Cheat-sheet: Recovering NEOs

This document is targeted at advanced users and lists most of the commands needed to recover near-earth objects. For use on your machine you might have to change some/most of the paths.


1) Create a file listing all files to be reduced

This can be done e.g. using the OTA Listener or some other means. Note that if you create the file using the OTA Listener but run the reduction on odidb, you have to replace the /Volumnes by /mnt

Personally what I like to do is the following –  all you need to know is the directory holding your files:

~/bin/podi/ /your/dir/o2014*/*33.fits | tee night.log

in practice, this would look like


~/bin/podi/ /mnt/odifile/archive/podi/WIYN-14A-0633/2014.02.24/o*/*33.fits | tee night.log

You will then get a small night-log that is displayed in the terminal and also written to the file night.log (the name is specified after the “tee”)

On my machine, one example output is the following:

/nas/wiyn/jay-eric/raw/o20140104T215454.1/o20140104T215454.1.33.fits.fz OBJECT 1 odi_r 600.0 Perseus F1 odi_g +03:19:00.988 +41:38:51.476
/nas/wiyn/jay-eric/raw/o20140104T220747.1/o20140104T220747.1.33.fits.fz OBJECT 1 odi_r 600.0 Perseus F1 odi_g +03:18:56.278 +41:39:33.850
/nas/wiyn/jay-eric/raw/o20140104T222345.1/o20140104T222345.1.33.fits.fz OBJECT 1 odi_g 600.0 Perseus F1 odi_g +03:18:56.174 +41:39:28.51
/nas/wiyn/jay-eric/raw/o20140104T223641.1/o20140104T223641.1.33.fits.fz OBJECT 1 odi_g 600.0 Perseus F1 odi_g +03:19:00.537 +41:38:32.357
/nas/wiyn/jay-eric/raw/o20140104T230933.1/o20140104T230933.1.33.fits.fz OBJECT 1 CTIO_Ha 1200.0 NGC2403 Halpha +07:35:15.851 +65:44:39.145
/nas/wiyn/jay-eric/raw/o20140104T233333.1/o20140104T233333.1.33.fits.fz OBJECT 1 CTIO_Ha 1800.0 NGC2403 Halpha +07:35:17.666 +65:45:20.626
/nas/wiyn/jay-eric/raw/o20140105T000825.1/o20140105T000825.1.33.fits.fz OBJECT 1 odi_r 600.0 NGC2403 odi_r +07:35:11.705 +65:44:53.314
/nas/wiyn/jay-eric/raw/o20140105T002143.1/o20140105T002143.1.33.fits.fz OBJECT 1 odi_r 600.0 NGC2403 odi_r +07:35:15.416 +65:45:25.955
/nas/wiyn/jay-eric/raw/o20140105T003538.1/o20140105T003538.1.33.fits.fz OBJECT 1 odi_g 600.0 NGC2403 odi_g +07:35:09.422 +65:44:58.79
/nas/wiyn/jay-eric/raw/o20140105T003538.2/o20140105T003538.2.33.fits.fz OBJECT 1 odi_g 600.0 NGC2403 odi_g +07:35:13.121 +65:45:30.178
/nas/wiyn/jay-eric/raw/o20140105T010157.1/o20140105T010157.1.33.fits.fz OBJECT 1 odi_z 600.0 NGC2403 odi_z +07:35:07.34 +65:45:01.307

You can then edit the file and only pick the lines you need. Also you don’t need to bother deleting the OBJECT etc stuff after the filename, this is automatically ignored 😉


2) Reduce the frames using multicollect

on odidb, go to the /mnt/odifile/qr, and run


~/bin/podi/ -fromfile=YOURFILE -formatout=neo_%OBSID.fits -fixwcs -photcalib -cals=/home/odiobserver/qr_calib/ -nonlinearity

This will produce all output files with the naming convention producing something like neo_20140102T030405.6.fits.

The given parameters are identical to what the SAMPListener uses.

3) Prepare the stacking config file

Create a new file and enter the information for the stacking. An example (let’s call it my.stack) would look like this:


The first filename given is the output filename (it does not matter if you put the output file or the command line options first). All other files are considered input files you want to stack. The remaining options specify the stacking parameters – in the example above this means in the order given:
1) adjust the pixelscale to 0.2”
2) perform background subtraction
3) Skip all OTAs except OTA33
4) Activate non-sidereal motion correction, using the given drift rates and reference frame.

The stacked frame will also contain a new set of timestamps in the output header that correspond to the timing information of the chosen reference frame. Also, all frames with a valid photometric calibration are automatically scaled so that the resulting stacked frame has a photometric zeropoint of 25.0mag.


4) Stack your frames

This is pretty straightforward:

~/bin/podi/ -fromfile=my.stack


5) Inspect the frame and get position and magnitude

For magnitudes, the aperture photometry feature in IRAFs imexam (press ‘a’) should give you calibrated magnitudes as IRAF also assumed a default zeropoint of 25.