modulation_index

This is code to modify an existing installation of the PALFA pipeline, which is based on searching with PRESTO, to execute Laura Spitler's modulation index methods.

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Instructions

Summary

In these notes, we show how to incorporate maskdata into PRESTO. This is necessary to run Laura Spitler's modulation index single pulse search as implemented in the PALFA pipeline.

The maskdata task is a copy of PRESTO's prepdata with one key addition. It writes a headerless SIGPROC filterbank file of the raw pulsar data with the rfi mask applied. This is used later in the single pulse search.

Changes

New:

• $PRESTO/src/mask_data.c

Modified:

• $PRESTO/src/backend_common.c
• $PRESTO/include/backend_common.h
• $PRESTO/src/Makefile

All of these files (and the original files, prefixed with "save_") can be found in the changes folder.

mask_data.c

This is a copy of prepdata.c with all function calls to "read_psrdata()" changed to "read_psrdata_mask()". The definitions of these two functions are in backend_common.c.

backend_common.c

This contains the functions used for reading in pulsar data. The main change we make is to add "read_psrdata_mask()". This function is a copy of "read_psrdata()", but with a write step that writes the masked data to file. The only changes are for opening and writing this file. The file name is hard-coded as "raw_data_with_mask.fits".

backend_common.h

Need to add "read_psrdata_mask" to the header file.

Makefile

Need to add a maskdata target in the Makefile. Also need to add to list of binaries.

Calculating the modulation index of single pulse candidates in PALFA data

mi_src.tar contains:

• palfa_calc_mi.c
• mock_spec.h

We shouldn't need any more dependencies, so just build:

$ gcc -Wall palfa_calc_mi.c -o palfa_mi -lm

The executable is called "palfa_mi" in the PALFA pipeline (called in the PALFA2_presto_search_noaccel.py python script), so we want to make sure it has the same name.