forked from spacecruft/SNOUG
92 lines
2.6 KiB
TeX
92 lines
2.6 KiB
TeX
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% Solve.tex
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% SatNOGS Optical Unofficial Guide
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% Copyright (C) 2022, Jeff Moe
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% This document is licensed under the Creative Commons Attribution 4.0
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% International Public License (CC BY-SA 4.0) by Jeff Moe.
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%
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\section{Plate Solver}
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\label{sec:plate-solver}
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\index{plate solver}
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A ``plate solver'' will take an image of stars and detect the time and place
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of the picture. There are two main steps:
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\begin{enumerate}
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\item Extract stars from an image, such as a \gls{FITS} file generated by \texttt{stvid}.
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\item ``Solve'' the image of the stars in the image against vast databases of star images.
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\end{enumerate}
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See below for a list of software tools that detect/extract stars from
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images (e.g. \gls{FITS}).
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\begin{itemize}
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\item Source Extractor.
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\item XXX Kstars with ekos adds \texttt{Internal SEP}.
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\item XXX Kstars with ekos adds \texttt{Builtin method for solver}.
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\end{itemize}
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\index{Souce Extractor}\index{Kstars}\index{ekos}
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See below for a list of plate solvers than can be used.
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\begin{itemize}
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\item astrometry.net locally.
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\item astrometry.net Internet.
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\item astap.
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\item Watney.
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\end{itemize}
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\index{astrometry.net}\index{astap}\index{Watney}
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\section{Source Extractor}
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\index{Source Extractor}
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\texttt{Source Extractor}, formerly \texttt{SExtractor} and some other names,
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is an application to extract stars from images. The software has been
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widely used for many years.
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\url{https://www.astromatic.net/software/sextractor}
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\section{astrometry.net}
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\index{astrometry.net}
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Astrometry.net is a website and software that can be run locally to solve
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a plate of stars that has been extracted from \texttt{Source Extractor}. XXX
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\index{Source Extractor}
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% https://nova.astrometry.net/
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\begin{figure}[h!]
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\includegraphics[keepaspectratio=true,height=1.10\textheight,width=1.00\textwidth,angle=0]{astrometry-web.png}
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\caption{nova.astrometry.net website.}
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\label{fig:astrometry-web-web}
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\index{astrometry.net}
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\end{figure}
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\fbox{
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\parbox{\linewidth}{
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\textcolor{red}{NOTICE:} \\
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Using astrometry.net online requires an account with non-libre services.
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The astrometry.net software can be installed locally to avoid this.
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\index{proprietary}
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}
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}
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\section{Star Databases}
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\index{star database}
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To use a plate solver, you will need star databases. They can get large.
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The \texttt{stvid} application includes a basic star database.
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XXX The \texttt{4200} series is also recommended.
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\section{World Coordinate System}
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WCS info. XXX
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\section{Plate Solving with \texttt{stvid}}
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Use the \texttt{process.py} scripts described at XXX to solve plates
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with \texttt{stvid}.
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