## Heterodyne Observing Pool

### Database

Please observe all projects for the Heterodyne pool in the project account poolw-13. The project description and status can be found on the Heterodyne pool data base https://pools.iram.es.

### Notes

For each Heterodyne pool project, the pako procedures are in the corresponding subdirectories (e.g. ~/088-08), together with a README describing how the procedures are used, and which weather conditions are needed.

For starting pako, please type goPako, pakodisplay, and pako. Each project should have a script for its general setup, e.g.

@ ~/088-08/setup

Please make sure that the project number is correctly set (the only way to distinguish the Heterodyne pool projects later), and that the doSubmit parameter is set to YES. The results of the online data processing will be written to the folder

/vis/088-08/observationData/mira/

One file per backend and per day will be created into that folder. The plots generated by the online data processing are in

/ncsServer/mrt/ncs/monitor/plots

The lastScan.html file for the display of the online data processing is also in the latter directory.

Please use the Heterodyne pool database at https://pools.iram.es to manage the Heterodyne pool projects. You may use the "observer" account (ask the password to the pool manager (gonzalez@iram.es)).

Once in the Heterodyne pool database, please select the current Heterodyne pool, and you will get the project list. The project status can be one of the following:

• CONTINUE - a project is started and still needs more observing time
• SCHEDULED - a project not yet started, authorized for observing
• ON HOLD - do not observe this project
• DONE - the project is done, do not continue

The visibility of the sources can be checked by looking at the vibility plot (the corresponding button in the menu of the project listing). For each source, the project number xxx-yy.p is indicated, together with the priority p (first integer code, 6 = highest, 1 = lowest). The second integer code is the PC rating for individual objects of a given project (2 = observe, 1 = observe only if time left, 0 = don't observe).

If the weather is uncertain and you want to check the conditions without attributing the observing time to a given project, please type in pako

set project test

In case the weather should be too bad for 1.3mm observations, there are projects with setups for 3mm observations only (called backup projects).

If you prefer to reduce the data yourself with MIRA, please log onto mrt-lx3 and start the package with

cd ~/mira
mira

(default version is gag_may12). If you are not familiar with MIRA, please consult the documentation on http://www.iram.es/IRAMES/otherDocuments/manuals/index.html (there is a cookbook section). If you use the new control system for the first time, plase consult also the PAKO manual (same html link, cookbook recipes in chapters 3 and 4).

### FAQ

1. What is HERA ?
• HERA (HEterodyne Receiver Array) is a receiver consisting of two arrays of 3x3 pixels with 24"spacing. The two arrays have orthogonal polarization (V,H) the two polarizations pointing at identical locations on the sky. HERA is able to follow a source in the sky maintaining the same "footprint". For that reason, HERA is the ideal instrument to do big maps at 1mm in the 30m telescope.
2. What is the Heterodyne pool ?
• The Heterodyne pool is an observing system used in the 30m telescope to optimize the observing time with all heterodyne receivers at the 30m, i.e. HERA and EMIR. Due to the fact that HERA operates at 1mm, it has to be used when the amount of water vapour is below 5mm of precipitable water vapor (pwv). Most of the projects using HERA are grouped in a pool, and they are observed during several weeks in autumn (summer pool), or in winter (winter pool). Three lists of projects are created:
• A list of projects at high frequencies above 300GHz (typically using the E330 receiver) or observations requiring very good conditions, like e.g. observations of H2O. This list is observed when the amount of water vapor in the atmosphere is low (pwv < 2mm) and the pointing stability is very good (differences between two consecutive pointings below 2")

• A list of projects at 1mm, typically using HERA. This list is observed when the amount of water vapor in the atmosphere varies between 5 and 2mm, or if it is below 2mm, but the pointing accuracy is not very good (due to strong wind, anomalous refraction, e.g.)
• A list of projects at low frequency (3mm, using EMIR). This list is observed when the amount of water vapor in the atmosphere is above 5mm.
During a Heterodyne pool week, the astronomers coming to the telescope observe projects from the three lists depending on the weather. This observing mode improves the chances to observe a project, and not to loose time due to bad weather, as it occurs with the projects observed with fixed blocks.
3. How is it decided which project is observed ?
• There are three criteria that are taken into account to decide which project is observed:
• The first one is the weather at the moment of performing the observations. The weather rules mentioned above have to be respected. So, depending on the amount of water vapor (which we can check at every moment with the taumeter, https://mrt-lx3.iram.es/tau/taumeter.html) it is decided which of the three queues is going to be observed.

