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For each Cycle, a long-term schedule (LTS) is generated which includes all observations for the current cycle. These include targets assigned to specific weeks, plus targets assigned to a Pool. In Cycle 2 there are several pools, one general pool from which a target may be taken at any time and 3 others which will primarily used to fill the few months prior to their position in the LTS.
The final, planned schedule for each week is the short-term schedule (STS), which is posted on the public web once approved for upload. The STS includes all observations within that week from the LTS plus additional targets from the pool. The LTS is updated each week to incorporate the actual scheduling to date.
Here we provide a brief description of the observation planning process
including key timescales and deadlines of which observers should be aware.
Due to the increased constraints on scheduling observations on Chandra, we
will be scheduling Cycle 7 targets to be observed along with Cycle 6 effective
imediately. We expect the completion of Cycle 6 targets to occur in February
2006. Please note that we are unable to provide funding for the early Cycle 7
observations until the Cost proposal review is completed in November.Early scheduling of Cycle 7 and extension of Cycle 6
User Support for Observation Planning
Each Chandra observation is assigned an uplink support scientist from the DOSS or Calibration groups at the CXC based upon the selected instrument. The uplink scientist is responsible for contacting each observer to confirm their observation configuration in advance of releasing the observation for scheduling on the satellite.
The process includes a series of steps:
When a scheduled observation is not actually done; e.g., due to radiation, safe mode, TOO, or other unforeseen circumstances.
The CXC (uplink support scientist) contacts the PI/observer of each
observation to confirm their observing parameters in advance of
the selection of their target for the STS.
It is crucial that ALL PIs/observers (GO/GTO/CAL/TOO alike) respond to
this contact and adhere to the deadlines requested by their contact. Observations with no GO
confirmation will not be scheduled, sometimes resulting in a delay of
a year before the observation is possible again.
| Action | Timing (days before 1st day of week being scheduled) |
| First Contact with GO |
|
| Response required | 32 days before first day of week being scheduled |
| OBSCAT is finalized internally | 25 days |
| Observation request is submitted for scheduling | 23 days |
A generic form of the current contact letters and information can be found at one of the following links:
This is generated for each observing cycle. It places about 50% of the targets into one week bins, taking note of all observing constraints. In order to achieve an efficient final schedule, the remaining unconstrained targets are placed in the pool and are selected for observation by the Mission Planning team as they become visible to Chandra.
The LTS is updated weekly as each STS is generated and is available on the LTS page. Pool targets, which are those most likely to move around, are labeled clearly in each schedule.
The Cycle 2 LTS is currently being prepared. It has four pools
allowing observers an improved estimate of when their observation may
be scheduled during the year. The pools targets are listed in weeks
in January, May and September with a general pool (pool 4), also in
September. Targets in this latter pool can be selected for observation
at any time during the year while the other three pool targets will primarily
be selected during the 4 months prior to the listed week.
Short Term Schedule (STS)
This is generated weekly in preparation for upload to Chandra on the Sunday
of that week. It is also posted on the public web at that time. This is
the official observation plan but we note that unanticipated events, such as
TOOs, increased solar activity, satellite problems etc., can interupt the
schedule resulting in some of the observations not being completed.
In this case, an updated STS is generated and posted on the web and affected
observers are notified. Click here for a link to
the current STS.
Target Pages
Each target has a set of pages which provide information on the planned observation. This includes a general page, with the proposal abstract, PI and general target information, links to DSS (Digitized Sky Survey) and ROSAT (if available) field-of-view (FoV) overlays appropriate for the middle of the week in which the target is placed in the LTS and a detailed list of all observation parameters. Observers are encouraged to review these pages to confirm the observation setup well in advance of the observation date and either submit changes or else confirm that the configuration is correct to their uplink contact scientist.
Once a target is placed in an STS week, the FoV overlays are updated to the
actual roll angle for the scheduled observation time and date.
Last modified: 09/26/05
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Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA. Email: cxcweb@head.cfa.harvard.edu Smithsonian Institution, Copyright © 1998-2004. All rights reserved. |