This is a simple application that allows single-dish radio astronomy, collecting both total-power and spectral data in real time from a SDR device--either a UHD device or a RTL-SDR device. INSTALL ======= Once you've fetched the source (of which this file is a part), you can: make make install If you don't already have 'pyephem' on your system, you'll need to install it. The home page for pyephem is here: You'll need to make certain that both your PATH and PYTHONPATH variables include $HOME/bin, since this application installs parts of itself there, rather than in the system directories. Your .bashrc is the usual place to put these variable settings. USAGE ===== Once it's installed, and you have your PATH and PYTHONPATH set appropriately, you can use: simple_ra --help To get help on the command-line parameters DEVICE NAMING ============= The --devid parameter accepts a device name in the format used by the gr-osmodr "generic" source block, which supports a number of device types, including UHD and RTLSDR devices. This application is only set up to use the UHD and RTLSDR devices. For an RTLSDR device, you use: --devid rtl=0 for the first RTLSDR device --devid rtl=1 for the second RTLSDR device If you have a E4K tuner on your RTLSDR, you can (and probably should) specify the "offset_tune" parameter: --devid rtl=0,offset_tune=1 For an ETTUS UHD-type device (USRP family), you use: --devid uhd=a,type=b100,subdev=A:0 --devid uhd=a,addr=,subdev=A:0 --devid uhd=a,type=usrp1,subdev=A:0 DATA FILES ========== This application produces data files in a directory called "simple_ra_data" in your home directory. Files will accumulate there of two types: tp-YYYYMMDD-HH.dat Which contains total-power data and spec-YYYYMMDD-HH.dat Which contains spectral data total-power data format: HH:MM:SS HH:MM:SS data-value The first time column is UTC, the second is LMST. The data value is a simple floating-point number from the detector output. There will also be an occasional PARAMS block: PARAMS tuned-frequency detector-bandwidth declination The spectral data has a similar format. Data lines are: HH:MM:SS HH:MM:SS [ multiple lines of FFT magnitude values ] There is also a PARAMS block in the same format as the total-power PARAMS block POST-PROCESSING SCRIPTS ======================= There are two scripts that can be used to post-process both total-power and spectral data from the files produced in 'simple_ra_data'. The 'process_simple_tpdat' script is used to process total-power files and produce a graph in a ".png" file. Usage: process_simple_tpdat HH:MM:SS hours-width title output-file Example: process_simple_tpdat 20:00:00 4.0 "GP Transit" gp-transit.png \ ~/simple_ra_data/tp-20130125-*.dat ~/simple_ra-data/tp-20130126*.dat This would produce a plot of the data +/- 2.0 hours centered at an LMST of 20:00:00 in a file called 'gp-transit.png' Similarly, spectral data can be processed, using the 'process_simple_specdat' script: Usage: process_simple_tpdat [-u]|-s] HH:MM:SS HH:MM:SS title outfile Here, we give a time range specified by the two HH:MM:SS parameters. That time range is interpreted either as a UTC time, when you specify -u, or a sidereal time, when you specify -s. Example: process_simple_specdat -s 19:30:00 19:33:00 '21cm spectrum' spectrum.png \ ~/simple_ra_data/spec-20120501*.dat