Notes from Project Management Meeting, Durham 12/6/97
wht-naomi-89
Internal Document Number:
AOW/MAN/AJL/16.2/06/97/Costs-9798 allocations meeting
Document version date: 18 June 1997
Original date: 13 June 1997
Present: ABG, RAH,
AJL, RMM, JMDS, MW
The following are brief
notes. The goal of the meeting was to (a) confirm allocations for 1997/98 (b) identify areas where additional
allocation / rephasing can bring the project forward (c) look at areas where
further cost savings can be made if necessary.
AJL stressed how much project
delay was driving up costs via overheads. Every effort must be made to keep on
schedule.
(a) Profiles as presented in Excel sheet were acceptable.
(b) ROE might be able to
bring work forward if extra electronics engineering effort is found.
(c) Ideas were roughly prioritised as follows, with approximate level
of saving being given, if known. Scale:
1 = don’t consider further at present
to 5 = will implement pending
final confirmation from Project Engineer.
Other decisions which were
made during the discussion are given first.
1. Run two EPICS
databases - cost slightly more up-front but could save later. Therefore RGO to
develop own electronics rack
2. Put high priority on getting interface documents set
up, so different WPs can proceed as independently as possible.
3. Choose two 4-port CCD controllers option rather than
one 8-port. Reasons: no extra
development work over other systems being delivered; assurance that timing between CCDs is issue already being
handled; compatibility with other
spares.
4. Don’t adopt
options which significantly restrict off-axis capability - we’d look too much
like ELECTRA.
5. Use of same bay for RGO and ROE electronics rack mountings still preferred if possible). Need more information on total electronics
requirements before finalising this decision.
Items 1 - 5 above are to
be implemented on the issue of version 16.2 of this document.
It should be assumed that
items at level 5 in the list below will be implemented, pending final
confirmation from the Project Engineer and a subsequent check with ING where
there are any performance or reliability issues. formal confirmation of
implementation will be given ‘soon’
Items at level 4 require
further discussion, which should be organised during the week of 16th June by
those named. However, it should not be
assumed that they will adopted until these discussions have taken place.
Items at level 3 and lower
will not be adopted but for levels 2 and 3 they will be noted for
reconsideration should further savings be required. Items at level 1 and 0 are unlikely to be reconsidered for cuts.
|
Don't cool chip. 2 - 4K |
3.0K |
- quantify first. (ABG is
doing this) |
5 |
|
Have only 1 filter
wheel |
3.8K |
recoverable - space will be
left for second wheel. |
5 |
|
Slightly reduce
time/T&S level of support for CRJ.
|
10K |
Practical given CRJ’s other
commitments |
5 |
|
Omit sidereal tracking
option implementation - expect small saving |
~2K |
Can be implemented later at
no overall increased cost |
5 |
|
Don’t implement brakes
option on carriages, use holding current
|
10K |
ABG to discuss with AW, RAH
and omit brakes brakes if both engineers are satisfied with holding current
concept from stability and thermal viewpoints. |
4+ |
|
Complete engineering
(stand-alone) software only |
Up to 100K |
Discuss with Guy. Run
integrated software as separate strand of project. (~ 0.5 dsy = £22K
identified as sensible cut which would still give good functionality) |
4 |
|
No encoders, use step
counting |
10K |
Saving much less if
facility still has to be designed in
Also tied to power down option.
Keep encoders on pick-off x-y at least. The ‘4’ mark is for
non-pick-off encoders being omitted. Do the 3 WFS elements need
to occupy space that could be occupied by one of the other elements. i.e. can
the pickoff run into the collimator? If so then care must be taken when
powering up from an unknown state and moving to datums. |
? 4 |
|
Take out on the fly change
of waveforms |
4.5K |
note: requires reboot of
CCD controller for each change |
3 |
|
N.C.U. omitted/delayed |
55K |
RGO WFS cal unit placed
at Nasmyth focus (optics may be slightly over f/11). Knock
on effects are poor for operation. Know we'd have to make NCU eventually So eventually. that whole WFS
cal unit does not have to be replaced/removed for each calibration it would
probably be sensible for the final mirror of the cal unit to be a manual flip
in mirror. |
2 |
|
Don't implement second
chip |
24K |
Requires 4-port controller
then solve timing later. Hits badly on latency esp in 4cell mode |
2 |
|
No WFS calibration source - do all with NCU |
7.5K |
|
2 |
|
Tip-tilt option in NCU -
delay or cut? |
? |
|
2? |
|
No ADC |
9.2K |
Lose funadamental high
Strehl performance |
1 |
|
WFS on-axis only - remove
xy pick off |
?? |
Lose too much sky cover and
main gain over ELECTRA |
0 |
|
Don’t use EPICs
|
?? |
|
0 |
|
Don't even write s/w control for OMC |
?? |
|
0 |
|
Dispense with DM height
control |
?? |
Too large an effect on
alignment, observational off-axis performance. |
0 |
The Durham grant has a figure of
£100K for the new DM and its electronics. Over half this is the
electronics. A potential saving of ~£35K
might be found if the ELECTRA mirror drivers can be modified to cope with the
higher capacitances of the Xinetics mirror actuators. This avenue should be
pursued, following up on the indication from Xinetics that they might let us
have an individual actuator for testing.
Some small saving might be
made by omitting implementation of the sidereal tracking option, but an amount
was not identified.
1. Savings likely
to be adopted (marking 5 and 4+) £28.8K
2. Possible
saving on continuous face-sheet DM electronics £35.0K
3. Delayed spend
through phased software approach, ~0.5 d.s.y. £22.0K
4. Next level of
saving priorities (to marking 3) £14.5K
5. Have
engineering level software control + phase A study only £55.0K