• The second one is the priority given by the program committee and the LST of the project. Within the HERA pool webpage there is an instrument called visibility plot which represents the visibility of every source of every project ranged by priority rate. The project observed will be the one of highest priority rate which source is visible at the moment of the observation.
• Finally, in case that some projects with the SAME PRIORITY and same visibility are visible, priority is given to the one which observer is at the telescope. In case of doubt, the AoD will decide which project to observe.
4. Who does observe the projects ?
• Observers from the projects included in the pool observe for their own projects and also for other projects (if the weather conditions do not allow to observe their projects). The observers of A-rated projects are expected to come to the telescope (except for projets < 10h). For big A projects (> 40 hours), two or more observers may be needed. Observers of B-rated projects are also invited to come, they can improve their chance to get data: obsevers of B-rated projects coming to the telescope to observe for the Heterodyne pool are "awarded" with some observing time (typically 8h). We need 3 to 4 observers per week, who will observe during the whole week in periods of 6 to 8 hours each.

5. How can I control the status of my project ?
• There is a webpage were you can check at every time if your project has been observed, the time left, where you can read the comments of the observers, ...

https://pools.iram.es Once you are logged in the webpage (send an email to the pool manager to obtain the login and the password), select your observing queue (BACKUP,HERA/E230,E330) and you will see all the projects visible within that queue. You can see the number of the project, the name, the PI, the allocated time, the used time... In the top of the page there is a button called "Visibility plot", where you can display the visibilities of all the sources of the projects. If you tape on the number of a project, you will access to the project page, where you have the specific information about the project, the proposal, the PI email adress, the logsheets, the visibility plot for that project ONLY... Observers of the heterodyne pool are invited to "play" with this page in order to get familiar with it.

6. How do I know if my project has been observed ?
• The AoD at the telescope will send you an email every time your project is observed.
7. How are the projects observed?
• All the projects are observed within the same account, called poolw-13. You can access via:

ssh -X poolw-13@gra-lx1.iram.es In that account there is one folder per project. Each one of those folders (named xxx-yy, as the name given by the PC to your proposal) contains the following data:

• the procedures necessaries to observe the project
• A README file explaining STEP-BY-STEP the things that we have to do to properly observe the project. Please, take into account that this README file should be as clear as possible. You do not know who is going to observe your project. If you want to detect one line, specify the rms or the S/N. A typical README file is sended to the PIs. Please follow that schema as much as possible.
• A LOG file where the observers explain how the observations have been performed, if they have had any problem, and the decissions that they have taken while observing your data.
8. How can I check my data.
• Each project has its own account called as their project number. You can access via:

ssh -X xxx-yy@gra-lx1.iram.es The 30m telescope will generate a calibrated file with your data in the directory observationData/mira, under the name BACKEND-DATE.30m. Each time that your project has been observed, you can download your data by doing:

scp xxx-yy@gra-lx1.iram.es:~/observationData/mira/*.30m .

9. Can I change my observing strategy or requirements during the pool ?
• YES, OF COURSE ! Every time that your project is observed, you will be asked to download your data (see point 8). If you want to modify your strategy taking into account your remaining time, etc... you have only to update your README file in the poolw-12 account (check point 7).
10. Do I have to enter my observing procedures in the Heterodyne pool account ?
• No. You have to create your own procedures and your README file, and send them to the pool manager, Manuel Gonzalez (gonzalez@iram.es), who will check them, and will include them in the poolw-13 account. He will let you know if there is something wrong.

11. How do I do to get the passwords to the herapool and the project (xxx-yy) accounts ?
• For security reasons we cannot send this information via Internet. If you want to know the passwords, please, contact the pool manager, or phone to the telescope (00 34 958 48 20 02) and ask it to the operator or the AoD.
12. Who pays the trip and the stay at the telescope of the pool astronomers ?
• For astronomers from the IRAM member states France, Germany and Spain, the expenses for travel and subsistence will be paid by IRAM according to the usual funding rules. Astronomers from other countries will have to pay for their flights, but subsistence and lodging at the telescope is paid by IRAM (as well as a room in IRAM's downtown residencia, depending on your flight schedule).
13. Who can help me to prepare my procedures ?
• If you have problems with preparing the procedures, or if you have any other doubt concerning the Heterodyne pool, please, contact the Heterodyne pool manager, Manuel Gonzalez (gonzalez@iram.es)

## Checklist for project start

* Check the calibrations for each receiver/backend combination, and for each pixel (either on ODP screen, or with MIRA). MIRA issues a warning if something goes wrong.

