<?php
/*
###########################################################################
Voyagers 1 and 2 Hourly Ephemerides
This program computes the hour-by-hour geocentric and heliocentric
statistics of Voyagers 1 and 2 for any given hour since their
launch dates.
This way, you can study the historical progress of both Voyagers
over the years and even make projections into the future.
########################################################
ONE LIGHT DAY PROJECTIONS UTC VIA NASA/JPL HORIZONS API:
Voyager 1 = 1 Light Day From Earth Date: 2026-Nov-19-Thu
Voyager 2 = 1 Light Day From Earth Date: 2035-Nov-01-Thu
------------------------------------------------------------
Voyager 1 = 1 Light Day From Sun Date: 2027-Feb-04-Thu
Voyager 2 = 1 Light Day From Sun Date: 2035-Nov-28-Wed
------------------------
SOME BASIC APPLIED DATA:
* 1 AU = 149,597,870.7 km = 92,955,807.3 mi
* Speed of Light = 299,792.458 km/s = 186,282.397 mi/s
1 Light Day = 25,902,068,371.2 km = 16,094,799,105.2 mi
* 1 statute mile = 1.609344 km
* (asterisk) Means an EXACT DEFINITION
AUTHOR : Jay Tanner - 2026
LANGUAGE : PHP v8.2.12
LICENSE : Public Domain
###########################################################################
*/
ob_start(); // Oy!
// ---------------------------------------------------------------
// Define the program cookie name and set it to expire in 30 days.
$CookieName = 'Voyagers-1-and-2-Hourly-Ephemerides';
$SetToExpireIn30Days = time() + 30*86400;
// ------------------------------------------------------------------
// Define JavaScript message to display in (TextArea1) while working.
$_COMPUTING_ = "TextArea1.innerHTML=' W O R K I N G --- This may take a few moments.';";
// ---------------------------------
// Define PHP program and HTML info.
$_AUTHOR_ = 'Jay Tanner of Geneva, NY, USA';
$_PROGRAM_VERSION_ = 'v1.00 - '; $at = "at Local Time "; $LTC = "UTC";
$_SCRIPT_FILE_PATH_ = Filter_Input(INPUT_SERVER, 'SCRIPT_FILENAME');
$_REVISION_DATE_ = $_PROGRAM_VERSION_ .'Revised: '. date("Y-F-d-l $at h:i:s A ($LTC", FileMTime($_SCRIPT_FILE_PATH_))."−05:00)";
$_BROWSER_TAB_TEXT_ = "Voyagers 1 and 2 Hourly Ephemerides";
$_INTERFACE_TITLE_ = "<span style='font-size:15pt;'>Voyagers 1 and 2 Hourly Ephemerides</span><br><span style='font-size:12pt;'>Built Around The NASA/JPL Horizons API</span><br><br><span style='font-size:10pt;'>PHP Program by $_AUTHOR_</span>";
/* -------------------------------------
Define main TextArea text and background
colors and HTML table row span. If an
error is reported, then these colors
will change internally to red/white.
*/
$TxColor = 'black';
$BgColor = 'white';
/* ----------------------------------------
Define 3-letter month name abbreviations
for use with calendar computations.
*/
define('MONTHS', 'JanFebMarAprMayJunJulAugSepOctNovDec');
/* ------------------------------------------
Define 3-letter weekday name abbreviations
for use with calendar computations.
*/
define('DOWs', 'SunMonTueWedThuFriSat');
// ------------------------------------------------
// Do this only if [SUBMIT] button was NOT clicked.
$w = Filter_Input(INPUT_POST, 'SubmitButton');
if (!IsSet($w))
{
/* ----------------------------------------------------------------------
If this program is being called externally, rather than being executed
by clicking the [SUBMIT] button, and an active cookie also exists,
then restore the previously saved interface settings from it. If
the user leaves and comes back later, all the interface settings
will be remembered and restored if the cookie was not deleted.
Otherwise, the user would have to re-enter every parameter from
scratch for each and every computation because they would all be
forgotten after each usage.
