Ignore:
Timestamp:
02/03/05 19:17:29 (20 years ago)
Author:
gaug
Message:
*** empty log message ***
File:
1 edited

Legend:

Unmodified
Added
Removed
  • trunk/MagicSoft/GRB-Proposal/Monitor.tex

    r6235 r6248  
    2121
    2222
    23 \subsection{The connection to the GCN}
     23\subsection{The Connection to the GCN}
    2424
    2525The connection to the \g is performed by {\it gspot} through a
     
    4343
    4444In case of an alert {\it gspot} stores the informations and enters
    45 an {\bf Alarm State}. The duration of the alarm state depends on the following parameters:
     45an {\bf Alarm State}. The duration of the alarm depends on the following parameters:
    4646
    4747\begin{itemize}
    48 \item {\bf Darkness of the sky}: Determined from the distance of the sun
    49 to the astronomical horizon of 108$^\circ$ zenith;
     48\item {\bf Darkness of the sky}: The Sun has to be below
     49to the astronomical horizon at 108$^\circ$ zenith.
    5050\item {\bf Position of GRB}: The GRB equatorial
    5151coordinates are transformed into local horizontal coordinates.
    5252The resulting GRB zenith angle has to be smaller than 70$^\circ$. In case that the moon is
    53 shining, the zenith angle limit is reduced to 65$^\circ$;
     53shining, the zenith angle limit is reduced to 65$^\circ$.
    5454\item {\bf Position of moon}: The angular
    5555distance from the GRB to the moon has to be at least 30$^\circ$.
    5656\end{itemize}
    5757
    58 If one or more of these conditions fail, {\it gspot} enters into a \text
    59 {yellow}{\bf Yellow Alarm State}. It means that the GRB is not observable at the moment.
    60 Currently the program does not calculate if and when the GRB will become observable for \ma.
    61 If all conditions mentioned above are satisfied, {\it gspot} enters into a \textcolor{red}{\bf Red Alarm State}, it means that the GRB is considered to be observable now.\\
    62 
    63 In both cases (in \textcolor{red}{RED} and \textcolor{yellow}{YELLOW} alarm state) {\it gspot} establishes the communication with the CC and sends the GRB equatorial coordinates (RA/DEC J2000).
    64 For the communication with CC the format defined in~\cite{CONTROL} is used. In the same time
    65 the shifters and the GRB-MAGIC group is contacted in different ways as described in the next sessions.
    66 
    67 \subsection{The interface to the Central Control}
    68 
    69 An interface of {\it gspot} sends all the relevant information to {\it arehucas}.
    70 In the case of {\bf NO Alarm State} the standard packages, containing the main global status
    71 of the two subsystems, are continuously exchanged between CC and {\it gspot}.
    72 In the alert case {\it gspot} starts to send to CC special alert packages,
    73 containing information about of the GRB and the ''color'' of the alert.
    74 The exchange of the alert packages continues until the following steps occur:
     58If one or more of these conditions fail, {\it gspot} enters into a
     59{\color[rgb]{0.9,0.75,0.}\bf Yellow Alarm State}: The GRB is not observable at the moment.
     60Currently, the program does not calculate if and when the GRB will become observable for \ma.
     61If all the  mentioned conditions are satisfied,
     62{\it gspot} enters into a \textcolor{red}{\bf Red Alarm State}, it means that the GRB is considered to be observable now.\\
     63
     64In both cases (in \textcolor{red}{\bf RED} and {\color[rgb]{0.9,0.75,0.}\bf YELLOW} Alarm State), {\it gspot} establishes the communication with the CC and sends the GRB equatorial coordinates (RA/DEC J2000).
     65For the communication with CC the format defined in~\cite{CONTROL} is used. At the same time,
     66the shifters and the GRB-MAGIC group is contacted.
     67
     68\subsection{The Interface to the Central Control}
     69
     70An interface of {\it gspot} sends all the relevant information to the CC.
     71In the case that {\it gspot} is not in alarm state,
     72the standard packages are continuously exchanged between CC and {\it gspot}, containing the main global status
     73of the two subsystems.
     74In the alert case, {\it gspot} starts to send  special alert packages to the CC,
     75containing information about the GRB and the ''color'' of the alert.
     76The exchange of the alert packages continues until:
    7577
    7678\begin{itemize}
    77 \item {\it gspot} receives from {\it arehucas} the confirmation
    78 that it has received the alert notice; {\it arehucas} must send the alert back in order
    79 to perform a cross-check of the relevant data
    80 \item the alarm state expire after {\bf 5 hours}
     79\item {\it gspot} receives from the CC the confirmation
     80that the alert notice has been received; The CC must send back the alert in order
     81to perform a cross-check of the relevant data.
     82\item the alarm state expires after {\bf 5 hours}
    8183\end{itemize}
    8284
    83 At the moment {\it arehucas} informs the shift crew about the alert and takes
    84 further steps only in case of red alerts. In this case a pop-up window
     85The CC informs the shift crew about the alert and undertakes
     86further steps only in case of a \textcolor{red}{\bf red alerts}.
     87In this case, a pop-up window
    8588appears with all the alert information received by the burst monitor.
    8689The operator has to confirm the notice by closing the pop-up window.
    8790He can decide to stop the current scheduled observation and to point the GRB.
    88 A new button in the CC will be displayed and allows to point the telescope to
    89 the GRB coordinates by pushing it.
    90 
    91 \subsection{GRB archive and emails to the GRB-mailing list}
     91A new button will be displayed in the CC and allows to point the telescope to
     92the GRB coordinates.
     93
     94\subsection{GRB Archive and Emails to the GRB-mailing List}
    9295
    9396In case of an alert -- even if it did not contain the necessary coordinates -- the
    9497information is  translated into ''human language'' and stored in ASCII files.
    95 At the same time an e-mail is sent to the MAGIC GRB-mailing list.
    96 
    97 \subsection{The GRB web page}
    98 
    99 The status of the GRB Alert System and relevant informations about the lastest
    100 alert are displayed on a separate web page. The page is hosted at the web server in La Palma.
    101 The address is the following:\\
     98At the same time, an e-mail is sent to the MAGIC GRB-mailing list
     99{\it GrB@magic.iac.es}.
     100
     101\subsection{The GRB Web Page}
     102
     103The status of the GRB Alert System and relevant informations about the latest
     104alert are displayed on a separate web page. The page is hosted at the web server in La Palma a
     105and can be accessed under:\\
    102106
    103107\qquad \qquad http://www.magic.iac.es/site/grbm/\\
     
