General principles of Phase 2 (PH2)

Purpose of PH2

Technical notes

• PH2 is compatible with most browsers. Due to the recent prolific development of browsers on several platforms, we cannot support all of them.
• Except for one optional tool, PH2 does not include any Java code. It is entirely developed around JavaScript and the ColdFusion language.
• Some of the information entered during Phase 1 (Title, Abstract, contact information) is automatically transferred to PH2.
• Target information can be entered quickly in PH2 by uploading a specifically formatted ASCII file.
• There is a time-out of 2 hour for inactivity periods (that is, between "save" activations). A window reminds the user of this 2 minutes before the expiration of the session. Save your work frequently! If you cannot access PH2 due to this but immediately must do so, send us an email and we will correct the situation.
• To ensure data integrity, only one session with the same user ID is allowed at a time.
• During the Phase 2 period, you can access PH2 at all time and as many times as you want. All your work is saved in the database so you do not have to finish everything at once... Also, there is no "submit" button: when you're satisfied with the preparation of your observations (for instance, what you see in your program summary), that's all there is to it!
• PH2 allows the observations of moving targets (e.g. Solar System objects) by entering targets ephemeris. Non-sidereal tracking or non-sidereal guiding are offered on some instruments only. Due to the telescope's limitations, tracking without guiding is only good for less than about 2-3 minutes. If you select the non-sidereal tracking option, please keep your individual exposures under that length. Please also note that:
  • At least 3 sets of RA and Dec coordinate pairs must be entered, enough to cover the potential time of observation. The times are in UT.
  • Non-sidereal tracking will fail if there is not at least one time before and one time after the time of observation.
  • The sets must be spaced far enough apart in time to cover the longest observation.
  Programs with moving targets can be complex so do not hesitate to contact us during the preparation of your observations.
• It is possible to define "user dithering patterns" for the imagers in PH2. However, this practice is not recommended because it can result in severe difficulties during the data reduction. Only use the nonstandard dithering patterns when necessary, or if you are already very familiar with data analysis.
• Due to some difficulties in tracking the sizing activity applied to a browser window from PH2, we recommend that you size PH2 to the maximum allowed by your screen at the beginning of the session (before logging in) and keep it that way. All the necessary scroll bars have been implemented for navigating within the browser frames.

PH2 interface

You can change the size of all the frames inside PH2 by dragging their side with the mouse.

• Navigation Menu: The left frame is a navigation menu, with buttons for the different sections of PH2. The button corresponding to the current section goes from blue to white. Quick Help Files and a Tutorial are available from the bottom buttons.
• Top Frame: If present, it either displays non-editable content (e.g. list of target names) or selectable options.
• Middle Frame: This frame presents the tables for the targets, instrument configurations, constraints, etc. The maximum number of rows displayed at once is usually 5, but buttons allow the user to navigate through different pages inside this frame. At the bottom of each table, a series of buttons allow the addition, duplication, deletion, or selection of rows. The purpose of each button is explained by placing the mouse over them.
• Bottom Frame: This frame includes the buttons for saving the data to the database, cancelling changes, and a help button. Placing the mouse over each button makes a short description appear. When the "Save" or "Proceed" buttons are pressed, the information is automatically saved in the database.

The concept of Observation Groups -- Observation Groups (OGs) are the entities selected from the database, put in the queues, and executed at the telescope by the Service Observer. This subsection explains which entities make an OG.

The entire architecture of PH2 and its database is based on the concept of Observation Blocks (OB); each OB is made of one (and only one) target, one (or many) instrumental configurations, and one (and only one) set of constraints. Each target, configuration or constraint is a unique entity and has a unique label. A target, configuration, and set of constraints may be used more than once, to define various OBs and OGs. Since it is easier to schedule short observations at the telescope, there is a limit of 2 hours (7200 seconds) for the total integration time of one individual observation block.

1. Targets can have fixed coordinates (Fixed Targets, or FT), or coordinates defined by ephemeris (Ephemeris Targets, or ET). For each instrument, tools are available to bring up finding charts and refine the pointing or the identification of the target.
2. An Instrument Configuration (IC) consists of a filter, exposure time, and dithering pattern (for an imager), or an observing mode, exposure time, and Stokes parameter (for ESPaDOnS). An IC can be used in more than one OB and OG, so there is no need to duplicate identical ICs.
3. Constraints concern the desired Image Quality, sky background level, and airmass range. A set of constraints can be used more than once, so there is no need to duplicate identical sets.

An OB is simply created by picking one target, one or more ICs (for example, an IC for a red filter plus an IC for a blue filter; or the IC for Stokes Q and the IC for Stokes U), and one set of constraints.

To add more flexibility to PH2, the concept of Observation Groups (OG) has been introduced. The interface to prepare the groups is illustrated below. Three different types of OGs are available, as illustrated below:

• Single OB (1OB): One OG is made up of 1 OB. If all OGs are of this type, they can all be created quickly by using the button "Quick Create OG" button.
• Sequence (SOB): It is possible to create a sequence of OBs, and link different OBs (or the same OB!) that should be executed successively, under the same constraint. An SOB can include different targets, but due to the additional overheads introduced, this is not recommended unless necessary.
• Monitoring (MOB): If an OB must be observed several times with a regular period, a monitoring OG including this OB can be defined, using a period, a number of iterations, and a minimum number of iterations acceptable.

Each OG can have a comment, which will appear when the database is queried. These comments are extremely helpful, and can include specific additional constraints or repeat information found elsewhere in PH2 (e.g.: "Observe at -1hr < HA < +1hr"; "<0.3mag extinction for this target", "Follow with OG34"; "Double star, pick faint one"; "Observe May 3rd only").

As each OG is created, the remaining I-time is calculated. If you exceed your allocated I-time, you will not be able to save your latest changes.

PI-defined calibrations

Summary

Contact information