{"baseline":"analysis/nist-panel-crosscheck/baseline/exterior_panels.json","baselineSha256":"28e51ab710187e7fed2512a1d82abf1e31adb1ab3bad6824430317f8a31156c3","sources":[{"tower":1,"source":{"report":"NIST NCSTAR1-5A","printedPage":65,"pdfPage":161,"figure":"6-6","url":"https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=101356","image":"analysis/nist-panel-crosscheck/wtc1/NIST1-5A_Fig6-6_native.jpg","nativeSizePx":[2403,2269],"independentRepeat":{"report":"NCSTAR1-2","printedPage":181,"pdfPage":295,"figure":"7-5(a)","url":"https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=101012"}},"calibration":{"columnPixelAnchors":[[154,495.5],[145,806],[130,1323.5],[115,1840],[106,2150]],"floorPixelAnchors":[[100,882.5],[99,1007],[98,1131],[97,1255],[96,1379],[95,1503.5],[94,1627.5]],"pixelXFromColumn":[-34.46816479400743,5803.861423220965],"pixelYFromFloor":[-124.14285714285776,13296.928571428629],"worldXFromColumn":"(column - 130) * 40/12","maximumColumnAnchorResidualPx":0.5000000000009095,"maximumFloorAnchorResidualPx":0.21428571428987198,"note":"Floor registration uses the labeled slab guide lines, not a spandrel edge. Column registration uses visible intact stem midlines. Endpoint precision is limited by schematic line thickness and source interpretation; +/-0.03story is a display sensitivity range, not a statistical survey error."},"scope":"Only two consequential observed-contour differences are proposed. Preserve FEMA baseline separately and label the rendered panel contours as mixed FEMA/NIST with panel-specific provenance. Do not convert black cladding marks or colored simulation comparison symbols into steel deletions. No new M2/M27/M30 or 3D assumptions.","sourceProbes":[{"column":116,"floor":98.2,"nativePixel":[1806,1106],"coloredPixelsIn21By3Window":0,"coloredOutlinePresent":false,"femaCenterlineRetained":true},{"column":116,"floor":98.3,"nativePixel":[1806,1094],"coloredPixelsIn21By3Window":0,"coloredOutlinePresent":false,"femaCenterlineRetained":true},{"column":116,"floor":97.95,"nativePixel":[1806,1137],"coloredPixelsIn21By3Window":24,"coloredOutlinePresent":true,"femaCenterlineRetained":true},{"column":116,"floor":98.5,"nativePixel":[1806,1069],"coloredPixelsIn21By3Window":30,"coloredOutlinePresent":true,"femaCenterlineRetained":true},{"column":117,"floor":97.3,"nativePixel":[1771,1218],"coloredPixelsIn21By3Window":30,"coloredOutlinePresent":true,"femaCenterlineRetained":false},{"column":117,"floor":97.45,"nativePixel":[1771,1199],"coloredPixelsIn21By3Window":0,"coloredOutlinePresent":false,"femaCenterlineRetained":false},{"column":117,"floor":97.1,"nativePixel":[1771,1243],"coloredPixelsIn21By3Window":63,"coloredOutlinePresent":true,"femaCenterlineRetained":true},{"column":115,"floor":98.2,"nativePixel":[1840,1106],"coloredPixelsIn21By3Window":0,"coloredOutlinePresent":false,"femaCenterlineRetained":false},{"column":111,"floor":98.2,"nativePixel":[1978,1106],"coloredPixelsIn21By3Window":27,"coloredOutlinePresent":true,"femaCenterlineRetained":true}],"inputHashes":{"site/data/exterior_panels.json":"28e51ab710187e7fed2512a1d82abf1e31adb1ab3bad6824430317f8a31156c3","analysis/nist-panel-crosscheck/wtc1/NIST1-5A_Fig6-6_native.jpg":"bf1b84fbb28d4eb2ab20557aedf455631bf2bc4f06cb62e5062510d7527fb741","sources/NCSTAR1-2.pdf":"27e0c4e7ac8950ff8e7884d9aab80cc568ab816912d50961fc382da295fd7a55","sources/NCSTAR1-5A_final_ch1-8.pdf":"fa72da7d03379d22696c3a4153ea91264f4fb816c15af2b9b1d0fa4124ec10aa"}},{"tower":2,"source":{"report":"NIST NCSTAR1-5A final, chapters1-8","figure":"7-25","printedPage":111,"pdfPage":207,"url":"https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=101356","nativeImage":"NIST1-5A-south-pdf207-native0.jpeg","nativeSizePixels":[2403,2255],"pdfImageXref":736,"comparison":"Same observed damage schematic shown in NCSTAR1-2 Executive Summary FigE-46(a), pxciv/PDF96. FigE-46(b) is calculated and is not used for these operations."},"registration":{"columns":[{"column":457,"nativePixelX":392.5},{"column":454,"nativePixelX":496},{"column":451,"nativePixelX":599.5},{"column":448,"nativePixelX":702.5},{"column":445,"nativePixelX":806.5},{"column":442,"nativePixelX":909.5},{"column":439,"nativePixelX":1013},{"column":436,"nativePixelX":1116.5},{"column":433,"nativePixelX":1219.5},{"column":430,"nativePixelX":1323},{"column":427,"nativePixelX":1426.5},{"column":424,"nativePixelX":1529.5},{"column":421,"nativePixelX":1633.5},{"column":418,"nativePixelX":1736.5},{"column":415,"nativePixelX":1840},{"column":412,"nativePixelX":1943.5},{"column":409,"nativePixelX":2046.5},{"column":406,"nativePixelX":2150},{"column":403,"nativePixelX":2253.5}],"floors":[{"floor":89,"nativePixelY":284},{"floor":88,"nativePixelY":408},{"floor":87,"nativePixelY":532},{"floor":86,"nativePixelY":656},{"floor":85,"nativePixelY":780.5},{"floor":84,"nativePixelY":904.5},{"floor":83,"nativePixelY":1028.5},{"floor":82,"nativePixelY":1152.5},{"floor":81,"nativePixelY":1276.5},{"floor":80,"nativePixelY":1400.5},{"floor":79,"nativePixelY":1524.5},{"floor":78,"nativePixelY":1669.5},{"floor":77,"nativePixelY":1793.5},{"floor":76,"nativePixelY":1926.5},{"floor":75,"nativePixelY":2059.5}],"method":"Centers of printed dashed grid lines; piecewise floor interpolation preserves the visibly unequal floor spacings. Column interpolation follows labelled three-column centers.","source":"NCSTAR1-5A Fig7-25 p111 / PDF207 original embedded JPEG,2403x2255","axes":"Source right is east (+model x), column numbers decrease rightwards. Model x=(430-column)*10/3 feet."