*/
$w = Filter_Input(INPUT_COOKIE, $CookieName);
if (IsSet($w))
{
$CookieDataString = Filter_Input(INPUT_COOKIE, $CookieName);
list ($Year, $Month, $Day)
= Preg_Split("[\|]", $CookieDataString);
}
else
/* -----------------------------------------------------------
If there is no previous cookie with the interface settings,
then set the initial default interface startup values and
store them in a new cookie.
*/
{
$Year = GMDate('Y');
$Month = GMDate('M');
$Day = GMDate('d');
// -------------------------------------------
// Store current interface settings in cookie.
$CookieDataString = "$Year|$Month|$Day";
SetCookie ($CookieName, $CookieDataString, $SetToExpireIn30Days);
} // End of else {...}
} // End of if (!isset(...))
// ------------------------------------------
// Read values of all interface arguments and
// set any empty arguments to default values.
$w = Filter_Input(INPUT_POST, 'SubmitButton');
if (isset($w))
{
$Year = trim(Filter_Input(INPUT_POST, 'Year'));
if (!Is_Numeric($Year)) {$Year = GMDate('Y');}
$Year = SPrintF("%4d", $Year);
/* -------------------------------------------
Get START month as a number (1 to 12) or as
a 3-letter abbreviation ('Jan' to 'Dec').
NOT case-sensitive.
*/
$Month = UCFirst(substr(StrToLower(trim(Filter_Input(INPUT_POST, 'Month'))),0,3));
if ($Month == '') {$Month = GMDate('M');}
if (Is_Numeric($Month) and $Month == 0) {$Month = GMDate("M");}
for ($ii=0; $ii < 1; $ii++)
{
if (Is_Numeric($Month))
{
$m = IntVal($Month);
if ($m < 0 or $m > 12) {$Month = GMDate("M"); break;}
$Month = substr(MONTHS, 3*($m-1), 3);
}
$jj = StrPos(MONTHS, $Month);
if ($jj === FALSE) {$Month = GMDate("M"); break;}
$Month = substr(MONTHS, $jj, 3);
}
$Day = trim(Filter_Input(INPUT_POST, 'Day'));
if ($Day == '') {$Day = IntVal(GMDate('d'));}
$Day = SPrintF("%02d", $Day);
// -------------------------------------
// Store interface argument in a cookie.
$CookieDataString = "$Year|$Month|$Day";
SetCookie ($CookieName, $CookieDataString, $SetToExpireIn30Days);
}
/* -----------------------------------------------------------
Put code here to optionally check individual arguments for
validity in reverse input order. If errors found, then set
error flag and message values accordingly.
NOTE: Horizons will catch some errors, such as invalid date
errors.
*/
$ErrorReported = FALSE;
$ErrMssg = '';
// -----------------------------
// Set initial uniform width for
// tables alignment in pixels.
$TableWidth = '680';
// -------------------------------------------
// If error was reported (TRUE), then display
// the error message on a red background.
if ($ErrorReported)
{
$TxColor = 'white';
$BgColor = '#CC0000';
$TextArea2Text = '';
$TextArea1Text =
"=== ERROR ===
$ErrMssg";
}
else
{
// ------------------------------------------------------
// Construct full date and time strings for Horizons API.
$StartDateTime = "$Year-$Month-$Day 00:00:00 UT";
$StopDateTime = "$Year-$Month-$Day 23:59:59";
// ---------------------
// Define table headers.
$OutputTextHeaderG = "\nCALENDAR_DATE_UTC | DISTANCE_AU | RAD_VEL_mi/h | LIGHT_TIME\n------------------|-------------|--------------|----------------";
$OutputTextHeaderH = "\nCALENDAR_DATE_UTC | DISTANCE_AU | RAD_VEL_mi/h | LIGHT_TIME\n------------------|-------------|--------------|----------------";
// ------------------------------------------------------------------------------
// Compute the geocentric and heliocentric ephemeris statistics for the Voyagers.
$V1G = Voyager_G ('Voyager 1', $StartDateTime, $StopDateTime, $OutputTextHeaderG);
$V2G = Voyager_G ('Voyager 2', $StartDateTime, $StopDateTime, $OutputTextHeaderG);
$V1H = Voyager_H ('Voyager 1', $StartDateTime, $StopDateTime, $OutputTextHeaderH);
$V2H = Voyager_H ('Voyager 2', $StartDateTime, $StopDateTime, $OutputTextHeaderH);
// -------------------------------------------
// Modify certain error messages, if detected.
