Issue with ENC maps incorrect overlap

JillSlater_

We have loaded an ENC (C-Map) into our ArcGIS Server version 10.7.1 with the Maritime Extension installed. We are having an issue where it looks like one of the North American maps overlaps with the European maps, and can't figure out if it is an issue with the way it was loaded, or if it was an issue with the data that was delivered to us.

This is the North Sea below, and the red area that is circled is actually coming from the North American map - we can see it line up when we pan west to North America.

Does anyone understand what might have caused this to happen with our maps - or what we can do to try and resolve it? I was not involved in loading the map and have not used Maritime server extension myself, but I will need to provide our IT team suggestions for how to resolve this.

 

TomDePuyt

Hi Jill,

This, more than likely is being caused by the differences in scales of data in that area.  As you zoom in/out the best available datasets will display based on your display scale and the datasets compilation scale.  You can read more about this calculation here under the “DisplayParameters” section.   I don’t recommend you change your DatasetDisplayRange but that can be something to experiment with.

 

There is also a feature level attribute called SCAMIN that will suppress the drawing of features until they are within the right display scale to view.  By default the service is set to honor that setting.  It is part of the S-57 standard to optimize draw performance.  If turned off, your draw times could be impacted and your display cluttered.

 

The Maritime Chart Service (MCS) capabilities have over 30 display properties that help users customize their view of the data, similar to an ECDIS experience.  If you don’t have our maritime widgets deployed you can download them here to create a web application.  You can also use NOAA’s public service as well  https://nauticalcharts.noaa.gov/enconline/enconline.html. Please note, that NOAA’s service is running an earlier version of MCS and the widgets but the examples I’ve attached still apply to your version.

 

In Example1.png, you will see the default view of the data as published by NOAA.  Their default settings might differ from yours.

 

In Example2.png, I have modified some of the display parameters using our display properties widget.    You can read more about the numerous display properties and how to configure them on your service here.   As you can see by NOAA’s example you have 3 different scales of data in the same area.  There is a General, Coastal and Approach data.  The Coastal data is being drawn but most features as you will see in Example3.png are being suppressed by the SCAMIN attribute.  You can either zoom in to view the data at scale or turn off the SCAMIN attribute.

 

In Example3.png, I turned off the SCAMIN property so data not at scale is now being drawn.  This also identifies another set of settings that you might want to change.  Note how the soundings from the Coastal data are smaller than the soundings from the General data.  That is because we do not set the display of text and symbols to a 1:1 ratio.  This default is changing at 10.9 but for your version you can alter those values (if desired) in the S52DisplayProperties.xml.  This is part of the DisplayParameters section that I mentioned above.   You need to set the minZoom and maxZoom for the following to 1.

• AreaSymbolSize
• LineSymbolSize
• PointSymbolSize
• TextSize

 

By changing those values and restarting your map service, features and text will display at the same scale regardless of the differences in complication scale for those datasets.  This is more of a traditional ECDIS view vs. a GIS view.

 

If you feel that data is truly missing from the service, then you can check the log files under your MCS deployment to see if that dataset did not load.  That could be due to the data supplier not providing you the proper permit.txt file to access the data but it appears it just has to do with differences in compilation scales between countries.  This is very common.

 

If you would like to know more about our configuration settings, just let me know and we can setup a meeting to discuss in more depth.

 

Thanks,

Tom

 

 

 

 

 

Example1.png

Example2.png

Example3.png