Aladin Phase 1 FAQ

General:

  1. How do I change the plotted aperture?

    The APERTURE field in the Aladin Information section can be used to change the displayed aperture. The selection available is limited by the choice of DETECTOR (and by the use of a simplified list...see next item), which defaults to the first detector used in the Instrument Setup.

  2. Why are there only a limited set of apertures?

    In order to keep Phase I as simple as possible, we have limited the number of apertures available for display in Aladin (the complete suite is available in Phase II mode). For STIS, the 50CCD/25MAMA imaging apertures are displayed, the 0.2X0.2 Echelle aperture is used, and the 52X2 longslit is used for first-order observations.

  3. How do I see coordinated parallel observations?

    To set up a coordinated parallel, you need to select the Coordinated Parallel flag for the parallel observations, and you need to link that Parallel to the Prime in the Aladin Information area of the Prime observation. To view both observations in Aladin, you need to multi-select the two Observations in the APT Tree Editor.

  4. What is the Aladin Orientation Angle field?

    This is the orientation angle that is presently displayed in Aladin (note that the field is not populated until Aladin is brought up). It initializes to either 0 (if no ORIENT has been specified in the proposal) or the middle of the range if an ORIENT range is specified. This value is strictly a display value, so if you rotate an aperture in Aladin to determine an acceptable ORIENTation range for your observation, you will need to type the range you determine into the Scheduling Requirements area of the Observation.

  5. What is the Mosaic Tile container?

    For non-mosaic observations, there is one object (Tile 0) listed. This can be used to change the color of the aperture in Aladin. For mosaics, there are multiple entries, one for each tile in the mosaic. Besides changing color, the offset location of the tile (in POS TARG values from the nominal target) is given.

Mosaic:

  1. How do I make a mosaic?

    To make a mosaic, you specify the size of the mosaic using the Mosaic Size fields, as well as the desired tile overlap (which defaults to 10%). Note that if you have linked a coordinated parallel to the mosaic, the parallel will automatically pick up the mosaic details.

  2. How do I add/delete tiles from a mosaic?

    To add a single tile, use the Add Tile button. This will place the tile on the edge of the existing mosaic (see the next item for how to move the tile into its desired position). To delete a single tile, open the Observation container and the Mosaic Tiles container. Select the tile you wish to delete in the Tree Editor, and delete it (using the Delete command in the Edit Menu). Note that with the tile selected in the Tree Editor, you can look in Aladin to confirm it is the tile you wish to delete. To add or delete a new row or column, change the values in the Mosaic Size field(s).

  3. How do I move an individual tile of a mosaic?

    To move a tile, you must select the Create POS TARGs mode in the Aladin panel in APT (the screen you see in APT when you select the "View in Aladin" tool). In this mode, you can move tiles around individually. If this mode is not selected, moving one tile will cause all tiles to move the same amount (since they are linked as part of the mosaic).

  4. How do I determine the correspondence between the tile number in the Tree Editor and tile in the Aladin display?

    There are four ways to do this. The easiest way is to turn on Labels in Aladin, which will label each aperture with the Observation and Tile numbers. You can also open the Observation and Mosaic Tiles containers, and select an individual tile to display in Aladin. You can also examine the POS TARG values in the individual tiles. Finally, you can use the Aladin Tree to disable individual tiles (by left clicking on the tile) - the Aladin Exp number tells you the tile number in the APT Tree.