OM (OnDA Monitor) is a framework for the development of programs that can monitor x-ray imaging experiments in real-time. It is also a set of ready-to-use monitoring programs.

It is the spiritual successor of the OnDA Project and it is maintained mostly by the same team of developers.

OM offers a set of stable and efficient real-time monitoring programs for the most common types of x-ray imaging experiments. These can be used immediately without modifications or can be easily adapted to meet the users’ requirements. In addition, the project provides a set of modules that can be used to easily develop other monitoring programs, tailored to the characteristics of specific experiments.

OM can process imaging data in the broadest sense: multidimensional pixel-based data (for example: diffraction patterns, photoemission spectrums, images from cameras, microscopes or x-ray detectors), but also any kind of digital output from an instrument or sensor (temperature readouts, beam and pulse energies, etc.).

OM focuses on scalability and portability, in order to facilitate its adoption for a wide array of facilities and instruments. It also strives for stability and performance. To achieve these goals, OM processes data in a multi-node parallel environment, using free and open-source libraries and protocols.

OM is written in Python. The use of the Python programming language, which is particularly suited to rapid development, makes OM easy to modify and to adapt to the requirements of specific experiments.

OM also aims to keep its code base simple and as small. The focus is on providing useful core functionality, while allowing the framework to be expanded with external software. The goal is to avoid reimplementing algorithms that are already better optimized in other software packages.

If you use OM in your experiment, please keep citing the original OnDA paper until a new publication for OM is available:

Mariani V., Morgan A., Yoon C.H., Lane T.J., White T.A., O'Grady C., Kuhn M., Aplin S., Koglin J., Barty A., Chapman H.N., OnDA: online data analysis and feedback for serial X-ray imaging., J. Appl. Crystallogr. 2016 May 23;49(Pt 3):1073-1080. (https://www.ncbi.nlm.nih.gov/pubmed/27275150)

OM is currently developed at the Linac Coherent Light Source facility (LCLS) of the SLAC National Accelerator Laboratory.

However, several collaborators from different institutions all over the world contribute code, testing and support to the project.

The current core development team includes the following people:

• Valerio Mariani (corresponding developer: [email protected])
• Anton Barty
• Thomas Grant
• Alexandra Tolstikova

Several people have, over the years, contributed to the development and testing of OM with code, bug reports, ideas, etc. Some still do, occasionally. The following list might not be exhaustive:

• Steve Aplin
• Henry Chapman
• Jason Koglin
• Manuela Kuhn
• Luca Gelisio
• Mia Lahey-Rudolph
• Thomas J. Lane
• Andrew Morgan
• Christopher O'Grady
• Kanupriya Pande
• Thomas A. White
• Chun Hong Yoon