$BadDateErr = "Cannot interpret date.";
$BadDateStr = "ERROR: Check the given calendar date.\nThe date $Year-$Month-$Day is not a valid date on the real calendar.\n";
$SpanErr = "No ephemeris for target";
$SpanStr = "No ephemeris is available for the given date.";
if (StrPos($V1G, $BadDateErr) !== FALSE)
{$OutputTextHeaderG = ''; $V1G = $BadDateStr;}
if (StrPos($V2G, $BadDateErr) !== FALSE)
{$OutputTextHeaderG = ''; $V2G = $BadDateStr;}
if (StrPos($V1H, $BadDateErr) !== FALSE)
{$OutputTextHeaderH = ''; $V1H = $BadDateStr;}
if (StrPos($V2H, $BadDateErr) !== FALSE)
{$OutputTextHeaderH = ''; $V2H = $BadDateStr;}
if (StrPos($V1G, $SpanErr) !== FALSE) {$OutputTextHeaderG = '';}
if (StrPos($V2G, $SpanErr) !== FALSE) {$OutputTextHeaderG = '';}
if (StrPos($V1H, $SpanErr) !== FALSE) {$OutputTextHeaderH = '';}
if (StrPos($V2H, $SpanErr) !== FALSE) {$OutputTextHeaderH = '';}
$V1G = trim(Str_Replace('prior to ', "prior to\n", $V1G));
$V2G = Str_Replace('prior to ', "prior to\n", $V2G);
$V1H = Str_Replace('prior to ', "prior to\n", $V1H);
$V2H = Str_Replace('prior to ', "prior to\n", $V2H);
$V1G = trim(Str_Replace('after ', "after\n", $V1G));
$V2G = Str_Replace('after ', "after\n", $V2G);
$V1H = Str_Replace('after ', "after\n", $V1H);
$V2H = Str_Replace('after ', "after\n", $V2H);
// *********************************************************
// CONSTRUCT OUTPUT TEXT BLOCKS BASED ON COMPUTATIONS ABOVE.
// *********************************************************
$TextArea1Text =
" VOYAGERS 1 and 2 HOURLY EPHEMERIS
FROM BOTH GEOCENTRIC and HELIOCENTRIC PERSPECTIVES
################################################################
VOYAGER 1: GEOCENTRIC statistics for each hour of $Year-$Month-$Day
$OutputTextHeaderG
$V1G
----------------------------------------------------------------
VOYAGER 2: GEOCENTRIC statistics for each hour of $Year-$Month-$Day
$OutputTextHeaderG
$V2G
################################################################
################################################################
HELIOCENTRIC
VOYAGER 1: HELIOCENTRIC statistics for each hour of $Year-$Month-$Day
$OutputTextHeaderH
$V1H
----------------------------------------------------------------
VOYAGER 2: HELIOCENTRIC statistics for each hour of $Year-$Month-$Day
$OutputTextHeaderH
$V2H
";
}
// ****************************
// Define TextArea2 text block.
$TextArea2Text =
" GENERAL PROGRAM INFO
Computations via the NASA/JPL Horizons API
This program computes both the geocentric and heliocentric statistics for
Voyager 1 and Voyager 2 for any date since the date of their launches.
It can be used to compute their historical positional statistics since the
date of launch to the current date and can also be used to find the projected
dates when the two Voyagers reach a given distance from both the Earth and the
Sun, such as when they will be one light day distant from them.
##############################################################################
SOME BASIC APPLIED DATA:
* 1 AU = 149,597,870.7 km = 92,955,807.3 mi
* Speed of Light = 299,792.458 km/s = 186,282.397 mi/s
1 Light Day = 25,902,068,371.2 km = 16,094,799,105.2 mi
* 1 statute mile = 1.609344 km
* (asterisk) Means an EXACT DEFINITION
##############################################################################
COLUMNS DATA
------------
DISTANCE_AU : Distance in Astronomical Units from Earth/Sun
RAD_VEL_mi/h : Radial velocity in mi/h. -Neg = Approaching; +Pos = Receding
This is the speed at which the spacecraft is approaching or re-
ceding from the Earth or Sun.
