions to NOAA’s Nautical Inquiry & Comment System.

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