CASS - Telescope Design Program, SPP Version of 28-AUG-07 Executed on: Tue 16:00:39 28-Aug-2007 Parameters based on third order aberration calculations. LBT F/15 BENT GREGORIAN FOCUS (infrared, case D, new BFD) telescope input parameters 3. number of mirrors in optical train 3. gregorian configuration 8.408 primary mirror diameter (m) 1.14177 primary focal ratio -14.7204 system focal ratio 5.3 axis -- focus distance (m) INDEF secondary focal length (m) 4. field diameter (arcmin) 0.898 primary obstruction (m) 40. maximum infrared wavelength (microns) 3.7 tolerable diffraction radius 7.000000E-4 infrared centration allowance (m) 2.25 height of tertiary above vertex (m) 1.00029 refractive index of air other telescope parameters 9.600002 primary focal length (m) solving based on fs and eve 3.05 effective vertex distance (m) -12.89261 magnification of secondary -123.7691 system focal length (m) 0.002445788 throughput (ubar1*y1) -0.03396647 telescope numerical aperture -0.03396315 half angle of telescope light cone (in air, rad) 0.7853982 tertiary tilt angle from optical axis (rad) 5.3 pathlength from tertiary to focus (m) 10.66369 separation of m1 and m2 (m) 13.71369 pathlength from secondary to focus (m) 0.7775945 l = separation / back focal distance 0.3177083 beta = vertex distance / focal length of m1 0.3627498 eta = normalized vertex back focus 0.01140689 specified central obstruction (fractional area) 0.9871208 focal length of secondary (m) 96.24219 entrance pupil position relative to primary (m) -9.025225 entrance pupil magnification, paraxial 0.9442862 vertex diameter of secondary (m) 0.0126131 obscuration by secondary (fractional area) 0.9318784 vertex diameter of beam at secondary (m) 0.1749726 ?exit pupil throughput (ubar*y) for secondary -1. primary asphere fixed -0.7328021 secondary asphere for cass 1. primary eccentricity 0.8560386 secondary eccentricity normalized structural aberration coefficients -1.575118E-14 sigmai -1. sigmaii -9.80282 sigmaiii 138.2766 sigmaiv -22.57252 sigmav primary mirror parameters 0.4602503 sagitta of primary mirror (m) -5652.75 primary aspheric amplitude (microns) 0.4311129 half angle of primary light cone (rad) 0.4180033 primary numerical aperture 1.196163 ??primary focal ratio apparently secondary mirror parameters 0.9404014 edge diameter of secondary mirror (m) 1.04968 secondary focal ratio 0.05620711 sagitta of secondary mirror (m) 0.9145526 *infrared vertex diameter of secondary mirror (m) 8.254044 *entrance pupil diameter, paraxial (m) (using chief rays through secondary vertex) -0.01240776 field correction to m2 diameter (m) -0.0014 centration correction to m2 diameter (m) 1.624639E-4 infrared diffraction angle (radians) -0.003515957 diffraction correction to m2 diameter (m) 0.9109714 infrared edge diameter of secondary mirror (m) 1.083591 infrared secondary focal ratio 0.0527317 sagitta of secondary mirror (m) 8.251091 effective primary aperture (m) 15.00001 effective system focal ratio 8.362538 effective primary envelope (m) 100.7615 ??entrance pupil position relative to primary (m) -9.495984 ??entrance pupil magnification 8.65057 ??entrance pupil diameter, from edge (m) -530.295 secondary aspheric amplitude (microns) 0.1182378 infrared unused hole in secondary (m) -12.89261 ??magnification by focal length -12.89261 ??magnification by image distance -12.69355 ??magnification by angle U -13.53796 ??magnification by tangent U -12.30635 ??magnification by numerical aperture tertiary mirror parameters 0.3601479 diameter of beam at tertiary (m) 0.08835412 field correction to tertiary diameter (m) 0.448502 minor axis diameter of tertiary (m) 0.4578008 upper tertiary minor axis diameter (m) 0.4395734 lower tertiary minor axis diameter (m) 0.006444376 offset of the tertiary ellipse (m) 0.4486871 corrected minor axis diameter of tertiary (m) 0.6345394 major axis diameter of tertiary (m) 0.001366921 diffraction correction to m3 diameter (m) 0.0014 centration correction to m3 diameter (m) 0.451454 infrared minor axis diameter of tertiary (m) 0.6384524 infrared major axis diameter of tertiary (m) 0.6789233 hole in converging light above tertiary (m) 0.0126131 fractional area of telescope obscuration 52.76998 net telescope collecting area (m**2) wavefront aberration coefficients 