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463 <?php // -------------------- Constants ----------------------------------------------------- // define ("earth_grav_const" , 3.986e5); // Earth's Gravitational Constant (Km^3/s^2) define ("eg_4pi" , 10096.66709265246); // Earth's Gravitational Constant / 4*pi^2 define ("sideral_day_sec" , 86164.0984); // One Earth Rotation in seconds define ("equatorial_radius", 6378.137); // WGS-84 define ("flattening" , 298.257223563); // 1/flattening per WGS-84 define ("ghaa_deg" , 99.4033); // The angle between the Greenwich meridian define ("date_of_GHAA" , "1/1/1990 00:00"); // and 'Aries' at this date in Degrees define ("Tropical_year" , 365.242197); // Tropical Year in days define ("c" , 2.99792458e5); // speed of light in Km/s // http://www.colorado.edu/geography/gcraft/notes/datum/elist.html // The amount the earth rotates during the 3 minutes and 5.59 seconds // difference between the 24 hrs (Solar) day and the sideral day $extra_earth_rot_per_day = (2 * M_PI) / Tropical_year; // The total earth rotation in one Solar Day = 1 sideral day + the above figure $earth_rot_rad_sec = ($extra_earth_rot_per_day + (2 * M_PI))/86400; // Earth Rotation Rate (radians/sec) // Initializing the Current Date Array $curr_date_array = getdate(); $curr_year = $curr_date_array ['year']; $curr_day = $curr_date_array ['yday'] + 1; // php counts days from 0, TLE epoch counts from 1 $curr_sec =($curr_date_array ['hours'] * 3600) + ($curr_date_array ['minutes'] * 60) + $curr_date_array ['seconds']; // - 3600; // Mysterious One Hour shift (20.10.03 - 26.10.03) Possible DST bug $curr_time_unix = $curr_date_array [0]; $curr_frac_day = $curr_sec / 86400; // This is how the sideral time appears in the TLEs, fraction of solar day // Bringing the RA in sync with the current time. // Seconds since reference GHAA was specified $delta_ghaa_sec = $curr_time_unix - (strtotime (date_of_GHAA)); // time is in sedconds since 1.1.70 (UNIX time) // The current Angle to Aries from the Greenwich meridian. // This is the X axis of the Geocentric Inertial coordinates (GHAA = Greenwich Hour Angle Aries) $current_ghaa_rad = deg2rad(ghaa_deg) + ($delta_ghaa_sec * $earth_rot_rad_sec); $cos_ghaa = cos(-$current_ghaa_rad); $sin_ghaa = sin(-$current_ghaa_rad); // Get the data from the form for Look Angles and range $do_look_angle = $_GET ['calc_ang']; $calc_range = $_GET ['calc_range']; $range_units = $_GET ['range_units']; $symbol_rate = $_GET ['sym_rate']; $sort_order = $_GET ['sort_order']; $use_cookie = $_GET ['use_cookie']; $bw = $_GET ['print']; if ($_GET ['round_trip'] == "TRUE") $round_trip = 2; else $round_trip = 1; $observer_site = $_GET ['loc_name']; $observer_lat = $_GET ['loc_lat']; $observer_long = $_GET ['loc_lon']; $observer_alt = $_GET ['loc_alt']; $observer_alt = $observer_alt/1000; $observer_lat_sign = $_GET ['lat_menu']; $observer_long_sign = $_GET ['lon_menu']; if ($observer_lat_sign == South) $observer_lat = -$observer_lat; if ($observer_long_sign == West ) $observer_long = -$observer_long; // Observer's UNIT vector In Geocentric Equatorial Coordinates // These are NOT Inertial coordinates, they are referenced to Greenwich $obs_lat_rad = deg2rad($observer_lat); $obs_long_rad = deg2rad($observer_long); $observer_up_x = cos($obs_lat_rad) * cos($obs_long_rad); $observer_up_y = cos($obs_lat_rad) * sin($obs_long_rad); $observer_up_z = sin($obs_lat_rad); $observer_east_x = -sin($obs_long_rad); $observer_east_y = cos($obs_long_rad); $observer_north_x= -sin($obs_lat_rad) * cos($obs_long_rad); $observer_north_y= -sin($obs_lat_rad) * sin($obs_long_rad); $observer_north_z= cos($obs_lat_rad); //Observer's XYZ coordinates on the surface of the earth. $polar_radius = equatorial_radius * (1 - (1/flattening)); $rx = ( pow(equatorial_radius,2) / sqrt( (pow(equatorial_radius,2) * pow(cos($obs_lat_rad),2) + (pow($polar_radius,2) * pow(sin($obs_lat_rad ),2))))); $rz = ( pow($polar_radius,2) / sqrt( (pow(equatorial_radius,2) * pow(cos($obs_lat_rad),2) + (pow($polar_radius,2) * pow(sin($obs_lat_rad ),2))))); $observer_x = $observer_up_x * ($rx + $observer_alt); $observer_y = $observer_up_y * ($rx + $observer_alt); $observer_z = $observer_up_z * ($rz + $observer_alt); if (!do_look_angle) $obs_elevation = 2; // To force printing if Look angles aren't calculated // Open the TLE file specified in the form from the page that invoked // the script, parse it and put it into an intermediate Array // 2010.3.22 - Hosting disabled access to off-site files, TLE file now hard coded to 'geo.txt' // $tle_url= $_GET ['tle_url']; $tle_data = fopen ('geo.txt',"r"); if (!$tle_data) nofile($tle_url); // File doesn't exist if (!$tle_data) return; $no_of_sat=0; while ((!feof ($tle_data)) and ($tle_data)) { $buffer1 = fgets($tle_data, 128); $buffer2 = fgets($tle_data, 128); $buffer3 = fgets($tle_data, 128); $raw_sat_ele[$no_of_sat] = array ('Name' => $buffer1, 'line1' => $buffer2, 'line2' => $buffer3); $no_of_sat++; } // -- Parsing the raw TLE data into elements -- // for ($i=0; $i<$no_of_sat; $i++) { $sat_name = substr ($raw_sat_ele [$i]['Name'], 0, 26 ); // $sat_cata = substr ($raw_sat_ele [$i]['line1'], 2, 5 ); $sat_launch_year = substr ($raw_sat_ele [$i]['line1'], 9, 2 ); // $sat_launch_no = substr ($raw_sat_ele [$i]['line1'], 11, 3 ); // $sat_payload_no = substr ($raw_sat_ele [$i]['line1'], 14, 1 ); $epoch_year = substr ($raw_sat_ele [$i]['line1'], 18, 2 ); $epoch_sider_day = substr ($raw_sat_ele [$i]['line1'], 20, 3 ); $epoch_sider_time = substr ($raw_sat_ele [$i]['line1'], 23, 9 ); $sat_inclination = substr ($raw_sat_ele [$i]['line2'], 8, 8 ); $sat_ra_asc_node = substr ($raw_sat_ele [$i]['line2'], 17, 8 ); $sat_eccentricity = substr ($raw_sat_ele [$i]['line2'], 26, 7 ); $sat_arg_perigee = substr ($raw_sat_ele [$i]['line2'], 34, 8 ); $sat_mean_anomaly = substr ($raw_sat_ele [$i]['line2'], 43, 8 ); $sat_mean_motion = substr ($raw_sat_ele [$i]['line2'], 52, 11 ); $sat_rev_at_epoch = substr ($raw_sat_ele [$i]['line2'], 63, 5 ); // And passing it to an "elements" Array $sat_elements [$i] = array ( 'Name' => $sat_name, 'Eccentricity' => $sat_eccentricity, 'Inclination' => $sat_inclination, 'Mean_anomaly' => $sat_mean_anomaly, 'Rev_at_epoch' => $sat_rev_at_epoch, 'Mean_motion' => $sat_mean_motion, 'Arg_perigee' => $sat_arg_perigee, 'RA_asc_node' => $sat_ra_asc_node, 'epoch_year' => $epoch_year, 'epoch_day' => $epoch_sider_day, 'epoch_time' => $epoch_sider_time ); }; // --------------------- Main