},"rasterUncertainty":{"boundaryCenterPixels":2,"approximatelyFeet":0.2,"approximatelyFloorFraction":0.02,"note":"Manual simplified boundaries follow the centers of visible colored outline strokes. Raster stroke width is not steel thickness; white stem/spandrel interiors are filled as retained faces. Small corner curvature and the short green stub remain approximate."},"scope":"Three complete reviewed retained-face outlines, plus five bounded local panel amendments. Preserve original panel IDs, nominal splice spans and the archived FEMA trace. The remainder of the facade keeps its existing source; gray is display-only uncertainty. Result remains mixed-source, not a completed full NIST transcription.","heldUnresolved":["C411\u2013413 is amended only in its clear left portion. The gray smoke mask and remaining right-side FEMA geometry are not classified from absent outlines. Gray is not inferred removed or intact.","C423\u2013425 upper F80.4\u201383.4 retains its enclosed floor82 spandrel plate. Internal column outline strokes ending within the white plate do not create a void. Remaining local corner/edge differences are approximately a few native pixels, near registration and schematic-stroke precision.","The black dotted wing/tail lines identify marks on aluminum cladding, not severed steel; they produce no clipping operation."],"uncertainRegions":[{"id":"WTC2-S-NIST7-25-smoke-obscured","category":"insufficient_information","boundsOnly":true,"nativePixelBounds":[1954,728,2208,1098],"xFtBounds":[61.019417,85.603865],"floorBounds":[82.439516,85.421687],"columnBounds":[404.318841,411.694175],"columns":[405,406,407,408,409,410,411,412],"levels":[82,83,84,85],"source":{"report":"NIST NCSTAR1-5A final, chapters1-8","figure":"7-25","printedPage":111,"pdfPage":207,"url":"https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=101356","nativeImage":"NIST1-5A-south-pdf207-native0.jpeg","nativeSizePixels":[2403,2255],"pdfImageXref":736,"comparison":"Same observed damage schematic shown in NCSTAR1-2 Executive Summary FigE-46(a), pxciv/PDF96. FigE-46(b) is calculated and is not used for these operations."},"geometryEffect":"none","note":"Conservative display-only bounds around the gray smoke mask. The actual mask is curved/diagonal and does not occupy the full box. These bounds intentionally include a small pixel margin; they do not classify steel as retained or removed and produce no geometry Boolean operation."}],"sourceProbes":[{"label":"C414 upper opening","column":414,"floor":83,"expectedRetained":false,"sourcePixel":[1874.5,1028.5],"xFt":53.333333333333336,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C415 upper opening","column":415,"floor":82,"expectedRetained":false,"sourcePixel":[1840.0,1152.5],"xFt":50.0,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C416 missing continuation","column":416,"floor":81,"expectedRetained":false,"sourcePixel":[1805.5,1276.5],"xFt":46.666666666666664,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C414 lower retained stem","column":414,"floor":81.25,"expectedRetained":true,"sourcePixel":[1874.5,1245.5],"xFt":53.333333333333336,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C415 lower retained stem","column":415,"floor":81.25,"expectedRetained":true,"sourcePixel":[1840.0,1245.5],"xFt":50.0,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C414/C415 retained spandrel","column":414.5,"floor":80.9,"expectedRetained":true,"sourcePixel":[1857.25,1288.8999999999992],"xFt":51.666666666666664,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C417 upper opening","column":417,"floor":80.5,"expectedRetained":false,"sourcePixel":[1771.0,1338.5],"xFt":43.333333333333336,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C418 upper opening","column":418,"floor":81,"expectedRetained":false,"sourcePixel":[1736.5,1276.5],"xFt":40.0,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C419 upper opening","column":419,"floor":82,"expectedRetained":false,"sourcePixel":[1702.1666666666667,1152.5],"xFt":36.666666666666664,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C433 reduced fracture top","column":433,"floor":78.8,"expectedRetained":false,"sourcePixel":[1219.5,1553.5000000000005],"xFt":-10.0,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C434 reduced fracture top","column":434,"floor":78.5,"expectedRetained":false,"sourcePixel":[1185.1666666666667,1597.0],"xFt":-13.333333333333334,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C432 taller retained