    106110the status of the Burst Alarm System can be checked by the shifters and from outside.
    107111
    108 \subsection{The acoustic alert}
     112\subsection{The Acoustic Alert}
    109113
    110114A further CC-independent acoustic alarm called {\it phava}
    111115(PHonetic Alarm for Valued Alerts) will be installed
    112 in La Palma very soon. It will provide a loud acoustic signal
    113 even if {\it arehucas} is switched off, so that persons in the counting house
    114 will be noticed about the alert situation. The signal will be on as long as
    115 {\it gspot} stays in alarm state, and in any case for a minimum of 1 minute.
    116 This device feature also a display with the status of the system and the alert.
    117 
    118 \subsection{Summary of alerts received until now}
    119 
    120 Since July, 15th 2004 {\it gspot} has been working stably at La Palma.
    121 It received about 100 alerts from HETE-2 and INTEGRAL, out of which
    122 only 21 contained GRB's coordinates. Time delays
    123 were in the order of several minutes to tens of minutes. The Burst Monitor can be considered bug-free since
    124 November 2004. From this moment we received the following two significant alerts:\\
     116in La Palma soon. It will provide a loud acoustic signal
     117even if the CC is switched off, so that persons in the counting house
     118can be noticed about the alert situation. The signal will be on as long as
     119{\it gspot} remains in alarm state, and for a minimum of 1 minute.
     120The device features also a display with the status of the system and the alert.
     121
     122\subsection{Summary of Alerts Received Until Now}
     123
     124Since July 15$^{th}$, 2004, {\it gspot} has been working stably at La Palma.
     125It has received about 100 alerts from HETE-2 and INTEGRAL, out of which
     12621 contained GRB's coordinates. Time delays to the onset of the burst
     127were of the order of several minutes to tens of minutes. The Burst Monitor can be considered stable
     128since November, 2004. Since then, we have received the following two significant alerts:\\
    125129
    126130\begin{tabular}{lllcccl}
     
    129133\end{tabular}
    130134
    131 In both cases the weather conditions at La Palma were very bad.
    132 
    133 \subsection{Experience of SWIFT GRBs until now}
    134 
    135 According to the \sw homepage~\cite{SWIFT} the satellite detected 12 GRBs since mid December last year.
    136 The bursts were detected by chance during the comissioning phase. The satellite did not send
    137 the coordinates on time to \g. Anyhow, in the current sample are two bursts
    138 which in principle could have been observed by \ma:\\
     135In both cases the weather conditions at La Palma were bad.
     136
     137\subsection{Experience from SWIFT GRBs until now}
     138
     139According to the \sw home page~\cite{SWIFT}, the satellite has detected 12 GRBs since mid-December last year.
     140The bursts were detected by chance during the commissioning phase. The satellite did not send
     141the coordinates to the \g on time. The current sample contains two bursts
     142which could have been observed by \ma:\\
    139143
    140144\begin{tabular}{lllcc}
     