SPECIAL NOTE : When the Earth in its orbit is traveling in the same direction
as an outgoing Voyager, the radial velocity is a negative value which means
it is approaching the Earth, rather than receding. This is an illusion caused
by the fact that the Earth, at a certain point in its orbit, is moving faster
than the Voyager is receding away from us in the same general direction.
LIGHT_TIME : Light or signal time from Spacecraft to observation point.
";
/* --------------------------------------------------------------------------
Determine number of text columns and rows to use in the output text areas.
These values vary randomly according to the text block width and length.
The idea is to eliminate the need for scroll-bars within the text areas
or worry as much about the variable dimensions of a text display area.
*/
// --------------------------------------------
// Text Area 1 - Default = At least 80 columns.
$Text1Cols = 1 + Max(Array_Map('StrLen', PReg_Split("[\n]", trim($TextArea1Text))));
if ($Text1Cols < 180) {$Text1Cols = 67;} // Default
$Text1Rows = 2 + Substr_Count($TextArea1Text, "\n");
// --------------------------------------------
// Text Area 2 - Default = At least 80 columns.
$Text2Cols = 1 + Max(Array_Map('StrLen', PReg_Split("[\n]", trim($TextArea2Text))));
if ($Text2Cols < 80) {$Text2Cols = 80;} // Default
$Text2Rows = 2 + Substr_Count($TextArea2Text, "\n");
// ******************************************
// GENERATE CLIENT WEB PAGE TO DISPLAY OUTPUT
print <<< _HTML
<!DOCTYPE HTML>
<HTML>
<head>
<title>$_BROWSER_TAB_TEXT_</title>
<meta name='viewport' content='width=device-width, initial-scale=0.8'>
<meta http-equiv='content-type' content='text/html; chrset=UTF-8'>
<meta http-equiv='pragma' content='no-cache'>
<meta http-equiv='expires' content='-1'>
<meta name='description' content='Voyagers 1 and 2 Statistics For Any Date'>
<meta name='keywords' content='NeoProgrammics / PHP Science Labs'>
<meta name='author' content='Jay Tanner - https://www.NeoProgrammics.com'>
<meta name='robots' content='index,follow'>
<meta name='googlebot' content='index,follow'>
<style>
BODY {color:white; background:black; font-family:Verdana; font-size:12pt; line-height:125%;}
TABLE
{font-size:13pt; border: 1px solid black;}
TD
{
color:black; background:white; line-height:150%; font-size:10pt;
padding:6px; text-align:center;
}
UL
{font-family:Verdana; font-size:12pt; line-height:150%; text-align:justify;}
PRE
{
background:white; color:black; font-family:monospace; font-size:12.5pt;
font-weight:bold; text-align:left; line-height:125%; padding:6px;
border:2px solid black; border-radius:8px;
page-break-before:page;
}
DIV
{
background:white; color:black; font-family:Verdana; font-size:11pt;
font-weight:normal; line-height:125%; padding:6px;
}
TEXTAREA
{
background:white; color:black; font-family:monospace; font-size:12pt;
font-weight:bold; padding:4pt; white-space:pre; border-radius:8px;
line-height:125%;
}
INPUT[type='text']::-ms-clear {width:0; height:0;}
INPUT[type='text']
{
font-family:monospace; color:black; background:white; font-size:12pt;
font-weight:bold; text-align:center; box-shadow:2px 2px 3px #666666;
border:2px solid black; border-radius:4px;
}
INPUT[type='text']:focus
{
font-family:monospace; background:white; box-shadow:2px 2px 3px #666666;
font-size:12pt; border:2px solid blue; text-align:center; font-weight:bold;
border-radius:4px;
}
INPUT[type='submit']
{
background:black; color:cyan; font-family:Verdana; font-size:10pt;
font-weight:bold; border-radius:4px; border:4px solid #777777;
padding:3pt;
}
INPUT[type='submit']:hover
{
background:black; color:white; font-family:Verdana; font-size:10pt;
font-weight:bold; border-radius:4px; border:4px solid red;
padding:3pt;
}
// Link states MUST be set in the following order:
// :link, :visited, :hover, :active
A:link
{
font-size:10pt; background:transparent; color:#8080FF; border-radius:4px;
font-family:Verdana; font-weight:bold; text-decoration:none;
line-height:175%; padding:3px; border:1px solid transparent;
}
A:visited
{
font-size:10pt; background:transparent; color:DarkCyan; border-radius:4px;
