114 lines
3.2 KiB
TeX
114 lines
3.2 KiB
TeX
%
|
|
% Solve.tex
|
|
%
|
|
% SatNOGS Optical Unofficial Guide
|
|
%
|
|
% Copyright (C) 2022, Jeff Moe
|
|
%
|
|
% This document is licensed under the Creative Commons Attribution 4.0
|
|
% International Public License (CC BY-SA 4.0) by Jeff Moe.
|
|
%
|
|
|
|
\section{Plate Solver}
|
|
\label{sec:plate-solver}
|
|
|
|
A ``\gls{plate-solver}'' will take an image of stars and detect the time and place
|
|
of the picture. There are two main steps:
|
|
|
|
\begin{mdframed}[backgroundcolor=blue!10,linecolor=blue!30]
|
|
\begin{enumerate}
|
|
\item Extract stars from an image, such as a \gls{FITS} file generated by \texttt{\gls{stvid}}.
|
|
\item ``Solve'' the image of the stars in the image against vast databases in a
|
|
\gls{star-catalogue}.
|
|
\end{enumerate}
|
|
\end{mdframed}
|
|
|
|
See below for a list of software tools that detect/extract stars from
|
|
images (e.g. \gls{FITS}).
|
|
\index{detect}
|
|
|
|
\begin{mdframed}[backgroundcolor=blue!10,linecolor=blue!30]
|
|
\begin{itemize}
|
|
\item Source Extractor.
|
|
\item \gls{KStars} with Ekos adds \texttt{Internal SEP}.
|
|
\item \gls{KStars} with Ekos adds \texttt{Builtin method for solver}.
|
|
\end{itemize}
|
|
\end{mdframed}
|
|
\index{Source Extractor}\index{Ekos}
|
|
|
|
See below for a list of \glspl{plate-solver} that can be used.
|
|
|
|
\begin{mdframed}[backgroundcolor=blue!10,linecolor=blue!30]
|
|
\begin{itemize}
|
|
\item astrometry.net locally.
|
|
\item astrometry.net Internet.
|
|
\item astap.
|
|
\item Watney.
|
|
\end{itemize}
|
|
\end{mdframed}
|
|
\index{astap}\index{Watney}\index{astrometry.net}
|
|
|
|
|
|
\section{Source Extractor}
|
|
\label{sec:Source Extractor}
|
|
\index{Source Extractor}
|
|
|
|
\texttt{Source Extractor}, formerly \texttt{SExtractor} and some other names,
|
|
is an application to extract stars from images. The software has been
|
|
widely used for many years.
|
|
|
|
\url{https://www.astromatic.net/software/sextractor}
|
|
|
|
|
|
\section{astrometry.net}
|
|
|
|
Astrometry.net is a website and software that can be run locally to solve
|
|
a plate of stars that has been extracted from \texttt{Source Extractor}. XXX
|
|
\index{Source Extractor}\index{astrometry.net}
|
|
|
|
% https://nova.astrometry.net/
|
|
\begin{figure}[h!]
|
|
\begin{framed}
|
|
\centering
|
|
\includegraphics[keepaspectratio=true,height=0.60\textheight,width=0.60\textwidth,angle=0]{astrometry-web.png}
|
|
\caption{nova.astrometry.net website.}
|
|
\label{fig:astrometry-web-web}
|
|
\end{framed}
|
|
\end{figure}
|
|
|
|
\fbox{
|
|
\parbox{\linewidth}{
|
|
\textcolor{red}{NOTICE:} \\
|
|
Using astrometry.net online requires an account with non-\gls{libre} services.
|
|
The astrometry.net software can be installed locally to avoid this.
|
|
\index{proprietary}\index{astrometry.net}
|
|
}
|
|
}
|
|
|
|
|
|
\section{Star Catalogues}
|
|
\label{sec:star-catalogues}
|
|
To use a \gls{plate-solver}, you will need \glspl{star-catalogue}. They can get large.
|
|
The \texttt{stvid} application includes a basic \gls{star-catalogue}.
|
|
XXX The \texttt{4200} index series is also recommended.
|
|
|
|
|
|
\section{World Coordinate System}
|
|
\label{sec:wcs}
|
|
\gls{WCS} info. XXX
|
|
|
|
|
|
\section{SIP}
|
|
\label{sec:sip}
|
|
\gls{SIP} info. XXX
|
|
|
|
|
|
\section{Plate Solving with \texttt{stvid}}
|
|
\label{sec:plate-solving-stvid}
|
|
\index{process}
|
|
|
|
Use the \texttt{process.py} scripts described in section \ref{sec:plate-solver},
|
|
page \pageref{sec:plate-solver}, to solve plates
|
|
with \texttt{\gls{stvid}}.
|
|
|