stem","column":432,"floor":78.7,"expectedRetained":true,"sourcePixel":[1254.0,1567.9999999999995],"xFt":-6.666666666666667,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C433 short retained stem","column":433,"floor":78.105,"expectedRetained":true,"sourcePixel":[1219.5,1654.2749999999994],"xFt":-10.0,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C434 short retained stem","column":434,"floor":78.125,"expectedRetained":true,"sourcePixel":[1185.1666666666667,1651.375],"xFt":-13.333333333333334,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"C433/C434 retained spandrel","column":433.5,"floor":78.03,"expectedRetained":true,"sourcePixel":[1202.3333333333333,1665.1499999999999],"xFt":-11.666666666666666,"evidence":"Manual visible steel-face/opening witness in unshaded source; dotted cladding lines ignored."},{"label":"Bent C417 retained stem","column":417.0000001,"floor":79.842742,"xFt":43.333333,"expectedRetained":true,"sourcePixel":[1771,1420],"evidence":"Interior of the retained green face, not the white gap beside it."},{"label":"Connected diagonal remnant","column":417.5507245,"floor":79.584677,"xFt":41.497585,"expectedRetained":true,"sourcePixel":[1752,1452],"evidence":"Interior of the retained green face, not the white gap beside it."},{"label":"White notch between bent stem and diagonal remnant","column":417.463768,"floor":79.520161,"xFt":41.78744,"expectedRetained":false,"sourcePixel":[1755,1460],"evidence":"Independently reviewed true white opening between members, not the white interior of an outlined steel face."},{"label":"Open window between C414/C415 lower stems","column":414.5072464,"floor":80.568548,"xFt":51.642512,"expectedRetained":false,"sourcePixel":[1857,1330],"evidence":"Independently reviewed true white opening between members, not the white interior of an outlined steel face."},{"label":"C413 upper retained hanging stub","column":413,"floor":83.3,"xFt":56.666666666666664,"sourcePixel":[1909.0,991.3000000000004],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C413 clear gap below upper stub","column":413,"floor":83.0,"xFt":56.666666666666664,"sourcePixel":[1909.0,1028.5],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C413 clear lower opening","column":413,"floor":82.5,"xFt":56.666666666666664,"sourcePixel":[1909.0,1090.5],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C413 absent lower stem","column":413,"floor":81.6,"xFt":56.666666666666664,"sourcePixel":[1909.0,1202.1000000000008],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C412 upper retained hanging stub","column":412,"floor":83.35,"xFt":60.0,"sourcePixel":[1943.5,985.1000000000007],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C412 gap above lower retained stem","column":412,"floor":82.85,"xFt":60.0,"sourcePixel":[1943.5,1047.1000000000008],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C412 continuous lower retained stem","column":412,"floor":82.45,"xFt":60.0,"sourcePixel":[1943.5,1096.6999999999996],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C412 bottom retained stem","column":412,"floor":81.6,"xFt":60.0,"sourcePixel":[1943.5,1202.1000000000008],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C423 shortened upper fracture opening","column":423,"floor":79.5,"xFt":23.333333333333332,"sourcePixel":[1564.1666666666667,1462.5],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C423 lower retained short stem","column":423,"floor":79.16,"xFt":23.333333333333332,"sourcePixel":[1564.1666666666667,1504.6600000000003],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C425 opening above revised fracture edge","column":425,"floor":79.0,"xFt":16.666666666666668,"sourcePixel":[1495.1666666666667,1524.5],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C425 lower retained fracture plate","column":425,"floor":78.8,"xFt":16.666666666666668,"sourcePixel":[1495.1666666666667,1553.5000000000005],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C429 absent isolated remnant","column":429,"floor":78.5,"xFt":3.3333333333333335,"sourcePixel":[1357.5,1597.0],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C430 absent isolated remnant","column":430,"floor":78.5,"xFt":0.0,"sourcePixel":[1323.0,1597.0],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C431 absent isolated remnant","column":431,"floor":78.5,"xFt":-3.3333333333333335,"sourcePixel":[1288.5,1597.0],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C429 separate lower retained green stem","column":429,"floor":78.3,"xFt":3.3333333333333335,"sourcePixel":[1357.5,1626.0000000000005],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C430 separate lower retained green stem","column":430,"floor":78.3,"xFt":0.0,"sourcePixel":[1323.0,1626.0000000000005],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C431 separate lower retained green stem","column":431,"floor":78.3,"xFt":-3.3333333333333335,"sourcePixel":[1288.5,1626.0000000000005],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C431 preserved upper hanging stem","column":431,"floor":79.5,"xFt":-3.3333333333333335,"sourcePixel":[1288.5,1462.5],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C426 