}
A:hover
{
font-size:10pt; background:yellow; color:black; border:1px solid black;
box-shadow:1px 1px 3px #222222; border-radius:4px;
}
A:active
{
font-size:10pt; background:yellow; color:black; border-radius:4px;
}
HR {background:red; height:4px; border:0px;}
[title-text]:hover:after
{
opacity:1.0;
transition:all 1.0s ease 1.0s;
text-align:left;
visibility:visible;
}
[title-text]:after
{
opacity:1.0;
content:attr(title-text);
text-align:left;
left:50%;
background-color:yellow;
color:black;
font-size:10pt;
position:absolute;
padding:1px 5px 2px 5px;
white-space:pre;
border:1px solid red;
z-index:1;
visibility:hidden;
}
[title-text] {position: relative;}
::selection{background-color:yellow !important; color:black !important;}
::-moz-selection{background-color:yellow !important; color:black !important;}
</style>
</head>
<body>
<!-- Define container form --->
<form name="form1" method="post" action="">
<!-- Define main page title/header. --->
<table width="$TableWidth" align="center" border="0" cellspacing="1" cellpadding="3">
<tr><td colspan="99" style="color:white; background-color:#000066; border:2px solid white; border-radius:8px 8px 0px 0px;">$_INTERFACE_TITLE_</td></tr>
</table>
<!-- Define calendar date text box --->
<table width="$TableWidth" align="center" border="0" cellspacing="1" cellpadding="3">
<tr>
<td style='background:LightYellow; line-height:150%;'><b>Calendar Date</b><br>yyyy Mmm dd<br><input name="Year" type="text" value="$Year" size="6" maxlength="5"><input name="Month" type="text" value="$Month" size="4" maxlength="3"><input name="Day" type="text" value="$Day" size="3" maxlength="2"></td>
</tr>
</table>
<!-- Top yellow source code view link. --->
<br>
<table width="$TableWidth" align="center" cellspacing="1" cellpadding="3">
<tr>
<td colspan="1" style='font-size:10pt; color:black; background:black;
text-align:center;' title=' Tries to Open in a New Tab. '>
<b><a href="View-Source-Code.php" target="_blank"
style='font-family:Verdana; color:black; background:yellow;
text-decoration:none; border:1px solid black; padding:4px;
border-radius:4px; font-weight:normal;'>
View/Copy Source Code </a></b>
</td>
</tr>
</table>
<!-- Define [SUBMIT] button --->
<table width="$TableWidth" align="center" border="0" cellspacing="1" cellpadding="3">
<tr><td colspan="99" style="background-color:black;"><input type="submit" name="SubmitButton" value=" S U B M I T " OnClick="$_COMPUTING_"
></td></tr>
</table>
<!-- Define TextArea1 --->
<table width="$TableWidth" align="center" border="0" cellspacing="1" cellpadding="3">
<tr>
<td colspan="99" style="text-align:center; color:GreenYellow; background-color:black;">Double-Click Within Text Area to Select ALL Text<br>
<textarea ID="TextArea1" name="TextArea1" style="color:$TxColor; background:$BgColor; padding:6px; border:2px solid white;" cols="$Text1Cols" rows="$Text1Rows" ReadOnly OnDblClick="this.select();" OnMouseUp="return true;">
$TextArea1Text
</textarea>
</td>
</tr>
</table>
<!-- Define TextArea2 --->
<table width="$TableWidth" align="center" border="0" cellspacing="1" cellpadding="3">
<tr>
<td colspan="99" style="text-align:center; color:GreenYellow; background:black;">Double-Click Within Text Area to Select ALL Text<br>
<textarea ID="TextArea2" name="TextArea2" style="color:black; background:white; padding:6px;" cols="$Text2Cols" rows="$Text2Rows" ReadOnly OnDblClick="this.select();" OnMouseUp="return true;">
$TextArea2Text
</textarea>
</tr>
</table>
<!-- Define page footer --->
<table width="$TableWidth" align="center" border="0" cellspacing="1" cellpadding="3">
<tr>
<td colspan="99" style="color:GreenYellow; background:black;">PHP Program by $_AUTHOR_<br><span style="color:silver; background:black;">$_REVISION_DATE_</span></td>
</tr>
</table>
</form>
<!-- End of container form --->
<!-- Extra bottom scroll space --->
<br><br><br><br><br><br><br><br><br><br><br><br>
<br><br><br><br><br><br><br><br><br><br><br><br>
</body>
</HTML>
_HTML;
/*
###########################################################################
This function returns the decimal hours equivalent to the given HMS string.
