April 2005 ALMA Offline software test NAME: Martin Zwaan Questionnaire on testing experience 1. Please list briefly your background in the following areas: A. Radio Interferometry ((sub)millimeter or centimeter) I've worked with data from the VLA, Westerbork, ATCA and GMRT. This was always 21cm data. B. Experience with VLA and/or PdBI data I've done a few projects with the VLA (21cm), never with PdB C. Astronomical Data Reduction packages: - AIPS used extensively for VLA, WSRT, ATCA and GMRT - MIRIAD I've used MIRIAD, but preferred AIPS also for ATCA data - MMA no - Gildas/Clic no - AIPS++ livedata and gridzilla, and TST1.1 D. How much experience have you had with the AIPS++ software package before this test? I've had some experience with the aips++ packages livedata and gridzilla that were developed for the Parkes Telescope. These are basically stand-alone packages. Experience with aips++ comes mostly from TST1.1 2. Please identify which dataset you processed during this test: A. VLA continuum observations of Orion 3. Were you able to combine the single dish and interferometric data using feather and deconvolution techniques? If not, why? Please comment on specific steps if desired (comments can be positive or negative, you may not have tried all steps): A. Feather images or image cubes provided by Offline subsystem Yes. This worked without any problems B. Feather single dish image provided and interferometer image that you created from the dataset provided. Yes. The actual feathering is very straightforward and extremely fast. Creating a MEM image with a low noise level and realistic total flux was more challenging. This is probably mostly due to me not having much experience in using MEM. I have played a lot with the parameters niter, sigma, and targetflux to get a nice looking image, but the result is far from unique. I haven't tried to create a feathered map from a CLEANed inter- ferometer map and the SD image. C. Deconvolve the single dish and interferometer data using the single dish image to create an input model. Yes. I constructed a clean components model from the SD data using 'makemodelfromsd', and used this as a constraint in CLEAN. This all worked fine. Please identify any problems you had during imaging. No major problems. I found it hard to get a nice MEM image, but that's a more a problem inherent to MEM than to aips++. MS-Clean can be a bit slow, but of course it is computationally very demanding. 4. Were you able to analyze the images adequately to determine if the results you obtained were scientifically reasonable (e.g. display the image, calculate RMS and peak, make a moment map or take a spectrum)? If not, why? Yes this is trivial using the dv.gui, or with image.statistics. 5. Please summarize the final results of your image(s): feathered (MEM VLA maps + SD) - RMS: 10 - 15 mJy/beam - Peak and Total Flux Density: 1.35 Jy/beam, 387 Jy MS-Clean - RMS: 15 - 27 mJy/beam - Peak and Total Flux Density: 1.08 Jy/beam, 409 Jy rms values vary a lot over the images 6. Did you have adequate support during your test? If you contacted the AIPS++ groups for questions or to fix a bug, please comment on the interaction and whether it was helpful. I started the test rather late, but was able to do it without any help from the aips++ group. 7. Was AIPS++ easy to install? If not, why? yes, this worked without a problem. 8. The Synthesis Reduction Cookbook you used for this test is the second version of a comprehensive cookbook for ALMA users. Please evaluate the organization, content, and presentation of the cookbook. It is meant to be the first documentation users will see when they want to reduce ALMA data, it provides background on the code capabilities, and extensive examples. The on-line documentation provides more details and code descriptions. With this in mind, please answer the questions below. If you have detailed comments, please attach them to the end of this questionnaire. - Was the documentation adequate for you to complete your test? Yes. - Do you have any suggestions for how to improve the cookbook? Chapter 5: All the information that one needs to do different kinds of deconcolution, combine single dish and intereferometer data, and mosaicing is included in this chapter, which is great, but I found myself go back and forth a lot in this chapter to find what I needed. Somehow, the order in which things are presented is not always logical. Overall, the cookbook is great and provides a lot of essential information in a very readable format. - Was the on-line documentation helpful: * User Reference Manual? I use this a lot to find out which parameters to use. The reference manual is an essential addition to the cookbook. * Supporting documentation? Yes, all information is included. 9. Roughly how much time did you take to perform the following steps: - Installing aips++: 1h - Imaging: 12h - Analysis: 2h - Filling out this questionnaire: 1h - Evaluating and grading the scientific requirements: 1h - Total time: 17h 10.Please rate your overall testing experience: - excellent X good - fair - poor - horrid 11.Was the test well designed and executed by those in the ALMA offline subsystem (e.g. the subsystem scientist and the Offline subsystem group). If not, can you provide any suggestions for improving the next test? Yes. Although it took me a while to find out what we really have to do. I can image that this is the intended strategy: I suppose it's much better to let us play with aips++ than to give us a detailed check list of things to do. 12.Do you have any additional comments that may help improve test of the offline software in the future?