:orphan: .. **************************************************************************** .. CUI .. .. The Advanced Framework for Simulation, Integration, and Modeling (AFSIM) .. .. The use, dissemination or disclosure of data in this file is subject to .. limitation or restriction. See accompanying README and LICENSE for details. .. **************************************************************************** .. demo:: satellite_demos .. |classification| replace:: Unclassified .. |date| replace:: 2014-10-08 .. |group| replace:: Demos .. |image| replace:: images/satellite_demos.png .. |tags| replace:: n/a .. |title| replace:: satellite_demos .. |startup| replace:: 1st_comsat_demo.txt .. |summary| replace:: This directory contains various examples and demonstrations of WSF's satellite capability and satellite interaction with other platforms and the overall environment. .. |i| image:: images/satellite_demos.png :height: 150 px :width: 150 px .. include:: demo_template.txt | This directory contains various examples and demonstrations of AFSIM's | satellite capability and satellite interaction with other platforms | and the overall environment. | | Following are the top-level files to be loaded and run in the AFSIM Wizard. 1st_comsat_demo.txt ------------------- | This example uses the amateur radio satellite AO-51 (Echo) to simulate a | standard communications satellite. Transmitters on the ground use it as | a relay to communicate between themselves. | The transmit/receive parameters were retrieved from the AO-51 link budget | on the website 'www.amsat.org'. The debug output was verified against the | results of the calculator. | | Note that the satellite will be available to both ground stations only during | the time from about 420 sec to 980 sec and in some cases the S/N may be | too low. | | Message traffic is generated by having a sensor produce tracks. The | sensor will 'detect' the satellite and then attempt to send the track | to the other ground stations. 2nd_gps_demo.txt ---------------- | This example demonstrates a GPS constellation and its availability | to be seen from a specified location on the earth. 3rd_background_sats.txt ----------------------- | This example places over 600 distinct satellites in orbit. | | The TLE's were retrieved from http://celestrak.com using the Perl script | "download_tle.pl" This script may be re-run as needed to update the TLE | definitions to the current time. 4th_constellation_demo.txt -------------------------- | This example demonstrates how to easily create a notional satellite | constellation with only a basic understanding of orbital elements. 5th_iridium_flares_demo.txt --------------------------- | Iridium Flares are very localized events that look like flares | or shooting stars: they become very bright and then fade away | over a period of about ten seconds. Some flares are 100x brighter than | the brightest star. They are caused by specular reflection by the sun | from the Iridium Satellites solar panels and main communications antennae, | which look like shiny flat plates that act like mirrors. | This demo computes flare locations for the entire Iridium satellite | constellation. Lines are drawn from the satellites to the approximate flare | location on the ground. A platform is created and moved across the ground | to visualize the flare's ground track. | If you want to use this as a tool to see the flares, change the lat/lon/alt | defined in script_variables, below, to your location; then set the | GMT_Offset to the correct offset for your time zone. Either use the | "start_time_now" setting to get a current report, or set the start_date and | start_time to the desired observing date and time (keep in mind that the time | is UT, not local time). | Update the iridium platforms list by running the "download_tle.pl" | Perl script, which will automatically update all major TLE lists from the | Celestrack website, including the Iridium satellite TLEs | (see http://www.celestrak.com/NORAD/elements/iridium.txt). | When you run this demo, a custom file gives a report of nearby flares | and local az/el locations of the satellites. You can also try tethering to | the "center" platform in Mystic and pan around to visualize | the satellite's location relative to your viewing location. 6th_Hohmann_leo_orbit_transfer_demo.txt --------------------------------------- | This example demonstrates a Hohmann transfer to a satellite in LEO. | | There are two burns in a Hohmann transfer, the first one is critically | timed so the apogee of the transfer orbit coincides with the | final orbit. The second burn is performed at apogee, at the | time of rendezvous. After both burns, the two satellites are in | the same orbit with the same "phase" (anomaly). GPS_denied_demo.txt ------------------- | In this demo, a fighter bomber fires two missiles at a ground radar site. | When the radar site begins to track the incoming missiles, it begins to | jam the GPS signal going to the missiles. The GPS on-board the missiles | is then denied and they revert back to ins errors, | which ultimately leads to their missing the target. iridium_demo.txt ---------------- | This example demonstrates how a person in India can call a person in Paraguay | at the same time someone in Oklahoma calls a person in Chad. Both calls | take the path with fewest hops between satellites. These paths update | as the satellites move in and out of range. aerobraking_demo.txt -------------------- | This example demonstrates the use of the :model:`WSF_INTEGRATING_SPACE_MOVER` | to set up dynamics that include atmospheric drag. This scenario includes | one platform on an orbit starting near the Moon, and plunging into the | atmosphere of the Earth. The drag resulting from the operation slows the | platform down, and over a number of passes through the atmosphere, the | orbit apoapsis is significantly reduced.