How to do service observations using the OB Queue

General description
OB accounting
OB Queue detailed help

General description

First of all it would be good to carefully read the general idea behind the service observing programme as described on our web-pages and the more detailed description of how to define the observations in a set of Observing Blocks using the OB Generator.

The main purpose of the OB Queue interface is to provide an easy way to select Groups of OBs that can be observed. OBs that have to be executed in one night (e.g., one OB for an object and one OB for a standard star) are grouped together. The Groups are the basic building blocks that define the observations to be done in a night. Per definition a Group of OBs is only successfully executed if all OBs in a Group have been observed in the same night.

Apart for the instrument selection (currently only either ALFOSC or NOTCam, where StanCam and FIES are always a valid option as they can be used at all times), the main selection criterion that can be used to plan observations is the range in LST. This range in LST is used to select all the Groups that have a total execution time less or equal to the total time between the start and end of the range _and_ for which all the OBs in the Group can be executed within the range in LST. In this way one can get an overview of which Groups of OBs could be observed during a night and one can make an observing plan for the night, where one should aim to execute the highest ranged proposals if at all possible, which defines the instrument set-up that is likely needed during the night. This still requires to check in a bit more detail the requirements for the different OBs included in each Group, but at least it should make planning easier. Furthermore, it is also possible at any time to provide a smaller range in LST with any number of other constrains such as seeing or weather. I.e., if the weather changes during the night it should be simple to see which Groups of OBs can still be observed considering the weather and the amount of time left.

It is important to realize that the user interface is only meant as a tool to help you select and plan the observations, and you still should look at the specific requirements (some of which might only be defined in the `comments') for each OB.

After having selected a Group of OBs for execution you can look at the details of the OB which will include one or more observing scripts to execute with specific set-ups. The scripts are located under the scripts directory of the observers account, for instance ~obs/scripts/51-009/ and follow the naming convention <groupID>_<blockID>. The entire content of the directory is shown on the OB detail page. If an observing script of a given OB is not present in the directory, it is necessary to compile the script from the information stored in the OB Generator. This is done by pressing the button 'Compile OB' on the OB details page.

When an OB has been attempted the status should be changed to 'Completed' or `Failed', depending on if the requirements for execution of the OB were met or not, and you can add any comments under `Progress' (e.g., if anything special occurred during the execution of the observations). Also comments can be added for a Group (by clicking on the name of a Group), e.g., when only part of a Group could be executed because the weather changed. Please note that these comments are (the only thing) sent to the PIs of the proposal so try to be as clear as possible.

Every day the system will check the data base and look for OBs that have been attempted. If all the OBs in a Group are 'Completed' the Group will be closed and the PI notified. If only part of the OBs in a Group have been executed, all the OBs will be reset to 'Active' as the Group is considered not to be complete. The PI is still notified as s/he might find the data still of some use. Note that this implies that OBs and Groups can contain comments from previous attempts.

IMPORTANT The one remaining issue are calibrations. Any night time calibrations such as arc exposures for spectra should be defined in OBs by the PIs of the service proposals. However, daytime or twilight calibrations (such as dome or twilight flat fields for imaging, or calibration lamp flat fields or arc exposures for spectroscopy) should be provided by the service observer her/himself.

Before the observations

• At the top of the main page, enter the known constraints for the night you are going to observe. These could be Moon phase, instrument, and LST range. You can look in more detail at requested observations by clicking on the individual `Group Names'. This will show general information about the Group, including links to the individual OBs and links to other Groups of the same proposal. It is always good to have a look at the OBs to see if there are any special requirements which might affect planning the observations.
• REMEMBER! All OBs contained in one Group have to be executed during the same night!
• The proposal can also be viewed by clicking the proposal number listed under Proposal ID in the main page. Have a look at the proposal for some background. Note that the description of the observations in the proposal might be different from that defined in the OBs. At all times, the description as defined in the OBs is the one you should execute.
• If you click on the name of an OB you get a complete overview of the requirements for the observations defined in it. Here the target name is given together with its coordinates. The Sequences lists the details of the individual exposures. Comments concern the OB are useful, and must be read. Also, any comments on previous attempts of executing the OB might be found here under `Progress'.
• If you have selected some Observing Groups you can get an overview of all the OBs involved by going to the `Groups view' and select the Groups by clicking the radio button at the start of each line. Clicking `Show Blocks' at the bottom of the page will show all OBs included in the various Groups in one overview. This gives the most direct overview of the observations for the night as you can order the OBs by various parameters which might help you to plan the observations (e.g., ordering them by RA will give you the most obvious order in time in which to execute the OBs, or ordering by instrument, let's say ALFOSC and FIES, will allow you to minimize changing instrument during the night by grouping the observations with the same instrument together) and/or might help you decide which Observing Groups you can fit together within a night. This option can also be very useful when the weather changes during a night.
  Note that when using `Show Blocks' there is an option to 'Show visibility plot for today' of all targets in the different blocks that were select. The sources in the visibility plot will be numbered in the way the blocks are ordered. It is also possible to check the selection of OBs against the current instrument setup at the telescope. This is very useful in order to plan the change of filters etc. needed to be able to observe the selected OBs
• Calibrations:For any instrument set-up that is used during the night calibration observations should be provided. For imaging with ALFOSC this should be twilight flat fields (or dome flat fields if sky flat fields can not be taken, e.g., due to the weather. For narrow-band filters dome flat fields should be good in all cases).
  