Loop, passes through every TLE -------------------------- // for ($i=0; $i<$no_of_sat-1; $i++) { // Calculating elapsed time since epoch $ep_yr = $sat_elements [$i]['epoch_year']; if ($ep_yr>60) $ep_yr = $ep_yr + 1900; if ($ep_yr<60) $ep_yr = $ep_yr + 2000; $ep_dy = $sat_elements [$i]['epoch_day']; $ep_tm = $sat_elements [$i]['epoch_time']; $ep_tm_sec = $ep_tm * 86400; $ep_unix_y = getdate( mktime (0, 0, 0, 1, 1, $ep_yr) ); // Used to calculate time since epoch taking $ep_unix_s = $ep_unix_y[0] + (($ep_dy + $ep_tm) * 86400); // into account leap years $delta_sec = $curr_time_unix - $ep_unix_s; $delta_frac_yr = $delta_sec / (86400 * Tropical_year); // Calculating Axes of the elliptic orbit $mean_motion = $sat_elements [$i]['Mean_motion']; // Mean Motion in the TLE is given in Revolution / Day $period = ( 1 / $mean_motion) * (60 * 60 * 24); // Aug 2017 - Fixed and using solar day $seconds_pre_rev = $mean_motion * sideral_day_sec; // Number of seconds per revolution $eccentricity = $sat_elements [$i]['Eccentricity']; $eccentricity = $eccentricity/1e7; // Eccentricity in the TLEs assumes decimal point $semi_major_axis = pow((eg_4pi*pow($period, 2)),(1/3)); $semi_minor_axis = $semi_major_axis * sqrt(1-pow($eccentricity,2)); // Find the 'Eccentric Anomaly' by iterating (Newton's Method) // Mean Anomaly = Ecc Anomaly - (Eccentricity * Sin (Ecc Anomaly)) $mean_mot_rad_sec = ($mean_motion * 2 * M_PI) / 86400; // Mean Motion in RAD / sec $mean_anomaly_deg = $sat_elements [$i]['Mean_anomaly']; // Mean Anomaly in the TLE is given in Degrees $mean_anomaly_rad = deg2rad($mean_anomaly_deg); $rads_since_epoch = ($mean_mot_rad_sec * $delta_sec) + $mean_anomaly_rad; // (Mean Motion * Elapsed time) + Mean Anomaly $frac_rev = $rads_since_epoch - (2 * M_PI * ( floor( $rads_since_epoch / (2 * M_PI) ) )); // Do the iterations with this initial value $ecc_an = $frac_rev; do { $cos_ea = cos ($ecc_an); $sin_ea = sin ($ecc_an); $denom = 1 - ($cos_ea * $eccentricity); $iter = ( $ecc_an - ( $eccentricity * $sin_ea) - $rads_since_epoch ) / $denom; $ecc_an = $ecc_an - $iter; } while (abs($iter) > 0.0001); $sat_range = $semi_major_axis * $denom; // Satellite range from the CENTER of the earth // Calculating Satellite position vector on the Orbital Plane $sat_orb_plane_X = $semi_major_axis * ($cos_ea - $eccentricity); $sat_orb_plane_Y = $semi_minor_axis * $sin_ea; // Partial Rotation Matrix to transform from the Orbital Plane to Inertial (Celestial) Coordinates $incl = $sat_elements [$i]['Inclination']; $argpg = $sat_elements [$i]['Arg_perigee']; $raan = $sat_elements [$i]['RA_asc_node']; $cos_arg_per = cos (deg2rad($argpg)); $sin_arg_per = sin (deg2rad($argpg)); $cos_raan = cos (deg2rad($raan)); $sin_raan = sin (deg2rad($raan)); $cos_incl = cos (deg2rad($incl)); $sin_incl = sin (deg2rad($incl)); $cel_x_x = ( $cos_arg_per * $cos_raan) - ($sin_arg_per * $sin_raan * $cos_incl); $cel_x_y = (-$sin_arg_per * $cos_raan) - ($cos_arg_per * $sin_raan * $cos_incl); $cel_y_x = ( $cos_arg_per * $sin_raan) + ($sin_arg_per * $cos_raan * $cos_incl); $cel_y_y = (-$sin_arg_per * $sin_raan) + ($cos_arg_per * $cos_raan * $cos_incl); $cel_z_x = ( $sin_arg_per * $sin_incl); $cel_z_y = ( $cos_arg_per * $sin_incl); // Calculatins