DETECTION of LAND AREA OBJECTS (applies to S-57 ENC charts)
Some of you may have seen a note about this in Notice to Mariners or somewhere else. Apparently some ECDIS systems fail to detect navigational hazards as expected to trigger an alarm. We received a letter from the IHB on this subject. We replied to the letter that NavPak is not affected by this since it does not automatically detect navigational hazards. Both letters are shown below in part to explain the situation.
Letter to Global Navigation Software Company from IHB (in part):
Dear ECDIS Software Manufacturer or User, We are contacting you because you are an IHO S-63 Licensee, and thereby recognised by the IHO as a potential producer or user of ECDIS processing software. The Directing Committee of the IHO has been informed that some ECDIS equipment may not trigger the required alarms and indications based on the detection of the ENC chart object LNDARE (Land Area). As a result, IHO Circular Letter 54/2010 – Limitations in ECDIS Equipment Software (copy at Annex A) was sent to all IHO Member States and Accredited Observers. The problem described in IHO Circular Letter 54/2010 appears to be associated with ECDIS software rather than ENC data encoding......" End excerpt of letter from IHB. The letter continues with a questionnaire about our software which we completed, and we also sent the following reply (in part):
Dear IHB, Thank you for keeping us informed. NavPak does not automatically detect objects that are navigational hazards. We left this as an exercise for the navigator. We chose not to implement this feature because it is very resource intensive and may not work in some circumstances. LNDARE objects would be one of the most resource intensive objects to check since they are so big and numerous. Maybe this is why we hear about ECDIS systems crashing every now and then. After browsing through thousands of ENC charts from various sources, I have seen inconsistencies in how some attributes are encoded for objects that may be navigational hazards. For example I have seen rocks, wrecks, and obstructions where the depth is encoded as part of INFORM instead of VALSOU. In this case the system may fail to detect it or it may trigger a false alarm. I mention this only to illustrate why we did not implement a function to detect navigational hazards ahead.
If you have any questions about NavPak or MapSetup, we will be happy to help. Regards, Pete Palmer Global Navigation Software Company
End letter to IHB
/////////////////////////////////////////// NEW NavPak SENC FORMAT
We have been updating the NavPak SENC format since January 2010. The format has not changed since we implemented it in NavPak about 10 years ago. This update incorporates all the improvements we decided to add since then, and should allow for future expansion, so that the format is not likely to change again. All copies of NavPak & MapSetup since June 23, 2010 are using the new format. These early releases of the new format did not utilize all the new features of the format so we did not make an announcement of update at that time. Now the new features are enabled and fairly well tested, so we are making the official release today (Nov 17, 2010). Since there are major differences from the old format to the new one, it was not practical to make it backward compatible. This means that if you have SENC charts made with old copies of MapSetup (dated before June 23, 2010), then you will need to reconvert the original S-57 ENC files with the new copy of MapSetup to be able to use them with the new NavPak (Pro & Pocket editions). We tried to anticipate future expansion of charting in general so that hopefully it will not be necessary to reconvert your S-57 files again, except when you have chart updates. The new SENC format looks similar to the old format and the conversion from ENC to SENC in MapSetup is similar but a little easier. One thing you will notice is that there are more notes and attributes associated with various objects. Another thing is that there are provisions for a polygon of detail in the chart file. Previously SENC charts were all rectangles, now you can define a polygon boundary of up to 48 sides. The new MapSetup has a function to digitize the polygon boundary. Also there are more new tools in MapSetup to work with S-57 ENC and NavPak SENC charts. These include utilities to move and copy files, zoom in while showing cells relative, easier selection of individual cells, and utilities to crop and disassemble cells that have multiple detail areas. We are committed to making NavPak backward compatibile with things like charts, way points and tracks. but in the case of the new SENC format, it just couldn't be done.
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Chart Lock-- (Applicable to NavPak-Pro Nov 15, 2010)
This new feature does more to change the look and feel of NavPak since adding the NavPak SENC format about 10 years ago. When Chart Lock is on, NavPak behaves exactly the same as older copies. When Chart Lock is off and a Chart Library is loaded, then when you scroll or zoom to the extent of the existing chart, the next one will be displayed. This is good for quick browsing of charts. If you are drawing or plotting, it is better if the chart does not suddenly and unexpectedly change to a different chart, so this is one of the situations where Chart Lock can be turned on. If Chart Lock is off and there is no Chart Library, then the system will behave the same as if Chart Lock is on. In other words, if Chart Lock is off and you scroll to the edge of the chart or zoom all the way in or out, then normally the system will display the next chart based on the selection of charts in the Chart Library. If there is no Chart Library, then zooming and scrolling will stop at the extents of the existing chart, the same as if Chart Lock is on. When Chart Lock is on, you can still change charts by all other methods, except zooming and scrolling. These methods include selecting Open Chart in the menu. If a Chart Library is loaded, then you can also change charts using the F5, F6, and F7 keys, and the GoTo buttons in the Way Point, Track, AIS, ARPA and DSC dialog boxes. The system will also change charts if AutoScroll is on, and the GPS position moves off the existing chart, whether Chart Lock is on or off. Chart Lock is turned on and off using the check box in the System Configuration dialog box.
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SATELLITE PHOTOS in C-Map
C-Map has sent us new files to integrate into NavPak Pro to incorporate their latest format which includes satellite photos. We have finished integrating the new C-Map library and DLL, so satellite photos in C-Map will be available soon.
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SATELLITE PHOTOS FROM OTHER SOURCES
There are some interesting third party utilities that you can use to capture satellite photos from the major online satellite photo providers, such as Google. After a little processing with MapSetup and an image editor such as PaintShop Pro, these can be useful for navigation. NavPak will load and scroll a 256 color TIFF chart very fast, even one that is hundreds of megabytes in size, so you should be able to capture a large area at high resolution with one of these utilities and use it to make a photo chart.
As always, don't rely on a single aid to navigation, rather use everything available. On this theme, our favorite way to make a Chart Library is to mix raster, vector, and photo charts in the same library, then you can quickly see all of them by pumping the F6 and F7 keys.
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TECH TIP: Windows turns off power to USB devices as part of its Power Management functions. It is common these days for the GPS to be powered completely by the USB port, so the GPS will stop when the computer goes into sleep and/or maybe hibernate mode. You can prevent this in Windows Device Manager. To do this, go to Device Manager, highlight the USB connection where the GPS is connected then uncheck the box that says: Allow the computer to turn off power to this device. Then click OK to apply it and exit.
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Free almanac for Celestial navigators
http://www.navsoft.com/downloads
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CHARTS
As always we are way behind on updating our list of available charts. If you need charts of a particular area, just let us know by phone or email and we can let you know the latest info. We will generally give everything we have to NavPak users for just a nominal copy and mailing fee. We don't update these but the price is right. This service is reserved for registered NavPak users only. If anyone wants updated charts, C-Map has worldwide charts that are compatible with NavPak. //////////////////////// End NewsLetter.
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