Generic. No special error checking is done.
NO DEPENDENCIES
###########################################################################
*/
function HMS_to_Hours ($HMSString, $Decimals=16)
{
$HHmmss = trim($HMSString);
$decimals = trim($Decimals);
/* ------------------------------------------------
Account for and preserve any numerical +/- sign.
Internal work will use absolute values and any
numerical sign will be reattached the output.
*/
$NumSign = substr($HHmmss,0,1);
if ($NumSign == '-')
{$HHmmss = substr($HHmmss,1,StrLen($HHmmss));}
else
{
if ($NumSign == '+')
{$HHmmss = substr($HHmmss,1,StrLen($HHmmss));}
$NumSign = '+';
}
// ------------------------------------------------------------------
// Replace any colons : with blank spaces and remove any white space.
$HHmmss = PReg_Replace("/\s+/", " ", Str_Replace(":", " ", $HHmmss));
// ----------------------------------------
// Count the HMS time elements from 1 to 3.
$n = 1 + Substr_Count($HHmmss, ' ');
$hh = $mm = $ss = 0;
/* ----------------------------------------------------------------------
Collect all given time element values. They can be integer or decimal
values. Only counts up to three HMS values and any values beyond those
are simply ignored.
*/
for ($i=0; $i < 1; $i++)
{
if ($n == 1){list($hh) = PReg_Split("[ ]", $HHmmss);}
if ($n == 2){list($hh,$mm) = PReg_Split("[ ]", $HHmmss);}
if ($n == 3){list($hh,$mm,$ss) = PReg_Split("[ ]", $HHmmss);}
}
// ------------------------------------------------------------------------
// Compute HMS equivalent in decimal hours to the given number of decimals.
return $NumSign.(round((3600*$hh + 60*$mm + $ss)/3600,$decimals));
} // End of HMS_to_Hours(...)
/*
###########################################################################
This function returns an HMS string equivalent to an hours argument rounded
to the specified number of decimals.
Generic. No special error checking is done.
NO DEPENDENCIES
###########################################################################
*/
function Hours_to_HMS ($Hours, $Decimals=0)
{
$hours = trim($Hours); $NumSign = ($hours < 0)? '-':'';
$hours = Str_Replace('+', '', Str_Replace('-', '', $hours));
// ---------------------
// Set working decimals.
$Q = 32;
$decimals = floor(abs(trim($Decimals)));
$decimals = ($decimals > $Q)? $Q : $decimals;
$decimals = ($decimals < 0)? 0 : $decimals;
// ------------------------------------
// Compute hours,minutes and seconds to
// the specified number of decimals.
$hh = bcAdd($hours, '0');
$min = bcMul('60', bcSub($hours, $hh, $Q),$Q);
$mm = bcAdd($min, '0');
$sec = bcMul('60', bcSub($min, $mm, $Q),$Q);
$ss = SPrintF("%1.$decimals"."f", $sec);
if ($ss < 10){$ss = "0$ss";}
// -------------------------------------------
// Try to account for that blasted 60s glitch.
if ($ss == 60) {$mm += 1; $ss = 0;}
if ($mm == 60) {$hh += 1; $mm = 0;}
// ------------------------------------------
// Construct and return time elements string.
$hh = SPrintF("%02d", $hh);
$mm = SPrintF("%02d", $mm);
$ss = SPrintf("%1.$decimals"."f", $ss);
if ($ss < 10){$ss = "0$ss";}
return "$NumSign$hh:$mm:$ss";
} // End of Hours_to_HMS (...)