  For spectroscopy with ALFOSC day time flat field and arc spectra should be provided if not specifically request as part of the night time exposures (especially in the red, people will ask for flat fields to be take during the night when the telescope is pointing at their target to be able to correct better for fringing). In principle, a single arc spectrum with the same set-up as used during the night (i.e., the same slit and grism) should be sufficient and a set of at least 5 flat fields should be taken. For the arc spectra some care should be taken with not saturating the arc lines too much (a mildly saturated line is no big problem) and for the flat fields the maximum counts in a flat field should not exceed ~40,000 ADU. In general it is more practical to only obtain these calibration after the observing night when it is clear which precise instrument and CCD settings have been used for the observations.
  

  One thing to remember with the calibration exposures is to use the same CCD settings (binning and windowing) as used for the science exposures. Also, BIAS frames should be provided with the same CCD setting.
  

  For NOTCam basically the same guide lines apply, but for the details of the calibration observations follow the specific instruction given on the NOTCam pages.
  

  Note: All calibration observations are written to one directory for all service proposals, and one should set the rempath to /data/service/calib when doing any daytime/twilight calibration.
  

DURING observations

• Remember to take bias frames before the night starts.
• During twilight remember to take the requested number of flats in all bands that are planned to be used that night.
• Observe all OBs in one Group the same night.
• Check the comments in the OB before execution.
• Execute the Observing Script of the OB. If it does not exist, create it via the 'Compile OB' button.
• When the observations for an OB have finished:
  • The Status should be set to 'Completed' if the conditions during the observations (seeing, clouds, etc) met the defined requirements for the OB
  • If the conditions during the observations do not meet the requirements, e.g., the seeing gets worse or clouds moved in, the Status should be set to 'Failed'
  • In all cases, provide any relevant comments about the observations in the Progress field.
• When all OBs of an Observing Group are 'Completed' you can also add (general) comments to the Group.
• Note that the comments you add to the OBs and Group are the only comments that the PI will see about the execution of the observations, so please try to be clear and informative.

In the morning

• Do any remaining twilight or daytime calibrations
• Check that all calibration frames were put in /data/service/calib/. If rempath was not set correctly at any one time you can just copy the images here.

OB accounting

When an OB has been attempted the status should be changed to 'Completed' or 'Failed', depending on if the requirements for execution of the OB were met or not, and you can add any comments under `Progress' (e.g., if anything special occurred during the execution of the observations). Also comments can be added for a Group (by clicking on the name of a Group), e.g., when only part of a Group could be executed because the weather changed. Please note that these comments are (the only thing) sent to the PIs of the proposal so try to be as clear as possible.

Every day the system's OB-janitor will check the data base and look for OBs that have been attempted. If all the OBs in a Group are 'Completed' the Group will be closed and the PI notified. If only part of the OBs in a Group have been executed all the OBs will be reset to 'Active' as the Group is considered not to be completed successfully. The PI is still notified as s/he might find the data still of some use. Note that this implies that OBs and Groups can contain comments from previous attempts.

OB level

• For every OB that you attempt, update the OB-status to 'Failed' or 'Completed' .
  • The Status should be set to 'Completed' if the conditions during the observations (seeing, clouds, etc) met the defined requirements for the OB
  • If the conditions during the observations do not meet the requirements, e.g., the seeing gets worse or clouds moved in, the Status should be set to 'Failed'
• If an OB in an OB-group does not have to be done, for instance as it has already been done as part of another OB-group, mark that OB as 'Redundant' .

OB-group level

• For every mutually exclusive pair of orange OB-groups, for instance Slit_1.0 vs Slit_1.3 groups, mark one of two mutually exclusive OB-groups as 'Redundant', also when the weather is bad.
• For every remaining orange OB-group, that is not already in 'Attempted' state (green) on the main Queue page, please mark at least one of the OBs as 'Failed' or 'Completed', also when the weather is bad ('Failed').

OB Queue detailed help

This is the most important page when doing service observations. From here you search for eligible observing groups and make a list of the groups and corresponding blocks you wish to execute.

Search Interface:
The search interface allows you to query the database containing the observing groups by defining constraints. The interface consists of the following elements:

• Identifier:
  If given either a specific proposal number or group name, only that will appear in the output of the search.


