iPhasematch vs Orbit Map

iPhasematch allows you to calculate the phasematching condition of nonlinear wavelength conversion such as SHG or SFM based on published Sellmeier equiations. Downconversion (OPO) can be figured out by the reverse of SFM. It is a subset of the 'Qmix' function of a famous Windows software SNLO by Dr. Arlee Smith. This App does some of what SNLO does on your iOS device. It takes the crystal, two input wavelengths, and temperature and gives the phasematching orientations, effective nonlinear optical coefficients, walk-off angles, angular tolerance and temperature tolerance. In case of SHG, it also gives spectral tolerance. In biaxial crystals, it gives only the phasematching orientations in the principal planes, i.e., either theta=90 deg. or phi=0 or 90deg. Currently supported crystals: BBO, BiBO, CBO, CLBO, LB4, LBO, KBBF, KDP, KD*P, KN, KTP, Mg:LN, Mg:sLN, RBBF, RTP, YAB. NOTE: dn/dT data for LB4 was picked up from discrete data points in the reference and linearly extrapolated. Interface should be intuitive, giving phasematching with a tap of "PM" button,refractive index with "index" button and group index with "Gp.Idx" button, for the given condition (crystal, wavelengths, and temperature). DISCLAIMER: I cannot be held responsible for the result of the calculation it gives. I make every effort to make it accurate, and bug-free, but there could be errors in code. Please just use this on your own discretion.

Orbit Map is a working atlas of everything humanity has left in orbit. Around 31,900 tracked objects, propagated on your device with the same SGP4/SDP4 model the industry uses, drawn on a real 3D Earth you can turn in your hands. Point it at tonight and it tells you when the Space Station crosses your roof. Search a name or a NORAD number and the orbit appears. Tap one group and ten thousand Starlink satellites light up at once. WHAT YOU CAN SEE • Every catalogued object: payloads, spent rocket stages and debris • Live positions from public orbital elements, computed offline on your device • Orbit paths, ground tracks and the horizon footprint of any spacecraft • Starlink, GPS, Galileo, GLONASS, OneWeb, weather satellites, debris shells • Altitude, speed, period, inclination, apogee, perigee, country, launch year • Filter and colour the field by object type, altitude, country or status • Detailed 3D models of real spacecraft families • Run time forward and back, or freeze the atlas and read it PASSES OVER YOUR HEAD • When the Station, Tiangong or Hubble crosses your sky • Rise, peak and set with azimuth and elevation for each pass • Sunlight and darkness checked, because a pass you cannot see is not a pass • Any place on Earth as your observing point, with its own time zone • Notifications before something flies over THE ACADEMY 54 lessons, more than eight hours, written for this atlas rather than borrowed from a textbook. Every lesson carries measured numbers you can verify in the inspector, the misconception it exists to correct, two things to do on the globe, a comprehension check and the vocabulary it introduces. Nine modules, from the first question to responsible interpretation: orbital mechanics. Reading element sets. Orbit families. Real missions. Observing the sky. The space environment. Debris and safety. Signals and navigation. Data literacy. Sourced from NASA, ESA, CelesTrak and Space-Track. ON EVERY SCREEN YOU OWN iPhone, iPad, Mac, Apple TV and Apple Vision Pro. Lesson progress, observing places and display settings stay together through iCloud. HONEST ABOUT WHAT IT IS Orbit Map propagates public General Perturbations elements. Accuracy degrades as elements age and can differ by kilometres. Pass timing uses geometric sunlight and a 10° horizon; weather and apparent brightness are not modelled, so a sunlit pass is an opportunity rather than a promise. This is an educational atlas. It is not a conjunction assessment tool, not a navigation aid, and not for antenna pointing. Every screen states which snapshot it is using and how old the elements behind it are, because knowing the age of your data is part of reading it. WHERE THE DATA COMES FROM Public GP elements from Space-Track.org and USSPACECOM, cross-checked against an independent CelesTrak set before any release ships. Positions come from a Vallado-compatible SGP4/SDP4 implementation verified against the published reference vectors. Catalogue updates are signed and every byte is checked before it replaces what you already have. PREMIUM The free atlas is complete and accurate: the whole globe, the entire catalogue, search, orbit paths, and passes for the Station, Tiangong and Hubble. Premium opens all 54 lessons, every constellation, the full Orbital Lens, seven-day forecasts from up to ten saved places, pass notifications, every spacecraft model, the time machine and iCloud sync. Subscription Terms: Payment charged to iTunes Account. Auto-renews unless disabled 24 hours before period ends. Manage in Account Settings. https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Data provided by Space-Track.org and USSPACECOM. Validation data provided by CelesTrak, Dr. T.S. Kelso. Earth imagery courtesy of NASA.