Version 3 (modified by mark1, 7 years ago) (diff)


Q: Why does my mapped image have black bars across track?

If you see black stripes across your mapped image, as in the shown figure, these are due to missing scans. The Eagle and Hawk instruments occasionally "drop" scans, i.e fail to record the scan, due to instrument component failures or data recording rates. This is most notable in 2009/2010 data where there were issues with the frame grabber card. These stripes are essentially empty data (level 1 file has 0 values there) and are used as 'spacers' for the navigation synchronising.

When mapped with aplmap (current version 2.2.3) the values from the level 1 file (the 0s) are inserted into the map. In a future release the mapper will be updated to accept "ignore values" such that these regions can be interpolated across as requested.

Image showing dropped / missing scan lines

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