8.109179E-14 w040 (microns) spherical aberration -0.7054392 w131 (microns) coma 0.2368898 w222 (microns) astigmatism -1.67076 w220p (microns) field curvature -0.01868577 w311 (microns) distortion focal plane parameters 0.6000496 platescale (mm/arcsec) 5.817764E-4 field radius angle (ubar1), (rad) 0.1440119 linear diameter of focal plane (m) 0.047 rms angular image radius tolerance (arcsec) 28.20233 rms physical image radius tolerance (microns) 1.520967 fractional curved field radius 6.083869 maximum curved field diameter (arcmin) -0.8950837 ?petzval radius of curvature (m) -1.042961 focal plane radius of curvature (m) 0.8939903 fractional flat field radius 3.575961 maximum flat field diameter (arcmin) 1.17422 height of largest flat field (mm) -0.550124 full field distortion (microns) field focus curve for aligned system radius focal plane height image size wave aberration (mm) (arcmin) (mm) (+/-mm) (micron) (arcsec) (micron rms) 0.00 0.00 -1.874E-13 1.17 1.59E-12 2.65E-15 9.87E-15 3.60 0.10 0.006214 1.17 0.848 0.00141 0.00416 7.20 0.20 0.02486 1.17 1.7 0.00283 0.00833 10.80 0.30 0.05593 1.17 2.55 0.00424 0.0125 14.40 0.40 0.09943 1.17 3.4 0.00566 0.0168 18.00 0.50 0.1554 1.16 4.25 0.00708 0.0211 21.60 0.60 0.2237 1.15 5.11 0.00851 0.0255 25.20 0.70 0.3045 1.15 5.97 0.00994 0.03 28.80 0.80 0.3977 1.14 6.83 0.0114 0.0346 32.40 0.90 0.5033 1.13 7.7 0.0128 0.0393 36.00 1.00 0.6214 1.12 8.57 0.0143 0.0441 39.60 1.10 0.7519 1.11 9.45 0.0157 0.0491 43.20 1.20 0.8948 1.09 10.3 0.0172 0.0542 46.80 1.30 1.05 1.08 11.2 0.0187 0.0596 50.40 1.40 1.218 1.06 12.1 0.0202 0.065 54.00 1.50 1.398 1.04 13. 0.0217 0.0707 57.60 1.60 1.591 1.02 13.9 0.0232 0.0766 61.21 1.70 1.796 0.998 14.8 0.0247 0.0826 64.81 1.80 2.013 0.973 15.8 0.0263 0.0889 68.41 1.90 2.243 0.946 16.7 0.0279 0.0954 72.01 2.00 2.486 0.916 17.7 0.0294 0.102 secondary alignment tolerances based on rms image radius 0.09588546 wavefront focus -- axial motion (micron/micron) 7.064276 m2 focus tolerance (on-axis) -- axial motion (micron) 5.507792 m2 focus tolerance (field) -- axial motion (micron) -9.456429E-6 scale change without refocus (fraction/micron) -1.306083E-5 scale change with refocus (fraction/micron) 0.004568509 wavefront spherical ab'n -- axial motion (micron/micron) 0.08966701 induced image radius (micron/micron) 1.494327E-4 induced image radius (arcsec/micron) 314.5229 tolerable secondary motion (micron) 27.48479 wavefront spherical ab'n -- focal motion (micron/meter) -0.05227985 tolerable focal plane motion (m) 0.01103283 wavefront spherical ab'n -- primary asphere (micron/ppm) 0.2165435 induced image radius (micron/ppm) 3.608759E-4 induced image radius (arcsec/ppm) 1.302387E-4 tolerable primary asphere error 0.001529529 wavefront spherical ab'n -- secondary asphere (micron/ppm) 0.03002037 induced image radius (micron/ppm) 5.002981E-5 induced image radius (arcsec/ppm) 9.394400E-4 tolerable secondary asphere error 1.063686 distance from m2 to zero-coma pivot (m) 0. distance from prime focus to zero-coma pivot (m) -0.1022064 image motion from zero-coma rotation (arcsec/arcsec) -0.2216011 image motion from m2 vertex rotation (arcsec/arcsec) 13.89261 image motion from lateral displacement (micron/micron) 0.02315244 image motion from lateral displacement (arcsec/micron) 0.02098232 wavefront coma -- lateral motion (micron/micron) 0.5043794 induced image radius (micron/micron) 8.405629E-4 induced image radius (arcsec/micron) 55.91491 tolerable motion (micron) 0.1082036 wavefront coma -- vertex rotation (micron/arcsec) 2.601031 induced image radius (micron/arcsec) 0.004334693 induced image radius (arcsec/arcsec) 10.84275 tolerable rotation (arcsec) -0.4882808 wavefront coma -- vertex chop angle (micron/arcsec) -11.73745 induced image radius (micron/arcsec) -0.01956079 induced image radius (arcsec/arcsec) -2.402766 tolerable vertex chop throw (arcsec) 74.90606 tolerable zero coma chop throw (arcsec), astig only 0.9765616 wavefront coma -- primary rotation (micron/arcsec) 23.47489 induced image radius (micron/arcsec) 0.03912158 induced image radius (arcsec/arcsec) 1.201383 tolerable rotation (arcsec) tertiary alignment tolerances 0.08564333 image motion from tertiary rotation (arcsec/arcsec) Writing OSLO format input file: ybg15.len Deleting existing output file.