Now if we reduce the time resolution somewhat and accept we may not know at the exact moment where any particular plane is but that it will get captured on a satellite every X minutes you can really start cutting into those numbers.
If they "disapear" it's no great mystery as to where they might be .. they have thoroughly planned to within a metre flight paths and are on contract to drape specific areas.
However, they are loaded with instrumentaton: magnetic sensors, radiometric sensors, EM sensors for EM surveys, multiple GPS receivers and calibrate to neutral for data collection runs (like zero'ing a scale with a empty tub on when cooking to just measure the tub contents and not the tub).
There's an aversion to unshielded equipment, extranuous broadcasts, and pilots wearing glow underwater divers watches with radium dials.
Perhaps others had different practices or flew different instruments such as optical photogrammetry.
If you're seeing gridding at 80m ground clearence perhaps it's crop spraying or perhaps your software is infilling lines from turnpoint position blipping with nothing for the next 50km.
EDIT: I note you submitted this article and have an interest in aerial surveillance programs, I'm simply recounting the practices of one rather busy Australian geophysics company thta was subsumed into Fugro some time past. We considered aircraft and crew safety and had a 20+ year no crash no lives lost record and regularly considered aircraft position signals .. that said we avoided "polluting" the spectrum with broadcasts when aquiring signal and largely relied on off grid checkins (even just three radio blips) ever few completed lines.
I dare say some operators contracted for non EM work (say, radiometric survey) might broadcast during aquisition lines but I find it hard to believe that a good operator would broadcast during EM runs.
Aeromag and radiometrics tend to be low level and tight; 80m ground clearance, 200m line spacing (unless for regional levelling of multiple small infill surveys).
Photogrammatic sureys are higher with much wider spacing, the frames are large and there's really only need for a 50m or less overlap to get a good broad area mosaic.
I'm guessing you have routines to analyse and classify flight activity by path characteristics and coarsely bucket activity?
http://www.astronautix.com/u/us-a.html
It probably wouldn't be feasible to have a single constellation tracking both aircraft and ships. Different types of radar operating on different frequencies would be needed for those applications.