removed high fracture mass","column":426,"floor":79.05,"xFt":13.333333333333334,"sourcePixel":[1460.8333333333333,1518.3000000000004],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C426 short retained fracture face","column":426,"floor":78.8,"xFt":13.333333333333334,"sourcePixel":[1460.8333333333333,1553.5000000000005],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C427 removed protruding tip","column":427,"floor":78.76,"xFt":10.0,"sourcePixel":[1426.5,1559.2999999999993],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C427 preserved lower stem","column":427,"floor":78.6,"xFt":10.0,"sourcePixel":[1426.5,1582.500000000001],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C435 observed narrow gap","column":435,"floor":78.36,"xFt":-16.666666666666668,"sourcePixel":[1150.8333333333333,1617.3000000000002],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C436 observed narrow gap","column":436,"floor":78.31,"xFt":-20.0,"sourcePixel":[1116.5,1624.5499999999997],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C435 upper retained end","column":435,"floor":78.5,"xFt":-16.666666666666668,"sourcePixel":[1150.8333333333333,1597.0],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C436 upper retained end","column":436,"floor":78.5,"xFt":-20.0,"sourcePixel":[1116.5,1597.0],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C435 lower retained end","column":435,"floor":78.2,"xFt":-16.666666666666668,"sourcePixel":[1150.8333333333333,1640.4999999999995],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C436 lower retained end","column":436,"floor":78.2,"xFt":-20.0,"sourcePixel":[1116.5,1640.4999999999995],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C437 unchanged retained stem","column":437,"floor":78.45,"xFt":-23.333333333333332,"sourcePixel":[1082.0,1604.2499999999995],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manual witness in unshaded NIST source, away from the colored outline boundary."},{"label":"C412 adjacent retained floor82 plate","column":411.7524271,"floor":81.858871,"xFt":60.825243,"sourcePixel":[1952,1170],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manually registered unshaded source face/opening witness; white steel-face interior remains filled."},{"label":"Revised sloping floor79 retained plate","column":424.5097087,"floor":78.844828,"xFt":18.300971,"sourcePixel":[1512,1547],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manually registered unshaded source face/opening witness; white steel-face interior remains filled."},{"label":"Clear opening above sloping floor79 plate","column":424.5097087,"floor":79.012097,"xFt":18.300971,"sourcePixel":[1512,1523],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manually registered unshaded source face/opening witness; white steel-face interior remains filled."},{"label":"C424 short retained fracture stem","column":424.0145632,"floor":79.076613,"xFt":19.951456,"sourcePixel":[1529,1515],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manually registered unshaded source face/opening witness; white steel-face interior remains filled."},{"label":"C428 left-displaced retained upper face","column":428.3188405,"floor":79.020161,"xFt":5.603865,"sourcePixel":[1381,1522],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manually registered unshaded source face/opening witness; white steel-face interior remains filled."},{"label":"Opening beside displaced C428 top","column":427.9420291,"floor":79.020161,"xFt":6.859903,"sourcePixel":[1394,1522],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manually registered unshaded source face/opening witness; white steel-face interior remains filled."},{"label":"C428 curved retained plate face","column":427.6231885,"floor":78.713793,"xFt":7.922705,"sourcePixel":[1405,1566],"expectedRetained":true,"additionalBoundedReview":true,"evidence":"Manually registered unshaded source face/opening witness; white steel-face interior remains filled."},{"label":"True opening between purple fragments","column":426.4902913,"floor":78.789655,"xFt":11.699029,"sourcePixel":[1444,1555],"expectedRetained":false,"additionalBoundedReview":true,"evidence":"Manually registered unshaded source face/opening witness; white steel-face interior remains filled."}],"spandrelBandOverrides":[{"targetPanelId":"WTC2-S-C423-425-F77.4-80.4","floor":79,"floor_bounds":[78.7,79.092742],"nativeYBounds":[1513,1568],"geometryEffect":"Depth classification only; intersect the authoritative retained polygon. No footprint changes.","method":"Nominal floor79 spandrel upper/lower outline levels visible at the intact right margin and lower horizontal border. The sloped broken upper edge removes only the footprint above itself; it does not erase retained spandrel below that edge."