Comparison of different photometric algorithms on Pi of the Sky data.

Pi of the Sky is a system of wide field-of-view robotic telescopes,
which search for short timescale astrophysical phenomena, especially
for prompt optical GRB emission. The system was designed for autonomous
operation, monitoring a large fraction of the sky with 12m-13m range and
time resolution of the order of 1 - 100 seconds. System design and
observation strategy was successfully tested with a prototype detector
in Chile, operational since 2004. In July 2013 the final Pi of the Sky
detector system, with 16 CCD cameras on 4 mounts, was comissioned in
the INTA El Arenosillo Test Centre in Spain resulting in a total coverage
of about 6000 square degrees.

Luiza is a dedicated framework developed for efficient offline data
processing, implemented in C++. Data analysis is divided into small,
well-defined steps, which are implemented as so called processors.
The framework allows to define the processor choice and their order, as
well as all the required parameters at runtime, in a simple XML
steering file.

Three different photometry algorithms were implemented in Luiza.
The algorithm based on ASAS photometry is implemented in three processors.
First processor searches for stars in the analysed images and extracts
parameters if the PSF Gaus Profile. The next one convolues the image
with the Gaussian kernel and used the resulting image for star
recognition. In the last step object brightnesses are calculated.
Results obtained from the ASAS photometry are compared with the new
photometry algorithm and with the simple aperture photometry implemented
previoulsly. Results concerning analysis of single images with different
exposure times, as well as of stacked frames are presented.

Author: Ɓukasz Obara
Conference: Title