    143147\end{tabular}
    144148
    145 \subsection{Comparison between the satellite orbits}
    146 
    147 Figure~\ref{fig:orbit} show the difference between the orbits of the \sw, \he and \ig satellite.
    148 The \sw and \he satellites are situated in a circular orbit with 20.6$^\circ$ respectivly 2$^\circ$ inclination. The revolution period of the \sw and \he satellite add up to 100min. The \ig satellite is situated in an highly eccentric orbit with a revolution period around the Earth of three sidereal days.
     149\subsection{Comparison between the Satellite Orbits}
     150
     151Figure~\ref{fig:orbit} shows the orbits of the \sw, \he and \ig satellites.
     152The \sw and \he satellites are situated in a circular orbit with
     15320.6$^\circ$ and 2$^\circ$ inclination, respectively.
     154One revolution of the \sw and \he satellites last about 100\,min.
     155The \ig satellite has a
     156highly eccentric orbit with a revolution period of three sidereal days around the Earth.
    149157
    150158\par
    151159
    152 It is difficult to make strong conclusions from the individual satellite orbit. The orientation of the satellite FOV is influenced by the scheduled targets. Hovewer, \sw is the satellite with the largest inclination and overlaps mostly with the FOV of \ma. This increases the chance to recive {\bf Red Alarm} from this satellite.
     160It is difficult to draw strong conclusions from the individual satellites' orbits.
     161The orientation of the satellites' FOV is influenced by the scheduled targets.
     162However, \sw is the satellite with the largest inclination and overlaps mostly with the FOV of \ma.
     163This increases the chance to receive {\bf Red Alarms} from this satellite.
    153164
    154165\begin{figure}[htp]
    155166\centering
    156167\includegraphics[width=0.7\linewidth]{GCNsatellites.eps}
    157 \caption{Orbits of the \sw, \he and \ig satellites}
     168\caption{Orbits of the \sw (top), \he (center) and \ig (bottom) satellites: The pointed lines
     169show the orbit while the drawn lines show the horizon of the Sun. Here, a typical night at
     170La Palma is shown. The \sw satellite passes over the Roque seven times each night.}
    158171\label{fig:orbit}
    159172\end{figure}
    160173
    161 \subsection{Routines to be defined}
     174\subsection{Routines to Be Defined}
    162175
    163176The Burst Alarm System is currently able to provide the minimum
     
    168181\item {\bf Yellow Alarm strategy}:
    169182The strategy to follow a {\bf Yellow Alarm} is not defined yet.
    170 In such a case the CC does not undertake any steps,
    171 except confirming the alarm notice to the Burst Monitor. We do not
    172 calculate if and when the GRB will become observable.
    173 It would make sense to check if during the period of 5 hours we could point to the burst.
    174 Then, the Alarm System should change to the {\bf Red Alarm State}
    175 at that time and allow the observation.
     183In such a case, the CC does not undertake any steps,
     184except confirming the alarm notice to the Burst Monitor. We have not
     185calculated yet if and when the GRB will become observable.
     186It would make sense to check if we could point to the burst during the period of 5 hours.
     187The Alarm System should change to a {\bf Red Alarm State}, then.
    176188
    177189\item {\bf Sequence of alerts}:
    178190How to deal with new alerts that are distributed during the time
    179 that {\it gspot} is in alarm state? Currently {\it gspot}
     191that {\it gspot} is in alarm state? Currently, {\it gspot}
    180192locks its alert status until it exits the alarm state (see session 2.2).
    181 This feature was implemented to avoid any loose of the GRB information.
    182 Such a situation can occur when for example more than one burst alert is send before
    183 the shift crew starts the CC. To solve the problem we will change the {\it gspot} routine by implementing a list of the available GRB alerts.
     193This feature was implemented to avoid any loss of GRB information.
     194Such a situation can occur for example if more than one burst alert is sent before
     195the shift crew launches the CC.
     196To solve this problem, we will change the {\it gspot} routine
     197by implementing a list of all available GRB alerts.
     198
    184199
    185200\par
    186201
    187202If more than one alert is present in the list, the program
    188 will weight the possible GRBs on the following criteria:
     203will weight the possible GRBs according to the following criteria:
    189204(1) the total time of observability within the canonical 5 hours,
    190205(2) the intensity of the burst and
    191206(3) the time until the GRB becomes observable.
    192 The information of the best GRB will be send to the CC.
     207The information of the best GRB will be sent to the CC.
    193208
    194209\end{itemize}
Note: See TracChangeset for help on using the changeset viewer.