Pilot Survey
In 2000 the
Arecibo Pulsar
Research Group began a low-level pilot survey
to test predictions about the pulsar yield of
the large-scale ALFA surveys. The pilot survey
focuses on a smaller part of the sky, but it
already has several hundred gigabytes of data.
-
Each raw data set = two dimensional of size 256
x 4 Megasamples with 2 bytes/sample = 2 Gigabytes.
-
The entire survey will result in about 1000 of
these data sets or about 2 terabytes.
-
Pilot survey has 800 gigs of raw binary data.
Data Description
The sky survey is divided into a grid of galactic
longitude vs. latitude. Each cell of the grid
corresponds to a particular pointing of the telescope
(see
grid chart). Therefore, all of the data is
indexed by l_beam (longitude grid index), b_beam
(latitude grid index), and the modified julian
date (timestamp).
The raw data from the telescope is by far
the largest component of the pulsar data. Specialized
programs analyze the raw data and generate
intermediate data products which help researchers
identify interesting signals in the data. Due to
its very large size, it is not currently available
online.
The intermediate data products consist of
the periodic candidate lists, the single giant
pulse lists, and various diagnostic information.
There are also a number of plots and graphs to
help visualize the data. The database contains all
of the intermediate data products and this website
is mainly concerned with helping users search the
intermediate data.
The final products are the catalogs of
identified pulsars and their associated folded pulse
profiles.
In total, we get approximately 10 Megabytes of
intermediate data products for each raw data file, a
reduction factor of 2 Gbytes / 10 Mbytes ~ 200. Over
the 1000 raw data sets, we therefore have about 10
Gbytes of intermediate data products.
Data Portal