Satellite position vector in Celestial Coordinates $sat_celestial_X = ($sat_orb_plane_X * $cel_x_x) + ($sat_orb_plane_Y * $cel_x_y); $sat_celestial_Y = ($sat_orb_plane_X * $cel_y_x) + ($sat_orb_plane_Y * $cel_y_y); $sat_celestial_Z = ($sat_orb_plane_X * $cel_z_x) + ($sat_orb_plane_Y * $cel_z_y); // Satellite Coordinates in Geocentric Equatorial Coordinates (from RA to LONG, etc.) $sat_geoc_x = ( $sat_celestial_X * $cos_ghaa ) - ( $sat_celestial_Y * $sin_ghaa ); $sat_geoc_y = ( $sat_celestial_X * $sin_ghaa ) + ( $sat_celestial_Y * $cos_ghaa ); $sat_geoc_z = $sat_celestial_Z ; // Calculate Subsatellite Point $sub_sat_long = rad2deg(atan2($sat_geoc_y, $sat_geoc_x)); // East / West $sub_sat_lat = rad2deg(asin ($sat_geoc_z/$sat_range )); // North / South if ($do_look_angle) // Calculating Range Vector { $range_x = $sat_geoc_x - $observer_x; $range_y = $sat_geoc_y - $observer_y; $range_z = $sat_geoc_z - $observer_z; $range_magnitude = sqrt(pow($range_x,2)+pow($range_y,2)+pow($range_z,2)); $range_norm_x = $range_x / $range_magnitude; //Normalized Range Vector $range_norm_y = $range_y / $range_magnitude; $range_norm_z = $range_z / $range_magnitude; $range_up = ($range_norm_x * $observer_up_x) + ($range_norm_y * $observer_up_y) + ($range_norm_z * $observer_up_z); $range_east = ($range_norm_x * $observer_east_x) + ($range_norm_y * $observer_east_y); $range_north= ($range_norm_x * $observer_north_x)+ ($range_norm_y * $observer_north_y) + ($range_norm_z * $observer_north_z); // Calculating the Look Angles $obs_elevation = rad2deg(asin($range_up)); $obs_azimuth = rad2deg(atan2($range_east,$range_north)); if ( $obs_azimuth < 0 ) $obs_azimuth = 360 + $obs_azimuth; // Calculating the range according to the units if ($calc_range) { if ($range_units == 'Kilometres' ) $range_print = round (($range_magnitude * $round_trip),2); if ($range_units == 'milliseconds' ) $range_print = round ((($range_magnitude * $round_trip * 1000) / c) , 2) ; if ($range_units == 'symbols' ) $range_print = round ((($range_magnitude * $round_trip * 1000 * $symbol_rate) / c) , 2) ; } } //------------------------ Fill the results array for use later-----------------------------// $results [$i] = array ( 'Sat' => $sat_elements [$i]['Name'] , 'Epoch_age_s' => $delta_sec, 'sub_sat_long' => $sub_sat_long, 'Inclination' => $sat_elements [$i]['Inclination'], 'Azimuth' => $obs_azimuth, 'Elevation' => $obs_elevation, 'Range_km' => $range_magnitude ); $total_epoch_age = $total_epoch_age + $results [$i] ['Epoch_age_s']; } // Finalizing fclose ($tle_data); $average_age = round((($total_epoch_age / $no_of_sat) / 86400),2); $lista = $results; if ($sort_order == "Alphabetic") $lista = array_sort ($results, 'Sat'); if ($sort_order == "Longitude East to West") $lista = rarray_sort ($results, 'sub_sat_long'); if ($sort_order == "Longitude West to East") $lista = array_sort ($results, 'sub_sat_long'); // -- Save The Location in a cookie if ($use_cookie) { setcookie ("loc_cook", $observer_site, time()+60*60*24*90, "/"); setcookie ("lat_cook", $observer_lat, time()+60*60*24*90, "/"); setcookie ("lon_cook", $observer_long, time()+60*60*24*90, "/"); setcookie ("alt_cook", $observer_alt, time()+60*60*24*90, "/"); } //------------------------------------------------------------------------------------------// // Print