},{"targetPanelId":"WTC2-S-C426-428-F76.4-79.4","floor":79,"floor_bounds":[78.67931,79.092742],"nativeYBounds":[1513,1571],"geometryEffect":"Depth classification only; intersect the authoritative retained polygon. No footprint changes.","method":"Nominal floor79 spandrel depth band, registered against adjacent plate top and the source lower border. Retained left curved face and right square fragment stay disconnected. Internal column/plate junctions and out-of-plane fold depths are not measured by this elevation."}]}],"panels":[{"id":"WTC1-N-C114-116-F95.4-98.4","beforeArea":16.610362941000037,"baselineRegionsSha256":"e3ce8de30a73a11d0bd3527eef56bcc95d615140c51f525df52eb392a261dcec","operations":[{"id":"WTC1-NIST-C116-upper-F98-gap","targetPanelId":"WTC1-N-C114-116-F95.4-98.4","column":116,"operation":"difference","polygon":[[-47.3397,98.1],[-46.11449,98.1],[-46.11449,98.42],[-47.3397,98.42]],"sourcePixelEvidence":{"axisX":1806,"clearGapRows":[1084,1117],"lowerCapOrBandRows":[1118,1122],"upperRetainedEndRows":[1080,1083]},"geometryPolicy":"Cut only the listed FEMA panel's narrow C116 stem above F98. Horizontal padding0.01ft covers its exact original edges. Upper bound98.42 exceeds that panel's98.40726 top by0.01274story solely to finish the Boolean cut. Never cut the next upper panel or the F98 spandrel.","displayGapFloorBounds":[98.1,98.4],"floorEndpointUncertainty":0.03,"historicalInterpretation":"NIST's later observed schematic includes an upper-stem gap absent from FEMA's trace. This is a schematic 2D contour correction, not a new measured 3D fracture."}],"afterArea":16.240050116400038},{"id":"WTC1-N-C117-119-F94.4-97.4","beforeArea":16.11099875385006,"baselineRegionsSha256":"a81dd179c1ae39ef80317e572bc8208c50d34b806db8efbefd9d5d009a5e54e1","operations":[{"id":"WTC1-NIST-C117-retained-tip","targetPanelId":"WTC1-N-C117-119-F94.4-97.4","column":117,"operation":"union","polygon":[[-43.82885,97.18],[-42.68057,97.18],[-42.68057,97.4],[-43.82885,97.4]],"sourcePixelEvidence":{"axisX":1772,"lowerRetainedTipCapRows":[1204,1208],"clearGapAboveRows":[1169,1203]},"geometryPolicy":"Continue only the listed panel's C117 stem at its exact existing width. The polygon starts within the current tip to form a connected union; preserve the upper gap and adjacent C118/C119. Original cap reaches97.19913; new97.40 cap extends it approximately2.41ft.","displayTipFloor":97.4,"floorEndpointUncertainty":0.03,"historicalInterpretation":"NIST's later observed schematic retains a higher lower fragment than FEMA at the upper-west entry boundary. Width is preserved from FEMA; no unmeasured depth offset is assigned."}],"afterArea":16.34165375745007},{"id":"WTC2-S-C414-416-F80.4-83.4","beforeArea":10.833855062999994,"baselineRegionsSha256":"138952f1325fc058dda6767ab60ecfcc5564741724edaa9d8089fc73826044fd","operations":[{"id":"WTC2-S-C414-416-F80.4-83.4-NIST7-25-intersection","targetPanelId":"WTC2-S-C414-416-F80.4-83.4","operation":"intersection","polygon":[[49.42029,81.407258],[50.57971,81.407258],[50.57971,81.084677],[52.705314,81.084677],[52.705314,81.407258],[53.864734,81.407258],[53.864734,81.084677],[54.637681,81.084677],[54.637681,80.729839],[53.864734,80.729839],[53.864734,80.431452],[52.705314,80.431452],[52.705314,80.729839],[50.57971,80.729839],[50.57971,80.431452],[49.42029,80.431452],[49.42029,80.729839],[48.357488,80.729839],[48.357488,81.084677],[49.42029,81.084677]],"sourceBoundaryPixels":[[1834,1226],[1846,1226],[1846,1266],[1868,1266],[1868,1226],[1880,1226],[1880,1266],[1888,1266],[1888,1310],[1880,1310],[1880,1347],[1868,1347],[1868,1310],[1846,1310],[1846,1347],[1834,1347],[1834,1310],[1823,1310],[1823,1266],[1834,1266]],"historicalInterpretation":"NIST shows only the lower C414/C415 stems and one connecting spandrel fragment. The upper FEMA piece and the C416 continuation lie in the unshaded NIST opening. The white interiors of the two outlined stems and spandrel are retained plate faces, not window holes.","priorSource":"FEMA403 Fig2-27 p2-30","retainedHoles":[],"sourceColorPolicy":"Preserve existing panel grouping color; color is not a damage class. This operation replaces geometry provenance with the stated NIST observed source."},{"id":"WTC2-S-C414-416-F80.4-83.4-NIST7-25-union","targetPanelId":"WTC2-S-C414-416-F80.4-83.4","operation":"union","polygon":[[49.42029,81.407258],[50.57971,81.407258],[50.57971,81.084677],[52.705314,81.084677],[52.705314,81.407258],[53.864734,81.407258],[53.864734,81.084677],[54.637681,81.084677],[54.637681,80.729839],[53.864734,80.729839],[53.864734,80.431452],[52.705314,80.431452],[52.705314,80.729839],[50.57971,80.729839],[50.57971,80.431452],[49.42029,80.431452],[49.42029,80.729839],[48.357488,80.729839],[48.357488,81.084677],[49.42029,81.084677]],"sourceBoundaryPixels":[[1834,1226],[1846,1226],[1846,1266],[1868,1266],[1868,1226],[1880,1226],[1880,1266],[1888,1266],[1888,1310],[1880,1310],[1880,1347],[1868,1347],[1868,1310],[1846,1310],[1846,1347],[1834,1347],[1834,1310],[1823,1310],[1823,1266],[1834,1266]],"historicalInterpretation":"NIST shows only the lower C414/C415 stems and one connecting spandrel fragment. The upper FEMA piece and the C416 continuation lie in the unshaded NIST opening. The white interiors of the two outlined stems and spandrel are retained plate faces, not window holes.","priorSource":"FEMA403 Fig2-27 p2-30","retainedHoles":[],"sourceColorPolicy":"Preserve existing panel grouping color; color is not a damage class. This operation replaces geometry provenance with the stated NIST observed source."