Eclipse Path - 26 December 2019 Map

Map InfoMap Information

Created By: kirkw3
Last Updated: October 28th, 2019 1:10am
Map Coverage:
North: 26.6645°
West: 47.875° East: 157°
South: 0.230713°
Country: Guam, India, Indonesia, Saudi Arabia
Price: Free

Transparent Map PC Version Available

    This map is a transparent overlay of the path of the annular solar eclipse of December 26, 2019, which will pass across the Arabian Peninsula, southern India, the northern Indian Ocean, Indonesia, southern Singapore, and the northwestern Pacific Ocean.  It shows closely calculated estimates of the centerline, north boundary, and south boundary of the path of annularity, within which the entire disc of the moon will appear as a silhouette in front of the sun.  This overlay is intended to be displayed on Garmin devices on top of a user's ordinary map and will show the eclipse path with respect to the cities, highways, and landmarks depicted in the ordinary map.

    Note that this is an annular and not total solar eclipse.  In no viewing location will the moon cover the sun completely and the solar corona will not be visible to the naked eye.  Proper eye protection MUST be employed when viewing ALL stages of the eclipse, including the times between second and third contact when the disc of the moon will appear entirely inside the bright disc of the sun's photosphere.

    Feel free to use this map and to pass it on to other people, but please read and pass along this disclaimer, too:

    NOTICE:  This eclipse path map is a close approximation but is NOT exact.

    While subject to possible variations of several tens or hundreds of meters, this map should ensure that someone reasonably inside the displayed eclipse path should be able to view annularity.  This map for Garmin devices was compiled based on eclipse boundary points computed at longitude intervals of 7.5 minutes by David Herald's astronomical occultation prediction program Occult 4.9.2.1.  Astronomical data used with this version of Occult 4 was updated on October 20, 2019.  The updated data and closely spaced data points should enhance the accuracy of the map's predictions.  However, it cannot be precise.  This map has been compared and spot checked with data published by NASA/GSFC's Fred Espenak and has been found to track the curves from that data closely and consistently, although not identically.

    Specifically, the eclipse's centerline in this map appears within 40 to 175 meters north or south of the centerline predicted by Espenak.  The difference is greater over the Arabian Peninsula and Arabian Sea, with this map's eclipse centerline appearing as much as 900 meters north of the Espenak prediction.

    Additonally, the zone of annularity of this map is slightly narrower than that predicted by Espenak, although the northern and southern central eclipse boundaries lie entirely inside the boundaries predicted by Espenak.  This may be due to the eclipse elements on which this map is based (L2 in particular) describing a smaller radius for the moon's shadow than that described by the elements used in Espenak's prediction.

    In general, various astronomical sources incorporate slightly different eclipse elements into their calculations, which will result in slight differences in predicted eclipse path boundary lines.  Also be aware that the map's curves were interpolated from a finite collection of fixed points and that rounding or compression errors may occur during the compilation of the map.  More importantly, the curves of this map do not take into account the irregular, mountainous edge of the moon.  These lunar irregularities may shift the eclipse's antumbra on earth by up to 1 to 3 km (0.6 to 1.9 miles) north or south.  All of these factors are significant to viewers situated near the edge of the path.  Those users are advised to consider the north and south limit lines as approximate when viewed at high zoom levels.  Viewers should NOT use the curves of this map to position themselves at the precise edge boundaries of the eclipse path (for example, in order to view enhanced displays of Baily's beads).  This map's accuracy is not sufficient.  Instead, those people wishing to do so should consult an accurate scientific reference just prior to the time of the eclipse.

    Also included as a separate file is a GPX file of the path of the centerline only.  This track file was created from the same Occult 4 data and is subject to the same accuracy limitations.

    To use this map, copy the file "eclipsepath26Dec2019.img" to the "Garmin" folder on the removable SD card in the Garmin GPS device.  It should also be possible to copy the file to the "Garmin" folder in the device's internal memory provided the file does not share the same name as any other existing file.  If you have installed a previous or different version of this map, first delete the old IMG file, as the two maps have the same map ID and cannot coexist.  Exercise caution not to overwrite, move, or delete any other files or folders when installing this map.  When finished, disconnect the GPS device from the computer if applicable.  Then turn on the device normally and go to the start or menu screen.  On many devices, go to the "Setup" menu and select the "Map" and then "Map Information/Select Map" options.  Two or more different maps can be displayed simultaneously on modern devices; on the list of available maps, ensure that "Eclipse Path" and a general map of the area of interest are both enabled.  (This may be done on certain devices by tapping the map name and then choosing "Enable.")  Return to the main menu and view the map.  The eclipse path will be superimposed on the other map.  It may be desirable to zoom outward when first viewing the eclipse map before zooming in to an area of interest.  (The above procedure was tested successfully on an Oregon 200.)

NOTE TO NUVI USERS:  A user reported that he was unable to display an eclipse map of this series on his Nuvi device after following the above instructions.  The author has confirmed this issue on a Nuvi 350 (Software ver 6.10).  It may be possible to display the eclipse map on this and similar Nuvi devices by following an alternative procedure.  Read the text file "Readme_eclipse_path_instructions_26Dec2019.txt" which is included in the zip file that can be downloaded from this web page.  Refer to the Nuvi instructions in that file.  This procedure was successful on the above-mentioned Nuvi 350.  Be aware that the procedure is straightforward but intended for experienced computer users and that users take the risk of potentially disabling their Nuvi device's functionality.  Nuvi users voluntarily follow the steps at their own risk and the author assumes no responsibility for any resulting damages.  See zip file for specific instructions.


    This eclipse path map was created and compiled by GPS File Depot member kirkw3 from data calculated by David Herald's Occult 4 occultation prediction astronomy program, version 4.9.2.1.  Updates including Ephemeris DE438 and program-estimated deltaT=69.52 were incorporated into the program's computations.  Data was parsed and organized with custom-written software and splitter-r580 and compiled with mkgmap-r3676 on October 20, 2019.  While believed to be accurate within the described limitations, the author assumes no responsibility for this map file's use/misuse or any consequential damages.

    This map was posted on GPSFileDepot.com on October 28, 2019.  The URL links in the text above were valid on October 28, 2019.

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Changes:  Oct. 28, 2019  New map posted to GPSFileDepot.com.


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