the results inside an HTML table // //------------------------------------------------------------------------------------------// print_head(); print_table(); // -------------------------------- END of Table -----------------------------------------// // ------------------------------- Print "Functions" --------------------------------------// function print_head() // HTTP header is included here in order to set the cookie BEFORE. { print "<!DOCTYPE HTML PUBLIC '-//W3C//DTD HTML 4.01 Transitional//EN''http://www.w3.org/TR/html4/loose.dtd'>"; print "<HTML lang='en'><HEAD><META http-equiv='content-type' content='text/html; charset=iso-8859-1'> <TITLE>Sat Calc PHP</TITLE>"; if ($GLOBALS["bw"] == "TRUE") print "<LINK href='bw.css' rel='stylesheet' type='text/css'></HEAD><BODY>"; else print "<LINK href='style_sheet_1.css' rel='stylesheet' type='text/css'></HEAD><BODY>"; print ""; print "<H1>Clarke Belt Snapshot</H1><H3>Generated on <strong>"; print date("r"); print "</strong></h3>"; if ($GLOBALS["do_look_angle"] == "TRUE") {print "<H3>Look angles for {$GLOBALS["observer_site"]} ( "; if ($GLOBALS["observer_lat_sign"] == North) {printf ("%03.2f", $GLOBALS["observer_lat"]); print "° North, ";} if ($GLOBALS["observer_lat_sign"] == South) {printf ("%03.2f", -$GLOBALS["observer_lat"]); print "° South, ";} if ($GLOBALS["observer_long_sign"] == West) {printf ("%03.2f", -$GLOBALS["observer_long"]); print "° West, ";} if ($GLOBALS["observer_long_sign"] == East) {printf ("%03.2f", $GLOBALS["observer_long"]); print "° East, ";} print "Alt. {$GLOBALS["observer_alt"]} km. )</H3>"; } } function print_table_head () { Print "<br><table width='auto%' border='0' align='center' cellpadding='2' cellspacing='2'> <TR> <TD class='sath'>Satellite</TD><TD class='lonh'>Longitude</TD><TD class='lonh'>Inclination</TD>"; if ($GLOBALS["do_look_angle"]) { print "<TD class='azh'> Azimuth </TD> <TD class='azh'> Elevation </TD>"; if ($GLOBALS["calc_range"]) print "<TD class='ranh'> Range</TD>"; } print "</TR>"; } function print_end() { if ($GLOBALS["do_look_angle"]) print "<H3>Only satellites with elevation > 2° are shown</H3>"; print "<H3>{$GLOBALS["no_of_sat"]}"; print " Satellites in file <i>{$GLOBALS["tle_url"]} </i> - "; print "Average TLE Age: <b>{$GLOBALS["average_age"]}</b> days</H3><br>"; print "<TABLE width='100%' border='0' cellspacing='0' cellpadding='5'> <TR><TD align='left'><H2>file generated at <A href='http://www.golombek.com'>http://www.golombek.com</A></H2></TD> <TD align='right'><a href='http://validator.w3.org/check/referer'> <IMG src='images/html401.png' width='80' height='15' border='0' alt='valid HTML 4.1'></A> <A href='http://jigsaw.w3.org/css-validator/check/referer'> <IMG src='images/css.png' width='80' height='15' border='0' alt='valid CSS1'></A></TD> </TR></TABLE> "; // ------------------------------- Google AdSense --------------------------------------// // ------------------------------- Google Analytics --------------------------------------// print "<script type=\"text/javascript\"> var gaJsHost = ((\"https:\" == document.location.protocol) ? \"https://ssl.\" : \"http://www.