A user on the forum indicated trouble using multiple DTED levels and asked if the RPFDataSeries duplicate series code in the enumeration may be contributing: https://github.com/NASAWorldWind/WorldWindJava/blob/2d1e121076bbdf2bca9b6d738a63604307617020/src/gov/nasa/worldwind/formats/rpf/RPFDataSeries.java#L98 Forum Post: https://forum.worldwindcentral.com/forum/world-wind-java-forums/development-help/156945-bug-in-rpfdataseries I'm not sure if it is a duplicate series or if it is the reason for the DTED elevation issue.