}],"afterArea":3.6683765608540146},{"id":"WTC2-S-C417-419-F79.4-82.4","beforeArea":15.118806790750067,"baselineRegionsSha256":"11c4598d5638f090e70cb022c2d2a02a1b0775b4d423d7dc14b79917be19e423","operations":[{"id":"WTC2-S-C417-419-F79.4-82.4-NIST7-25-intersection","targetPanelId":"WTC2-S-C417-419-F79.4-82.4","operation":"intersection","polygon":[[43.236715,80.133065],[44.492754,80.116935],[44.009662,79.762097],[44.782609,79.721774],[43.913043,79.737903],[43.52657,79.46371],[42.463768,79.479839],[42.657005,79.649194],[40.531401,79.431452],[39.563107,79.447581],[42.850242,79.810484]],"sourceBoundaryPixels":[[1770,1384],[1783,1386],[1778,1430],[1786,1435],[1777,1433],[1773,1467],[1762,1465],[1764,1444],[1742,1471],[1732,1469],[1766,1424]],"historicalInterpretation":"NIST retains a small bent lower fragment near C417/C418. The higher FEMA-retained material lies in the unshaded opening. Preserve both the tilted stem and its diagonal connected portion; do not remove the whole panel. This polyline follows the centers of source outline strokes, with the short rightward stub approximated within raster uncertainty.","priorSource":"FEMA403 Fig2-27 p2-30","retainedHoles":[],"sourceColorPolicy":"Preserve existing panel grouping color; color is not a damage class. This operation replaces geometry provenance with the stated NIST observed source."},{"id":"WTC2-S-C417-419-F79.4-82.4-NIST7-25-union","targetPanelId":"WTC2-S-C417-419-F79.4-82.4","operation":"union","polygon":[[43.236715,80.133065],[44.492754,80.116935],[44.009662,79.762097],[44.782609,79.721774],[43.913043,79.737903],[43.52657,79.46371],[42.463768,79.479839],[42.657005,79.649194],[40.531401,79.431452],[39.563107,79.447581],[42.850242,79.810484]],"sourceBoundaryPixels":[[1770,1384],[1783,1386],[1778,1430],[1786,1435],[1777,1433],[1773,1467],[1762,1465],[1764,1444],[1742,1471],[1732,1469],[1766,1424]],"historicalInterpretation":"NIST retains a small bent lower fragment near C417/C418. The higher FEMA-retained material lies in the unshaded opening. Preserve both the tilted stem and its diagonal connected portion; do not remove the whole panel. This polyline follows the centers of source outline strokes, with the short rightward stub approximated within raster uncertainty.","priorSource":"FEMA403 Fig2-27 p2-30","retainedHoles":[],"sourceColorPolicy":"Preserve existing panel grouping color; color is not a damage class. This operation replaces geometry provenance with the stated NIST observed source."}],"afterArea":1.1426778280928105},{"id":"WTC2-S-C432-434-F76.4-79.4","beforeArea":8.999494882300024,"baselineRegionsSha256":"57e702b4d0665499955aa008112ca398c53de35cc25c1928494851a3c0ec292f","operations":[{"id":"WTC2-S-C432-434-F76.4-79.4-NIST7-25-intersection","targetPanelId":"WTC2-S-C432-434-F76.4-79.4","operation":"intersection","polygon":[[-13.834951,78.141379],[-12.76699,78.203448],[-12.76699,78.072414],[-10.533981,78.072414],[-10.533981,78.141379],[-9.468599,78.141379],[-9.468599,78.072414],[-7.246377,78.072414],[-7.246377,78.775862],[-6.859903,78.775862],[-6.086957,78.734483],[-6.086957,78.072414],[-5.31401,78.072414],[-5.31401,77.729839],[-6.086957,77.729839],[-6.086957,77.431452],[-7.246377,77.431452],[-7.246377,77.729839],[-9.468599,77.729839],[-9.468599,77.431452],[-10.533981,77.431452],[-10.533981,77.729839],[-12.76699,77.729839],[-12.76699,77.431452],[-13.834951,77.431452],[-13.834951,77.729839],[-15.0,77.729839],[-15.0,78.072414],[-13.834951,78.072414]],"sourceBoundaryPixels":[[1180,1649],[1191,1640],[1191,1659],[1214,1659],[1214,1649],[1225,1649],[1225,1659],[1248,1659],[1248,1557],[1252,1557],[1260,1563],[1260,1659],[1268,1659],[1268,1703],[1260,1703],[1260,1740],[1248,1740],[1248,1703],[1225,1703],[1225,1740],[1214,1740],[1214,1703],[1191,1703],[1191,1740],[1180,1740],[1180,1703],[1168,1703],[1168,1659],[1180,1659]],"historicalInterpretation":"The NIST lower-edge drawing has three distinct fracture tops: the C432 right stem extends much higher, while C433 and C434 end close above the floor78 spandrel. The higher C433/C434 FEMA remnants are absent in this later unshaded observation schematic. Keep the spandrel and all source-visible lower stems.","priorSource":"FEMA403 Fig2-27 p2-30","retainedHoles":[],"sourceColorPolicy":"Preserve existing panel grouping color; color is not a damage class. This operation replaces geometry provenance with the stated NIST observed source."