\"); document.write(unescape(\"%3Cscript src='\" + gaJsHost + \"google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E\"));</script> <script type=\"text/javascript\"> try { var pageTracker = _gat._getTracker(\"UA-513682-1\"); pageTracker._trackPageview(); } catch(err) {} </script>"; print "</BODY></HTML>"; } //////////////////////////////////////////////////////////////////////////////////////////////// function print_table() { print_table_head (); $lcl_res_arr = $GLOBALS["lista"]; $do_look_angle = $_GET ['calc_ang']; $calc_range = $_GET ['calc_range']; $range_units = $_GET ['range_units']; $symbol_rate = $_GET ['sym_rate']; if ($_GET ['round_trip'] == "TRUE") $round_trip = 2; else $round_trip = 1; for ($i=0; $i<($GLOBALS["no_of_sat"] - 1); $i++) { $sub_sat_long = $lcl_res_arr[$i]['sub_sat_long']; $obs_elevation = $lcl_res_arr[$i]['Elevation']; $obs_azimuth = $lcl_res_arr[$i]['Azimuth']; $range_magnitude = $lcl_res_arr[$i]['Range_km']; if (($obs_elevation > 1.5) || (!$do_look_angle)) { print "<tr><TD class='sat'>"; print "{$lcl_res_arr [$i]['Sat']}</TD>"; print "<TD class='lon'>"; if ($sub_sat_long >= 0) {printf ("%03.2f", $sub_sat_long); print "° East";} if ($sub_sat_long < 0) {printf ("%03.2f", -$sub_sat_long); print "° West";} print "</td>"; if ( $lcl_res_arr [$i]['Inclination'] > 2 ) print "<TD class='incl'>"; if ( $lcl_res_arr [$i]['Inclination'] <= 2 ) print "<TD class='lon'>"; printf ("%1.3f", $lcl_res_arr [$i]['Inclination']); print "°</td>"; if ($do_look_angle) // Prints the Look angles { print "<TD class='az'>"; printf ("%03.2f", $obs_azimuth); print "°</td>"; print "<TD class='el'>"; printf ("%02.2f", $obs_elevation); print "°</td>"; if ($calc_range) // Print the Range { if ($range_units == 'Kilometers' ) $range_print = round (( $range_magnitude * $round_trip),2); if ($range_units == 'milliseconds' ) $range_print = round ((($range_magnitude * $round_trip * 1000) / c) , 2) ; if ($range_units == 'symbols' ) $range_print = round ((($range_magnitude * $round_trip * 1000 * $symbol_rate) / c) , 2) ; print "<TD class='ran'>"; printf ("%.2f", $range_print); if ( $range_units == 'Kilometers' ) print" km</TD>"; if ($range_units == 'milliseconds' ) print" ms</TD>";; if ($range_units == 'symbols' ) print" sym</TD>"; } } print "</tr>"; } } print "</table>"; print_end(); } function nofile($file) { print "<TITLE>File Error</TITLE> <LINK href='style_sheet_1.css' rel='stylesheet' type='text/css'></HEAD><BODY>"; print "<H1>Sorry, an error has been encountered</H1><br>"; print "The TLE file at <a href=$file>$file<a> could not be opened, it appears that it doesn't exist. Check that the URL is correct.<BR><BR>"; print "<DIV align='center'><IMG SRC='error404.png'></DIV>"; print "</BODY></HTML>";} function array_sort($array, $key) { for ($i = 0; $i < sizeof($array); $i++) { $sort_values[$i] = $array[$i][$key]; } asort ($sort_values); reset ($sort_values); while (list ($arr_key, $arr_val) = each ($sort_values)) { $sorted_arr[] = $array[$arr_key]; } return $sorted_arr; } function rarray_sort($array, $key) { for ($i = 0; $i < sizeof($array); $i++) { $sort_values[$i] = $array[$i][$key]; } arsort ($sort_values); reset ($sort_values); while (list ($arr_key, $arr_val) = each ($sort_values)) { $sorted_arr[] = $array[$arr_key]; } return $sorted_arr; } ?>