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This package was compiled by the FAA Alaskan Region Public Affairs Office in Anchorage and sent to FAA managers with a memo from Paul Steucke dated March 5, 1987. It gathers material on the November 17, 1986 sighting by the crew of Japan Air Lines flight 1628: a news release, pilot and controller transcripts, crew interviews and radar analysis. The FAA concluded that it could not confirm the event. It attributed the second radar target to a split, uncorrelated return from the JAL Boeing 747 and planned no further investigation.
“Ç.”30 pages
Federal Agencies Digitization Initiative Still Image Working Group - August 2010 - SIGNAL - "' SFR - Spatial Frequency Response - ( ISO 12233, I SO 16067- 1, ISO 16067-2, I SO 15524) c: MTF - Modulation Transfer Function-~~ ·g.~ definition : A spatial frequency descriptor of an imaging system's ability to maintain the relative contrast of input stimuli w Si:!rnl:lliog Bate Resolution Sharneoing A !::l.lti!m;~ ffitre. Q~i;itb Qf~l.l:i Definition: The Definirion: An lm"!llng Defim/Jon :Amplificatio n or the SFR Definit:iotr. An objective Derlflition : o s "rty Defimlicn: Tl>e d/Sfance QI reciprocal of !11e system's aoillty to resol\/e by means of image processi ng to SFR based metric that Is or wide spreading olong tire optical ains 1-nrNn ilCa!ptab/e <hSlance between The 1...,,1 of spatial detail U1at perceiived image frx:us. Closest adjacent can resolved 1n an Image sharpness. pixels. The number or samples per unit distance. • Megapixels - Blurred - Oversharpening ( haloing, garish • Sharp - Low oontrast • Deptl1 ol field ]l •~ • Dots per Inell (dpi) - So~ edges) - Hazy • Cirde ol oonfusion • Pixels per Inch (ppi) - Sharp - Snap - Ghosting • Focus tolerance ~i~ • Samplng frequency - In/Out of locus - Edgy, Sharp, Crisp • Yelling nare • Hyperfocal distance ~ ~ - Spherical aberration - Edge enhancement • Glare "O - Spatial de!illi - Unsharp masking - Integrating cavity effect f!CEl e :The number d e :10% sampling ef'ficiEncy e: Max SFR gain e: Area under 111e SFR •%Rare - e :Distance alOflll the ~ i captured or based on Luminance SFR units: % SFR resPonse as weigh!Ed by an units: (unit less) optical axis that remains de!M!red pixels per units: ( unit less) appropriately chosen In aa:eptable locus ~j unit distance In botl1 visual oontrast function. units: inches, mm. N~~ tl1e horilolltal and • : Min/Max 10% spatial units: TBD vertical dimensions frequency limits of l.IJmlnance 5 ! units: dots - per ~inch , SFR II urits: dot cvdes/ mm ~ ~ o pixels·per-lnch w : Min/Max 50% spatial w : Siiln of SFR slope ~ - "' trequency limits of Luminance units : positilleJ negative Slope rtid:: ~ II SFR vaf!Je • urits: dol, cvcles/mm - Poor canbration • Poor (auto) focus • OVer aggressive sharpening - Op(lcal performance - Dirty lens • Poor F-nll!lber choice ., QJ ~ technique • Poor optics settings exx:eeds sampling rate • Light source ~~ • Wrong choice or • Poor choice of apertUre stop - I nsumoent sig nal to amplify dlrea:ed into lens units at callbratlon - Mechanical vibration - llllnl<ing that If a little Is good • Poor quality lens ~ 42 13 • Oller" aggressive rolse !11en more must be better. - Stray light control Technical Guidelines for Digitizing Cultural Heritage Materia ls: Creation of Raster Image Master Files 10 _J_
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