Cluster BM3 allocation during 2016 dayside
orbits
Inroduction
This page describes the implementation of BM3
dumps for the period
when the Cluster apogee is in the magnetosheath
or solar wind between November 2015 and June 2016.
Requirements
A BM3 dump is required twice per orbit.
EFW will use BM3 to dump very
high-resolution data.
BM3 scheduling should have minimum impact on
other scientific data-taking.
BM3 scheduling should not signficantly add
to the complexity of operation preparation.
In particular it should be straightforward to insert a baseline
set of BM3 periods into the MSP template.
Proposed implementation
The requirements above can be satisfied by
scheduling BM3 dumps near perigee and apogee.
The apogee case is straightforward so we deal
with that first. The perigee case is much more
tricky because of the complexity of operations
in that region.
Apogee case
In this case JSOC proposes to schedule the
BM3 dump at apogee. This may occasionally
conflict with some other operation, e.g. solar
wind BM1, WBD period, or no-data-taking period. In these cases JSOC will
resolve the conflict by moving the BM3 dumps by
a few hours (forward or backward as
appropriate).
Perigee case
The period within a few hours of perigee will be restricted by eclipses
(when the payloads are switched off) during parts of this period
and will be the target of science observations, e.g. auroral acceleration region studies or Guest Investigator
proposals, WBD periods, away from eclipses.
We have therefore continued the perigee strategy with BM3 4 hours before perigee throughout the period.
This will be adjusted on a case-by-case basis to deliver the best science targeting and to match payload off times ahead of eclipses. There are a few periods around perigee when a GI proposal requests NM1, and in these cases, the BM3 will be moved before the start of the WBD period (which may be more than 4 hours earlier).
See the Bryant plot for the 2016 dayside constellation.
Implementation in MSP template
Starting with this constellation, the baseline set of BM3 periods is tied to a new set of events (type 3B) that are inserted
when we generate the events file (msp_planning.txt) used to construct the new template. These events are inserted at 4 hours before
C1 perigee and at C1 apogee, but with the 3B event times rounded to nearest minute. This greatly simplifies the task of constructing
the baseline BM3 periods.
Last updated by Mike Hapgood ( mike.hapgood@stfc.ac.uk), and
Helen Walker ( helen.walker@stfc.ac.uk),
27 August 2015
|