},{"id":"WTC2-S-C432-434-F76.4-79.4-NIST7-25-union","targetPanelId":"WTC2-S-C432-434-F76.4-79.4","operation":"union","polygon":[[-13.834951,78.141379],[-12.76699,78.203448],[-12.76699,78.072414],[-10.533981,78.072414],[-10.533981,78.141379],[-9.468599,78.141379],[-9.468599,78.072414],[-7.246377,78.072414],[-7.246377,78.775862],[-6.859903,78.775862],[-6.086957,78.734483],[-6.086957,78.072414],[-5.31401,78.072414],[-5.31401,77.729839],[-6.086957,77.729839],[-6.086957,77.431452],[-7.246377,77.431452],[-7.246377,77.729839],[-9.468599,77.729839],[-9.468599,77.431452],[-10.533981,77.431452],[-10.533981,77.729839],[-12.76699,77.729839],[-12.76699,77.431452],[-13.834951,77.431452],[-13.834951,77.729839],[-15.0,77.729839],[-15.0,78.072414],[-13.834951,78.072414]],"sourceBoundaryPixels":[[1180,1649],[1191,1640],[1191,1659],[1214,1659],[1214,1649],[1225,1649],[1225,1659],[1248,1659],[1248,1557],[1252,1557],[1260,1563],[1260,1659],[1268,1659],[1268,1703],[1260,1703],[1260,1740],[1248,1740],[1248,1703],[1225,1703],[1225,1740],[1214,1740],[1214,1703],[1191,1703],[1191,1740],[1180,1740],[1180,1703],[1168,1703],[1168,1659],[1180,1659]],"historicalInterpretation":"The NIST lower-edge drawing has three distinct fracture tops: the C432 right stem extends much higher, while C433 and C434 end close above the floor78 spandrel. The higher C433/C434 FEMA remnants are absent in this later unshaded observation schematic. Keep the spandrel and all source-visible lower stems.","priorSource":"FEMA403 Fig2-27 p2-30","retainedHoles":[],"sourceColorPolicy":"Preserve existing panel grouping color; color is not a damage class. This operation replaces geometry provenance with the stated NIST observed source."}],"afterArea":5.280565147073503},{"id":"WTC2-S-C411-413-F81.4-84.4","beforeArea":16.96439171730001,"baselineRegionsSha256":"d945a5174780ffde926c14f0b6d2947ef35bb9352ef80208ce35c5257d0ce0c7","operations":[{"id":"WTC2-S-C411-413-F81.4-84.4-NIST7-25-clear-difference","targetPanelId":"WTC2-S-C411-413-F81.4-84.4","operation":"difference","polygon":[[54.541063,83.125],[58.309179,83.125],[58.309179,83.237903],[61.019417,83.237903],[61.019417,81.4],[54.541063,81.4]],"sourceBoundaryPixels":[[1887,1013],[1926,1013],[1926,999],[1954,999],[1954,1226.9],[1887,1226.9]],"historicalInterpretation":"Remove only the unshaded left portion below the source C413/C412 upper stub ends, before restoring the source-visible lower C412 piece. Native x is at most1954; the gray mask starts near1958 and is excluded. This bounded mask ends at nominal floor81.4; the original upper and right-side geometry is unchanged. No observed state is asserted inside gray.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."},{"id":"WTC2-S-C411-413-F81.4-84.4-NIST7-25-clear-union","targetPanelId":"WTC2-S-C411-413-F81.4-84.4","operation":"union","polygon":[[59.371981,82.633065],[60.533981,82.649194],[60.533981,82.092742],[61.019417,82.092742],[61.019417,81.729839],[60.533981,81.729839],[60.533981,81.4],[59.371981,81.4]],"sourceBoundaryPixels":[[1937,1074],[1949,1072],[1949,1141],[1954,1141],[1954,1186],[1949,1186],[1949,1226.9],[1937,1226.9]],"historicalInterpretation":"Restore the continuous lower C412 stem and the visible part of its floor82 spandrel. NIST depicts a sloped upper cap at native y1072\u20131074 and no interior break in this lower stem. White within its outline is retained steel. This local polygon stops before the gray region; it does not reconstruct C411 through smoke.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."}],"afterArea":12.361612383287993},{"id":"WTC2-S-C423-425-F77.4-80.4","beforeArea":11.408606468250069,"baselineRegionsSha256":"38d92a0227def2cd8725185b40477ada5c5521a74065f2acb246a2dee2a16ea0","operations":[{"id":"WTC2-S-C423-425-F77.4-80.4-NIST7-25-clear-difference","targetPanelId":"WTC2-S-C423-425-F77.4-80.4","operation":"difference","polygon":[[14.514563,80.004032],[25.432692,80.004032],[25.432692,78.7],[14.514563,78.7]],"sourceBoundaryPixels":[[1473,1400],[1586,1400],[1586,1568],[1473,1568]],"historicalInterpretation":"Replace only the broken upper part above the source floor79 spandrel lower boundary. The source C423 top is near native1495, substantially below the FEMA remnant; the left broken edge also slopes differently. Retain the existing lower stems, floor78 spandrel and lower windows.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."},{"id":"WTC2-S-C423-425-F77.4-80.4-NIST7-25-clear-union","targetPanelId":"WTC2-S-C423-425-F77.4-80.4","operation":"union","polygon":[[14.805825,78.872414],[17.621359,78.872414],[19.368932,79.020161],[19.368932,79.116935],[20.528846,79.133065],[20.528846,79.052419],[22.740385,79.092742],[22.740385,79.221774],[23.894231,79.237903],[23.894231,79.092742],[25.240385,79.092742],[25.240385,78.7],[14.805825,78.7]],"sourceBoundaryPixels":[[1476,1543],[1505,1543],[1523,1522],[1523,1510],[1535,1508],[1535,1518],[1558,1513],[1558,1497],[1570,1495],[1570,1513],[1584,1513],[1584,1568],[1476,1568]],"historicalInterpretation":"Restore the NIST-observed broken upper plate and short C424/C423 protruding stems. The top climbs diagonally from the C425 end toward C424, then slopes to C423; white enclosed between this top and the lower horizontal border is retained spandrel plate, not an opening. Curvature is simplified within raster-stroke precision; no 3D displacement is inferred.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."