• The Night:
  Specify the observing date, the meteological conditions of the night of service observations, the start and end time of observations and the instrument mounted at cassegrain. Observing conditions of a group will at least have to comply to these criteria. For instance:
  - If the seeing is 1.2", any groups specifying a seeing of 1.2" or better will be selected
  - If the night is clear, any groups specifying clear or thin cloud conditions will be selected
  - If the moon is Dark, any group will do (requires dark,grey or bright)
  - If the instrument mounted is ALFOSC, groups requiring NOTCAM will not be selected
  - If you plan to do service observations in what corresponds to a LST range between 16 and 18, all blocks belonging to one group must be observable in this period. If only one block falls outside, the group is rejected. Also, in this example the total time requested for a group must be less than (18-16)=2 hours. Valid LST range: 00 - 23 Default date is today. You can filter time critical groups for another date by entering this.


• Group Properties:
  Allows you to further limit the search result by constraining properties of the group: Status and maximum time requested. Finally, you have the option to set the order of the search result.

Search Result

The groups matching the search criteria are listed in a table, ordered as requested above. The fields being output corresponds to the properties of the group which in many cases are derived from the individual blocks. The fields are:
- Proposal ID: The Proposal ID identifier. The link gives access to the proposal details (see below)
- Group Name: Name of the observing group. The link gives access to the group details (see below)
- Instrument: The instruments used in all OBs in the group. This can be more than one, however never ALFOSC and NOTCAM together. - Mode: Observing Modes (imaging, spectroscopy, etc.) used in the OBs. - Optical Elements: Optical elements (filters,grisms,etc.) that are needed to successfully observe all OBs in the group. - Seeing: The best seeing condition found among the blocks of the group.
- Weather: The most constraining weather condition found among the blocks of the group
- Moon: The most constraining moon phase found among the blocks of the group
- Obstime: The total observing time, calculated as the sum of the individual observing times of the blocks.
- OBs: The two numbers represent the number of blocks that have been observed and the total number of blocks making up the group, respectively.
- Pri: The priority of the group, as decided by the PI.
- Rat: The rating of the proposal, as decided by the OPC.
- Link: Indicated whether the group is linked to another group.
- Status: The status of a group can be any of three:
  --- 'Active': The group is still to be executed.
  --- 'Attempted': One or more blocks have been executed. The following morning the status will automatically be set to either 'Active' or 'Closed'.
  --- 'Closed': All blocks in the group have been observed.

Colors: Rows can have colors to help sorting out matters:
  --- Green: One or more OBs belonging to this group has been 'Completed' or marked 'Failed'.
  --- Orange: Time critical group that will expire in the morning after the specified date of observations.
  --- Yellow: Time critical group that can be observed on the specified date of observations.

There is the option of selecting one or more groups for creating a list of all corresponding blocks by using the check-boxes to the left of the list with the search results. To create the list, click the button marked 'Show Blocks'.

Block List

Following the procedure described above, you can create a list of observing blocks that a) follows the selection criteria you have specified and b) insures a consistent choice of OBs that leaves no group half-done. This is the preferred way of creating a a list of observing blocks for a given night. It is possible to re-arrange the list of OBs by clicking in the table headers. This way, the list can for instance be ordered by seeing or start LST. For each block there is a link leading to a detailed view of the OB (see below).

Colors: Rows can have colors to help sorting out matters:
  --- Green: This OB has been 'Completed'.
  --- Orange: This OB has been marked as 'Failed'.

Group Properties

Following the link 'Group Name' in the search result leads to a page with a detailed description of that particular observing group. The description includes details of the proposal, like PI and Title, a list of other groups belonging to the same proposal, group properties and comments and finally a detailed list of the observing blocks making up this group. The purpose of making comments to the group is to allow for comments concerning the execution of the group as a whole. For instance a reason if not all blocks were observed during the night.

Block Properties

A link to the OB properties is given both on the Group Properties page and the Block List page. Apart from the OB details, this page lists all the Observing Sequences that makes up the OB. An important aspect of this page is the information provided on the Observing scripts and the option of on-the-fly compilation of scripts. You have the option of making comments on the execution of the OB in the text-box labelled 'Progress'. Finally, once the OB has been observed you will need to change the status of the OB from 'Active' to either 'Completed' or 'Failed'. If you know the requirements of the OB was not fulfilled, set status to 'Failed'. Otherwise, set status to 'Completed'. The system will automatically update the status and properties of the group, send an email notification the the PI and other administrative tasks.

On the proposals page is listed a summary of all active and past service proposals. Information includes PI name and origin, program title, requested observing time and rating. Furthermore, the observed and total number of observing groups and blocks are shown to give an idea of the current status of the proposal; If for instance the Groups read '2/2' it means that no groups are left to be observed. Following the link 'Proposal Number' leads to a full description of the proposal, including the technical and scientific assessments. Certain information, like meteological data or exposure times, are also found in the observing blocks. There are no check on whether the PI inserts the same values in the OB as found in the proposal (i.e. the observing block might require a max seeing of 0.7", whereas the proposal says 1.0"). In case of differences, always use the values in the OB. In principle, to carry out service observations there is no need to read through the proposals. However, you might find information that could help you determining the quality of the data obtained.