Overview  Package   Class  Use  Tree  Deprecated  Index  Help 
 PREV CLASS   NEXT CLASS FRAMES    NO FRAMES    
SUMMARY: NESTED | FIELD | CONSTR | METHOD DETAIL: FIELD | CONSTR | METHOD

astro
Class Broker

java.lang.Object
  extended by astro.Broker

public class Broker
extends Object

A stand-alone code excerpt for static telescope brokerage. This class allows decision of targets being observable at a given location. At the date in question, this includes that

The accuracy of the alogirthm is not too high and is estimated to give the sun's position down to a quarter of a degree around the year of 2000.

Nested Class Summary
static class Broker.Height
          Test the height of an astronomical object.
static class Broker.Sol
          Test the solar height.
 
Field Summary
private static double A1EQC
          The constant coefficient in equation of center of the sun.
private static double A2EQC
          The constant coefficient in equation of center of the sun.
private static double A3EQC
          The linear coefficient in equation of center of the sun.
private static double ALAM
          The constant coefficient in apparent longitude.
private static double AM
          The constant coefficient in geometric mean longitude.
private static double ANU
          Constant coefficient for calculating mean perihelium.
private static double ANULL
          The constant coefficient in geometric mean anomaly.
private static double ASUN
          The constant coefficient, ecliptic obliquity.
private static double B1EQC
          The linear coefficient in equation of center of the sun.
private static double B2EQC
          The linear coefficient in equation of center of the sun.
private static double BLAM
          The linear coefficient in apparent longitude.
private static double BM
          The linear coefficient in geometric mean longitude.
private static double BNU
          Linear coefficient for calculating mean perihelium.
private static double BNULL
          The linear coefficient in geometric mean anomaly.
private static double BSUN
          The linear coefficient, ecliptic obliquity.
private static double C1EQC
          The quadratic coefficient in equation of center of the sun.
private static double CM
          The quadratic coefficient in geometric mean longitude.
private static double CNULL
          The quadratic coefficient in geometric mean anomaly.
private static double[] CONST
          Constants required for the siderael time algorithm.
static double DEFAULTHEIGHT
          Default minimum object height.
static double DEFAULTSOL
          Default maximum solar height.
private static DateFormat ISODATE
          The ISO-date formatter
static double MS100YEAR
          The number of ms in 100 julian years.
static double MSDAY
          The numer of ms in a day.
 
Constructor Summary
Broker()
           
 
Method Summary
static double getEclipticObliquity(Date time)
          Calculates the obliquity of the ecliptic in degrees.
static double getHeight(Date time, double ra, double de, double longitude, double latitude)
          Calculates the height above the horizon for a given astronomical object at a certain site, for time time.
static double getJd(Date time)
          Gets the julian date from a date object.
static double getJulianCentury(Date time)
          Calculates the julian centruries since 2000.0 from a date object.
static double getSidereal(Date time, double longitude)
          Calculates the apparent sidereal time for a given time and longitude in degrees.
static double getSolLambda(Date time)
          Calculates the solar apparent ecliptic longitude in degrees.
static double getSunHeight(Date time, double longitude, double latitude)
          Returns the solar hight for a given time and a certain location.
static boolean isObservable(Date time, double longitude, double latitude, double ra, double de)
          Returns true, if the given target is currently observable at this location.
static boolean isObservable(Date time, double longitude, double latitude, double ra, double de, double maxsol)
          Returns true, if the given target is currently observable at this location.
static boolean isObservable(Date time, double longitude, double latitude, double ra, double de, double minheight, double maxsol)
          Returns true, if the given target is currently observable at this location.
static boolean isObservable(double longitude, double latitude, double ra, double de)
          If the time of the observation is unknown, we can deduce if the target might be visible at all.
static boolean isObservable(double longitude, double latitude, double ra, double de, double minheight)
          If the time of the observation is unknown, we can deduce if the target might be visible at all.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

MS100YEAR

public static final double MS100YEAR
The number of ms in 100 julian years.

See Also:
Constant Field Values

MSDAY

public static final double MSDAY
The numer of ms in a day.

See Also:
Constant Field Values

ANULL

private static final double ANULL
The constant coefficient in geometric mean anomaly.

See Also:
Constant Field Values

BNULL

private static final double BNULL
The linear coefficient in geometric mean anomaly.

See Also:
Constant Field Values

CNULL

private static final double CNULL
The quadratic coefficient in geometric mean anomaly.

See Also:
Constant Field Values

AM

private static final double AM
The constant coefficient in geometric mean longitude.

See Also:
Constant Field Values

BM

private static final double BM
The linear coefficient in geometric mean longitude.

See Also:
Constant Field Values

CM

private static final double CM
The quadratic coefficient in geometric mean longitude.

See Also:
Constant Field Values

A1EQC

private static final double A1EQC
The constant coefficient in equation of center of the sun.

See Also:
Constant Field Values

B1EQC

private static final double B1EQC
The linear coefficient in equation of center of the sun.

See Also:
Constant Field Values

C1EQC

private static final double C1EQC
The quadratic coefficient in equation of center of the sun.

See Also:
Constant Field Values

A2EQC

private static final double A2EQC
The constant coefficient in equation of center of the sun.

See Also:
Constant Field Values

B2EQC

private static final double B2EQC
The linear coefficient in equation of center of the sun.

See Also:
Constant Field Values

A3EQC

private static final double A3EQC
The linear coefficient in equation of center of the sun.

See Also:
Constant Field Values

ALAM

private static final double ALAM
The constant coefficient in apparent longitude.

See Also:
Constant Field Values

BLAM

private static final double BLAM
The linear coefficient in apparent longitude.