/*
###########################################################################
This function returns a simple apparent geocentric Voyager spacecraft
positional ephemeris from the NASA/JPL Horizons API.
If no ephemeris is returned, then the text from the API is returned as-is
because it could be an error message or some other status or query text.
NO DEPENDENCIES
###########################################################################
*/
function Voyager_G ($TargObjID,$StartDateTime,$StopDateTime)
{
// ===========================================================================
// Construct query URL for the NASA/JPL Horizons API.
$TargObjID = trim($TargObjID);
$Command = URLEncode($TargObjID);
// --------------------
// Construct API query.
$From_Horizons_API =
"https://ssd.jpl.nasa.gov/api/horizons.api?format=text" .
"&COMMAND='$Command'" .
"&OBJ_DATA='NO'" .
"&MAKE_EPHEM='YES'" .
"&EPHEM_TYPE='OBSERVER'" .
"&CAL_FORMAT='CAL'" .
"&REF_SYSTEM='ICRF'" .
"&RANGE_UNITS='AU'" .
"&SUPPRESS_RANGE_RATE='NO'" .
"&ANG_FORMAT='HMS'" .
"&APPARENT='AIRLESS'" .
"&CENTER='500@399'" .
"&TIME_DIGITS='MINUTES'" .
"&TIME_ZONE='+00:00'" .
"&START_TIME='$StartDateTime'" .
"&STOP_TIME='$StopDateTime'" .
"&STEP_SIZE='1 hour'" .
"&EXTRA_PREC='NO'" .
"&CSV_FORMAT='YES'" .
"&QUANTITIES='2,20,21'" ;
// ===========================================
/* ---------------------------------------------------------------------
This function returns a simple apparent geocentric Voyager spacecraft
ephemeris statistics from the NASA/JPL Horizons API.
*/
$EphemTable = Str_Replace(",\n", " \n", File_Get_Contents($From_Horizons_API));
/* --------------------------------------------------------
If no ephemeris is found, then return the text from the
API as-is. It may be an error message or some other text.
*/
if (StrPos($EphemTable, '$$SOE') === FALSE) {return HTMLEntities($EphemTable);}
/* -----------------------------------------------------
Set pointers to start and end of CSV ephemeris table.
A value of FALSE means no ephemeris was found within
the given source text.
*/
$i = StrPos($EphemTable, '$$SOE');
$j = StrPos($EphemTable, '$$EOE');
/* ------------------------------------------------
Extract ONLY the existing ephemeris data line(s)
from between the pointers.
*/
$EphemTable = ' ' . trim((substr($EphemTable, $i+5, $j-$i-5)));
// -----------------------------------
// And then, parse the table contents.
$EphemTable = Parse_Geocentric_Table ($EphemTable);
// Done
return HTMLEntities($EphemTable);
} // END OF Voyager_G (...)
/*
###########################################################################
This function returns a simple apparent heliocentric Voyager spacecraft
ephemeris statistics from the NASA/JPL Horizons API.
If no ephemeris is returned, then the text from the API is returned as-is
because it could be an error message or some other status or query text.
NO DEPENDENCIES
###########################################################################
*/
function Voyager_H ($TargObjID,$StartDateTime,$StopDateTime)
{
// ===========================================================================
// Construct query URL for the NASA/JPL Horizons API.
$TargObjID = trim($TargObjID);
$Command = URLEncode($TargObjID);
// --------------------
// Construct API query.
$From_Horizons_API =
"https://ssd.jpl.nasa.gov/api/horizons.api?format=text" .
"&COMMAND='$Command'" .
"&OBJ_DATA='NO'" .
"&MAKE_EPHEM='YES'" .
"&EPHEM_TYPE='OBSERVER'" .
"&CAL_FORMAT='CAL'" .
"&REF_SYSTEM='ICRF'" .
"&RANGE_UNITS='AU'" .
"&SUPPRESS_RANGE_RATE='NO'" .
"&ANG_FORMAT='HMS'" .
"&APPARENT='AIRLESS'" .
"&CENTER='500@10'" .
"&TIME_DIGITS='MINUTES'" .
"&TIME_ZONE='+00:00'" .
"&START_TIME='$StartDateTime'" .
"&STOP_TIME='$StopDateTime'" .
