Eclipse Path - 20 April 2023 Map

Map InfoMap Information

Created By: kirkw3
Last Updated: March 13th, 2023 1:03am
Map Coverage:
North: 5.2985°
West: -180° East: 180°
South: -48.4662°
Country: Australia, Indonesia
Price: Free

Transparent Map PC Version Available Works With Garmin

    This map is a transparent overlay of the path of the hybrid annular-total solar eclipse of April 20, 2023, which will pass across Australia, East Timor, and Indonesia.  It shows closely calculated estimates of the centerline, north boundary, and south boundary of the path of annularity and totality.  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, roads, and landmarks depicted in the ordinary map.

    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.

    This map should ensure that someone reasonably inside the displayed eclipse path in locations where the path is relatively wide should be able to view totality or 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 4.2023.1.9.  Astronomical data used with this version of Occult 4 was updated on January 14, 2023.  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 although not identically.  Specifically, where the central eclipse path touches land in Australia and  Indonesia, Espenak's path is narrower but does lie entirely inside the path calculated by Occult 4.  In the narrow zones where annularity transitions to totality and vice versa, the two calculated paths are separate from each other with no intersection.  (In the southwest transition zone, Occult 4's calculated centerline lies roughly 6-10 km south of  Espenak's.  In the northeast transition zone, Occult 4's calculated centerline lies roughly  2.8-4 km north of Espenak's.)

    To use this map, copy the file "eclipsepath20apr2023.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 that on some devices such as the DriveSmart 65, the eclipse path will not appear on-screen until viewed at high zoom levels (i.e., close up).  An alternative procedure may be necessary to install the map on Nuvi devices.  All users should carefully read the instructions included in the zip file prior to installing the map.

    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 4.2023.1.9.  Ephemeris DE441 and program-estimated deltaT=69.45 were incorporated into the program's computations.  Data was parsed and organized manually and with custom-written software and splitter-r653 and compiled with mkgmap-r4905 on January 21, 2023.  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 March 13, 2023.  The URL links in the text above were valid on March 13, 2023.

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Changes:  March 13, 2023  New map posted to GPSFileDepot.com.


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