Aurora Forecast 3D vs Cyanometer

The Aurora Forecast 3D is a tool to track down where the aurora is located in the sky from any location on planet. It renders Earth in 3D with rotation and scaling at your fingertips. You can select locations and make your own ground - station list. The Sun illuminates the globe as it updates in near real-time. The short term forecasts are up to +6 hours, while the long term forecasts are up to 3 days ahead in time. They are updated when the app is active and connected to internet. An Aurora Compass is included that shows where the auroral oval [1,2], the Moon and the Sun are located as you look up at the sky from your location. The phase and age of the Moon is also visualized in the compass. By zooming out in the 3D view port, satellites, stars and planets appear in their orbits [3] around the Sun. FEATURES - 3D view port of Earth. - Solar illumination of the Earth and the Moon. - Aurora oval size and location in real time. - Day side location of the red Cusp. - Forecasts based on predicted Kp index estimated by the Space Weather Prediction Centre (NOAA-SWPC). - Includes a 2.4 million star map [4]. - City light texture [5]. - Earth, Sun and Moon textures [6,7]. - Sky view module to track planets and stars [8]. - 3-day space weather condition forecast as news ticker. - Two-Line Element (TLE) satellite orbit calculations [9]. - Skyview navigation. - 3D Laser Star pointer to identify star signs. - Sounding rocket trajectories. - Sun and Moon daily elevation plots with rise and set time. - Epoch selection for magnetic pole position [10] - Ovals based on polar orbiting satellites data [11] - Target web links added to satellites, stars, planets and position. - All-sky camera links to the Boreal Aurora Camera Constellation (BACC). - Sky color animation [12,13]. - Zhang and Paxton ovals [14]. - Earth shadow calculations in twilight - Youtube demonstration. References [1] Sigernes F., M. Dyrland, P. Brekke, S. Chernouss, D.A. Lorentzen, K. Oksavik, and C.S. Deehr, Two methods to forecast auroral displays, Journal of Space Weather and Space Climate (SWSC), Vol. 1, No. 1, A03, DOI:10.1051/swsc/2011003, 2011. [2] Starkov G. V., Mathematical model of the auroral boundaries, Geomagnetism and Aeronomy, 34 (3), 331-336, 1994. [3] P. Schlyter, How to compute planetary positions, http://stjarnhimlen.se/, Stockholm, Sweden. [4] Bridgman, T. and Wright, E., The Tycho Catalog Sky map- Version 2.0, NASA/Goddard Space Flight Center Scientific Visualization Studio, http://svs.gsfc.nasa.gov/3572, January 26, 2009. [5] The Visible Earth catalog, http://visibleearth.nasa.gov/, NASA/Goddard Space Flight Center, April-October, 2012. [6] T. Patterson, Natural Earth III - Texture Maps, http://www.shadedrelief.com, October 1, 2016. [7] Nexus - Planet Textures, http://www.solarsystemscope.com/nexus/, January 4, 2013. [8] Hoffleit, D. and Warren, Jr., W.H., The Bright Star Catalog, 5th Revised Edition (Preliminary Version), Astronomical Data Center, NSSDC/ADC, 1991. [9] Vallado, David A., Paul Crawford, Richard Hujsak, and T.S. Kelso, Revisiting Spacetrack Report #3, AIAA/AAS-2006-6753, https://celestrak.com, 2006. [10] Tsyganenko, N.A., Secular drift of the auroral ovals: How fast do they actually move?, Geophysical Research Letters, 46, 3017-3023, 2019. [11] M. J. Breedveld, Predicting the Auroral Oval Boundaries by Means of Polar Operational Environmental Satellite Particle Precipitation Data, Master thesis, Department of Physics and Technology, Faculty of Science and Technology, The Arctic University of Norway, June 2020. [12] Perez, R., J,M. Seals and B. Smith, An all-weather model for sky illuminance distribution, Solar Energy, 1993. [13] Preetham, A.J, P. Shirley and B. Smith, A practical model for daylight Computer Graphics, (SIGGRAPH 99 Proceedings), 91-100, 1999. [14] Zhang Y., and L. J. Paxton, An empirical Kp-dependent global auroral model based on TIMED/GUVI data, J. Atm. Solar-Terr. Phys., 70, 1231-1242, 2008.

The original cyanometer was invented by the Genevan physicist and Alpine explorer Horace-Bénédict de Saussure (* 17 February 1740 in Conches; † 22 January 1799) in 1789. It is an instrument for measuring 'blueness', specifically the colour intensity of blue sky. With the measurement it is possible to draw conclusions from the constitution of the atmosphere: the bluer the sky the less the water vapor. Saussures cyanometer consisted out of 53 parts of a circular ring ranging from white over different grades of blue to black (Saussure used Prussian blue). Saussure used his cyanometer for measurements in Geneva, Chamonix und on the Mont Blanc. Alexander von Humboldt used a cyanometer on his expedition to America (1799 - 1804). You can use our Cyanometer in three modes: The modern scale uses distinct grades of blue starting with clear white up to black. The Saussure scale shall give an idea about the colors from Saussures original cyanometer. With the user defined scale own scans of blue skies can be added to an own colored circular ring - an own cyanometer. Each scan is saved inside the app containing information about date, time and locality. So it is possible to compare scans of blue skies from different locations. Privacy notice: No data will be saved or processed outside the app.