See Also:
Constant Field Values

ANU

private static final double ANU
Constant coefficient for calculating mean perihelium.

See Also:
Constant Field Values

BNU

private static final double BNU
Linear coefficient for calculating mean perihelium.

See Also:
Constant Field Values

ASUN

private static final double ASUN
The constant coefficient, ecliptic obliquity.

See Also:
Constant Field Values

BSUN

private static final double BSUN
The linear coefficient, ecliptic obliquity.

See Also:
Constant Field Values

CONST

private static final double[] CONST
Constants required for the siderael time algorithm.

DEFAULTSOL

public static final double DEFAULTSOL
Default maximum solar height.

See Also:
Constant Field Values

DEFAULTHEIGHT

public static final double DEFAULTHEIGHT
Default minimum object height.

See Also:
Constant Field Values

ISODATE

private static final DateFormat ISODATE
The ISO-date formatter

Constructor Detail

Broker

public Broker()
Method Detail

getJd

public static double getJd(Date time)
Gets the julian date from a date object.

Parameters:
time - Date of observation.
Returns:
The JD correponding to the date object.

getJulianCentury

public static double getJulianCentury(Date time)
Calculates the julian centruries since 2000.0 from a date object.

Parameters:
time - Date of observation.
Returns:
The passed julian centuries since 2000.0.

getSidereal

public static double getSidereal(Date time,
                                 double longitude)
Calculates the apparent sidereal time for a given time and longitude in degrees. Approximate formular.

Parameters:
time - Date of observation.
longitude - Geographical longirude in degrees, W is negative.
Returns:
The local apparent sidereal time in degrees.

getSolLambda

public static double getSolLambda(Date time)
Calculates the solar apparent ecliptic longitude in degrees. Refer to NOAA solar position calculator.

Parameters:
time - Date of observation.
Returns:
Apparent ecliptical longitude of the Sun in degrees.

getEclipticObliquity

public static double getEclipticObliquity(Date time)
Calculates the obliquity of the ecliptic in degrees. Refer to NOAA solar position calculator.

Parameters:
time - Date of observation.
Returns:
Ecliptic Obliquity in degrees.

getSunHeight

public static double getSunHeight(Date time,
                                  double longitude,
                                  double latitude)
Returns the solar hight for a given time and a certain location. Calculates right ascension and declination of sun and get's this object's height via getHeight(java.util.Date, double, double, double, double).

Parameters:
time - Date of the observation as a Java Date object.
longitude - Longitude of site, in degrees, W negativ.
latitude - Latitude of site, in degrees.

getHeight

public static double getHeight(Date time,
                               double ra,
                               double de,
                               double longitude,
                               double latitude)
Calculates the height above the horizon for a given astronomical object at a certain site, for time time. The right ascension and declination of the object are apparent right ascension and declination of the object, both in degrees. The telescope's location is defined by its longitude and latitude, both in degrees. Longitude is negative for Western longitudes.
Does not include refraction or aberration.

Parameters:
time - Date of the observation as a Java Date object.
ra - Right ascension of object, degrees.
de - Declination of object, degrees.
longitude - Longitude of site, in degrees, W negativ.
latitude - Latitude of site, in degrees.

isObservable

public static boolean isObservable(double longitude,
                                   double latitude,
                                   double ra,
                                   double de)
If the time of the observation is unknown, we can deduce if the target might be visible at all. Note: Longitude and ra are not used.

Parameters:
ra - Right ascension of object, degrees.
de - Declination of object, degrees.
longitude - Longitude of site, in degrees, W negativ.
latitude - Latitude of site, in degrees.

isObservable

public static boolean isObservable(double longitude,
                                   double latitude,
                                   double ra,
                                   double de,
                                   double minheight)
If the time of the observation is unknown, we can deduce if the target might be visible at all. Note: Longitude and ra are not used.

Parameters:
ra - Right ascension of object, degrees.
de - Declination of object, degrees.
longitude - Longitude of site, in degrees, W negativ.
latitude - Latitude of site, in degrees.
minheight - Star should be at least that high.

isObservable

public static boolean isObservable(Date time,
                                   double longitude,
                                   double latitude,
                                   double ra,
                                   double de)
Returns true, if the given target is currently observable at this location.

Parameters:
time - Date of the observation as a Java Date object.
ra - Right ascension of object, degrees.
de - Declination of object, degrees.
longitude - Longitude of site, in degrees, W negativ.
latitude - Latitude of site, in degrees.

isObservable

public static boolean isObservable(Date time,
                                   double longitude,
                                   double latitude,
                                   double ra,
                                   double de,
                                   double maxsol)
Returns true, if the given target is currently observable at this location.

Parameters:
time - Date of the observation as a Java Date object.
ra - Right ascension of object, degrees.
de - Declination of object, degrees.
longitude - Longitude of site, in degrees, W negativ.
latitude - Latitude of site, in degrees.

isObservable

public static boolean isObservable(Date time,
                                   double longitude,
                                   double latitude,
                                   double ra,
                                   double de,
                                   double minheight,
                                   double maxsol)
Returns true, if the given target is currently observable at this location.

Parameters:
time - Date of the observation as a Java Date object.
ra - Right ascension of object, degrees.
de - Declination of object, degrees.
longitude - Longitude of site, in degrees, W negativ.
latitude - Latitude of site, in degrees.
minheight - Star should be at least that high.
maxsol - Sun should be at least this low.
Overview  Package   Class  Use  Tree  Deprecated  Index  Help 
 PREV CLASS   NEXT CLASS FRAMES    NO FRAMES    
SUMMARY: NESTED | FIELD | CONSTR | METHOD DETAIL: FIELD | CONSTR | METHOD