}],"afterArea":10.39647667564204},{"id":"WTC2-S-C429-431-F78.4-81.4","beforeArea":12.090787423699998,"baselineRegionsSha256":"202501dfc9d2f0881058dffeba323377febbf0f0db7344bc9aefd17890faa2ba","operations":[{"id":"WTC2-S-C429-431-F78.4-81.4-NIST7-25-clear-difference","targetPanelId":"WTC2-S-C429-431-F78.4-81.4","operation":"difference","polygon":[[-5.1,78.4],[5.1,78.4],[5.1,79.0],[-5.1,79.0]],"sourceBoundaryPixels":[[1270.215000000001,1611.499999999999],[1375.784999999999,1611.499999999999],[1375.784999999999,1524.5],[1270.215000000001,1524.5]],"historicalInterpretation":"NIST shows an unshaded white opening above the three lower green panel caps. Remove the three isolated FEMA remnants assigned to this upper gold panel at C429/C430/C431, which extend to floors78.689/78.607/78.756. The bounding operation starts at nominal floor78.4 and ends79.0, below the upper hanging region (minimum79.33895), so it leaves that region and the separate lower green panel unchanged. Independently reviewed from registered original source.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."}],"afterArea":11.230360095699996},{"id":"WTC2-S-C426-428-F76.4-79.4","beforeArea":8.294755843000033,"baselineRegionsSha256":"97c7e69019d78033cb523224bc2eebb3abf7b3a5d1469b588a0a6ac318351f95","operations":[{"id":"WTC2-S-C426-428-F76.4-79.4-NIST7-25-clear-difference","targetPanelId":"WTC2-S-C426-428-F76.4-79.4","operation":"difference","polygon":[[4.830918,79.358871],[15.194175,79.358871],[15.194175,78.67931],[4.830918,78.67931]],"sourceBoundaryPixels":[[1373,1480],[1480,1480],[1480,1571],[1373,1571]],"historicalInterpretation":"Replace only the unshaded broken upper band. NIST has a left-displaced C428 cap and curved retained edge toward C427, no isolated high C427 tip, and a lower square C426 fragment. All original lower geometry below native y1571 remains unchanged.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."},{"id":"WTC2-S-C426-428-F76.4-79.4-NIST7-25-clear-union","targetPanelId":"WTC2-S-C426-428-F76.4-79.4","operation":"union","polygon":[[5.024155,79.068548],[6.183575,79.068548],[6.570048,78.955172],[7.149758,78.851724],[7.922705,78.768966],[8.599034,78.72069],[9.371981,78.67931],[5.024155,78.67931]],"sourceBoundaryPixels":[[1375,1516],[1387,1516],[1391,1531],[1397,1546],[1405,1558],[1412,1565],[1420,1571],[1375,1571]],"historicalInterpretation":"Restore the left-displaced C428 top and the retained face below its curved edge toward C427. This manually sampled polyline approximates the visible curve; it is not a measured three-dimensional bend. The broad enclosed white region is retained steel face.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."},{"id":"WTC2-S-C426-428-F76.4-79.4-NIST7-25-clear-union-right-fragment","targetPanelId":"WTC2-S-C426-428-F76.4-79.4","operation":"union","polygon":[[12.864078,78.872414],[15.097087,78.872414],[15.097087,78.7],[14.029126,78.7],[14.029126,78.67931],[12.864078,78.67931]],"sourceBoundaryPixels":[[1456,1543],[1479,1543],[1479,1568],[1468,1568],[1468,1571],[1456,1571]],"historicalInterpretation":"Restore the source-visible short square C426 fragment, keeping the true white opening between it and the left C428/C427 fragment. The short lower stem joins the untouched original lower C426 member.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."}],"afterArea":8.132353196102544},{"id":"WTC2-S-C435-437-F77.4-80.4","beforeArea":17.695652342050128,"baselineRegionsSha256":"50cdbcad5dd14948dfa9a745b240c241dca447332e8d1d820dcb890e4f88c711","operations":[{"id":"WTC2-S-C435-437-F77.4-80.4-NIST7-25-clear-difference-C435-gap","targetPanelId":"WTC2-S-C435-437-F77.4-80.4","operation":"difference","polygon":[[-17.718447,78.437931],[-15.582524,78.437931],[-15.582524,78.27931],[-17.718447,78.27931]],"sourceBoundaryPixels":[[1140,1606],[1162,1606],[1162,1629],[1140,1629]],"historicalInterpretation":"The unshaded NIST C435 stem has a distinct upper hanging end cap near native y1606 and separate lower cap near1629. Cut only this observed gap; preserve the original stem alignment and all surrounding plates. Boundary uncertainty is approximately2pixels.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."},{"id":"WTC2-S-C435-437-F77.4-80.4-NIST7-25-clear-difference-C436-gap","targetPanelId":"WTC2-S-C435-437-F77.4-80.4","operation":"difference","polygon":[[-21.014493,78.375862],[-18.980583,78.375862],[-18.980583,78.251724],[-21.014493,78.251724]],"sourceBoundaryPixels":[[1106,1615],[1127,1615],[1127,1633],[1106,1633]],"historicalInterpretation":"The unshaded NIST C436 stem has separate end caps near native y1615 and1633. Cut only this observed gap. C437 is not changed: a dotted aluminum-cladding mark crosses it, without an independently visible severed-cap pair that would establish the same gap.","priorSource":"FEMA403 Fig2-27 p2-30","partialAmendment":true,"sourceColorPolicy":"Keep existing panel grouping color. NIST observed source governs only the bounded area; retain original FEMA geometry and provenance elsewhere."}],"afterArea":17.369598456993852}]}