* Check that CLASS files are correctly written (into /vis/xxx-yy/observationData/mira/*.30m).

* When you start the execution of an observing procedure provided by a pool PI, make sure that you are on the right source (we recommend to select the source in the script, but this is not always done if several sources are to be observed with the same script).

* If you need the wobbler, ask the operator to switch it on. When a wobbler switch observation starts, please check the wobbler signal on the {\it wobbler monitor} mounted below the ceiling, in front of you.

* If you use frequency switching, have a look at the oscilloscope to the left of the operator's desk.The LO signal needs to jump with the same phase time entered into PaKo.

## A few caveats

* Try to reach the receiver temperatures published in the HERA manual (Figure 2, page 5), at http://www.iram.es/IRAMES/otherDocuments/manuals/index.html. As an indication: at 230.5~GHz, the receiver temperatures of the HERA1 pixels
are typically between 100 and 150 K, and for HERA2 between 150 and 200 K, respectively. For some pixels this will not be possible.

* The derotator may run into its limits during a project, due to the parallactic rotation and its corresponding tracking in the receiver cabin. Once you obtain the first scan XXX of the source to be mapped (typically a
calibration), please use MIRA and type

scan XXX
view /derotator [positionAngle]

where positionAngle is the HERA position angle on the sky (typically 9.5 degree for the oversampled mode, and 18.5 degree for the undersampled mode). If you do not specify it, its value is taken from the scan header. If part of
the curve shown is red, you will have to change the HERA position angle to its value +- 90 degree. The time at which you will have to do this is shown on the plot.

* After a telescope slew of 50 degree and more in Azimuth, please do the pointing twice. Even if the first one looks good, the pointing parameters may change meanwhile due to the update of the inclinometer values.

## Observing templates

### Templates for project startup:

Setup.pako general parameters and defines catalogues

Sourcecat.sou a template source catalogue

### Templates for observing (HERA):

heraLinecat.lin A template line catalogue for HERA.

heraBackend.pako Defines backends and connects them to the receivers.

heraPointing.pako Sets the derotator to position 0 frame, connects the continuum backends, does a pointing (beam switch, calibration optional), and reconnects the spectrometers.

heraFocus.pako Sets the derotator to position 0 frame, connects the continuum backends, does a focus, and reconnects the spectrometers.

heraOnOff.pako Observing mode: on-off. Switch mode: total power. Is usually called position switch.

heraWobbler.pako Observing mode: on-off. Switch mode: wobbler.

heraFrequSwitch.pako Observing mode: track. Switch mode: frequency switching.

heraOnTheFly.pako Observing mode: on-the-fly. Switch mode: total power.

heraOnTheFlyFrequSwitch.pako Observing mode: on-the-fly. Switch mode: frequency switching.

### Utility GREG procedures for OTF preparation:

simulateOS.greg GREG simulation of HERA's oversampled mapping mode (outputs PAKO command line).

simulateUS.greg Same for HERA's undersampled mapping mode.

### Templates for observing (EMIR):

EmirLinecat.lin A template line catalogue for EMIR.

emirBackend.pako Defines backends and connects them to the receivers.

emirPointing.pako Connects the continuum backends, does a pointing (beam switch, caliabration optional), and reconnects the spectrometers.

emirFocus.pako Connects the continuum backends, does a focus, and reconnects the spectrometers.

emirOnOff.pako Observing mode: on-off. Switch mode: total power. Is usually called position switch.

emirWobbler.pako Observing mode: on-off. Switch mode: wobbler.

emirFrequSwitch.pako Observing mode: track. Switch mode: frequency switching.

emirOnTheFly.pako Observing mode: on-the-fly. Switch mode: total power.

emirOnTheFlyFrequSwitch.pako Observing mode: on-the-fly. Switch mode: frequency switching.

www.iram.es mainWiki: HeraObserving (last edited 2013-12-04 17:18:03 by ManuelGonzalez)

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