"&STEP_SIZE='1 hour'" .
"&EXTRA_PREC='NO'" .
"&CSV_FORMAT='YES'" .
"&QUANTITIES='2,20,21'" ;
/* ------------------------------------------------------------------------
Send query to Horizons API to obtain the apparent heliocentric ephemeris
statistics for the given body ID as a plain-text CSV ephemeris table.
*/
$EphemTable = Str_Replace(",\n", " \n", File_Get_Contents($From_Horizons_API));
/* --------------------------------------------------------
If no ephemeris is found, then return the text from the
API as-is. It may be an error message or some other text.
*/
if (StrPos($EphemTable, '$$SOE') === FALSE)
{
return HTMLEntities($EphemTable);
}
/* -----------------------------------------------------
Set pointers to start and end of CSV ephemeris table.
A value of FALSE means no ephemeris was found within
the given source text.
*/
$i = StrPos($EphemTable, '$$SOE');
$j = StrPos($EphemTable, '$$EOE');
/* ------------------------------------------------
Extract ONLY the existing ephemeris data line(s)
from between the pointers.
*/
$EphemTable = ' ' . trim((substr($EphemTable, $i+5, $j-$i-5)));
// -----------------------------------
// And then, parse the table contents.
$EphemTable = Parse_Heliocentric_Table ($EphemTable);
// Done.
return HTMLEntities($EphemTable);
} // END OF Voyager_H (...)
/*
This function parses and reformats the geocentric
ephemeris data for display.
*/
function Parse_Geocentric_Table ($GeoTableTxt)
{
$T = trim($GeoTableTxt);
$wArray = PReg_Split("[\n]", $T);
$wCount = count($wArray);
$out = '';
for ($i=0; $i < $wCount; $i++)
{
$CurrLine = trim($wArray[$i]);
list (
$DateTimeStr,
$w, $w,
$RA, $Decl, $Delta, $DelDot,
$LightTime
) = Preg_Split("[,]", $CurrLine);
$RA = trim($RA);
$Decl = trim($Decl);
$Delta = SPrintF("% 11.7f", trim($Delta));
$DelDot = SPrintF("% +11.3f", trim($DelDot)*3600/1.609344);
$LightTime = Hours_to_HMS(trim($LightTime/60), 2);
$xLightTime = LightTime_HMS_to_LightTime_DHMS ($LightTime);
$out .= "$DateTimeStr | $Delta | $DelDot | $xLightTime\n";
}
return $out;
} // END OF Parse_Geocentric_Table (...)
/*
This function parses and reformats the heliocentric
ephemeris data for display.
*/
function Parse_Heliocentric_Table ($HelioTableTxt)
{
$T = trim($HelioTableTxt);
$wArray = PReg_Split("[\n]", $T);
$wCount = count($wArray);
$out = '';
for ($i=0; $i < $wCount; $i++)
{
$CurrLine = trim($wArray[$i]);
list (
$DateTimeStr,
$w, $w,
$RA, $Decl, $Delta, $DelDot,
$LightTime
) = Preg_Split("[,]", $CurrLine);
$Delta = SPrintF("%11.7f", trim($Delta));
$DelDot = SPrintF("% +11.3f", trim($DelDot)*3600/1.609344);
$LightTime = Hours_to_HMS(trim($LightTime/60), 2);
$xLightTime = LightTime_HMS_to_LightTime_DHMS ($LightTime);
$out .= "$DateTimeStr | $Delta | $DelDot | $xLightTime\n";
}
return $out;
} // END OF Parse_Heliocentric_Table (...)
// ---------------------------------------------------------
// Utility function to add days to light time, if necessary.
function LightTime_HMS_to_LightTime_DHMS ($LightTimeHMS)
{
$HMS = trim($LightTimeHMS);
if (IntVal($HMS) < 24) {return "0d $HMS";}
list ($HH,$mm,$ss) = PReg_Split("[:]", $HMS);
$days = IntVal($HH / 24);
$hh = SPrintF("%02d", IntVal($HH) - 24);
while ($hh > 24) {$hh = SPrintF("%02d", IntVal($hh) - 24);}
return "$days" . "d $hh:$mm:$ss";
}
// END OF PROGRAM
?>