Geospatial PDF in Adobe Acrobat: Examining latitude and longitude values
After creating a map with MAPublisher or Geographic Imager, you might want to export it as a geospatial PDF file. You want to ensure that the georeference information of your Geospatial PDF files are correct before bringing them into the field for use. A great way to use geospatial PDF maps (and GeoTIFFs) is to load them onto an iPhone, iPad, or iPod touch with PDF Maps installed.
One way to check for georeference accuracy of geospatial PDF files is to use Adobe Acrobat. Open the "Analysis" tool from View > Tools > Analyze.
Click the "Geospatial Location Tool" from the Analyze panel.
With the Geospatial Location Tool enabled, you can see the latitude and longitude values of the map while you move the mouse over the opened Geospatial PDF file.
An important tip you should keep in mind: you need to set the preference option for this tool correctly depending on the coordinate system of the map in the geospatial PDF file.
Open the Preference dialog window:
Acrobat X on Windows: Edit > Preferences > General ...
Acrobat X on Mac: Acrobat > Preferences ...
In the Preference dialog window, find the preference category "Measuring (Geo)" from the list of categories.
In the "Measuring (Geo)" category, take a look at the right side. There are many options for the georeferencing tool. One of the options is "Latitude and Longitude Format". In this section, you have a checkbox option "Always display latitude and longitude as WGS 1984".
This option is very important. If the coordinate system of the map is "NAD 27 / UTM Zone 16 N", which geodetic system would you like to have to show the latitude and longitude values in Adobe Acrobat? For example, if you are checking the latitude and longitude values in the WGS 1984 geodetic system, you should keep this option selected. However, if you are checking the latitude and longitude values in NAD 1927 geodetic system, then you should de-select this option. The difference in the distance at the same spot between two different geodetic systems may be small or large. If you would like to see the correct latitude and longitude values, you should be aware of this option.