Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Date of circulation:8 May 2008
ECSS Working Group: ECSS-E-60-10 WG
Deadline for reply: 4Juy 2008
WG convenor: P. Laurens (Astrium Satellites)
DRRs received from ECSS members
The Working Group is requested to disposition all the DRRs coming from ECSS members and in case of “Rejection” or
“Acceptance with modification” contact the DRR-originator to inform him about the proposed DRR disposition.
ECSS TA member
Date of reply
Number of DRRs
ECSS registration no.
D. Baum (DLR)
07.07.2008
No comments
-
IN/2008-70
F. Durand-Carrier (CNES)
07.07.2008
No comments
-
IN/2008-69
F. Felici (ESA)
04.07.2008
79 DRRs
001 to 079-ESA
IN/2008-68
R. Formaro (ASI)
No reply
I. Gibson (BNSC)
No reply
G.D. Meijvogel (NIVR)
No reply
Eurospace
08.07.2008
10.07.2008
13 DRRs
10 DRRs
080 to 092-Eurospace
093 to 102-Eurospace
IN/2008-71
IN/2008-72
Remarks: None
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------DRRs reveived from non-ECSS members
The WG is requested to disposition the DRRs but has not the obligation to inform the DRR-originator about the proposed disposition.
Originator of DRR
Total DRRs received
DRR received
-
Number of DRRs
-
-
ECSS registration no.
-
102 DRRs
Remarks: Draft 2.6 (distributed on 14 May 2008) contained 3 corrections to Draft 2.5 (distributed on 8 May). Corrections are
indicated on front sheet of Draft 2.6.
Page 1 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
001-ESA
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
N/A
N/A
A. Benoit
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
It was expected to withdraw the ESA Pointing Error
Handbook when this new E60-10A standard is made
applicable.
7. Proposed change
Recommend to TA a way forward based on the
WG experience (if appropriate, add some text to
the standard):
8. Disposition of
DRR
9. DRR
implemented
A
- complementary material for pointing error
budgets will be found/added in the E60-10H
handbook
- new ECSS WG will be settled focussing on
pointing errors (unlikely)
- each entity (ESA, national agencies, primes) can
further elaborate internal documents, deriving
appropriate guidelines and summation rules from
this E60-10A standard
 Agreed. In the short term, see the notes added to §1 (scope).
002-ESA
Different messages are spread over the draft, and let the
reader in an uncomfortable situation:
A. Benoit
4.2.3
Note 8
9
“Alternative summation rules can be found in the
literature (…./…)They are therefore not recommended.
Annex A.2.1 discusses this further.”
29,3
0
(about PDF convolution)”This is impractical except in the
very simplest cases: what is instead required is a simple
rule to estimate the distribution of the total error so that is
can be compared to the requirement.” “In such cases
more exact methods are recommended, though the
approximate techniques used here are still useful for an
initial rough assessment.”
A.2.1
A.2.3
32
It is understood that the WG convenor or members
rejected the option to endorse/recommend
simplified summation rules in a general context. It
is not understood if the proposed approach is
realistic or not.
A
Can you wrap up the present messages spread in
these different sections in one stand alone section
and also explain clearly which rules are applied in
the worked examples of the Annex, and what are
the limitations and possible way forward.
Note that the summation rules given above are not the
only ones that can be found in the literature. In particular,
the approach adopted by the ESA pointing error
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 2 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
handbook was to classify errors according to their time
periods (Short term, long term, systematic) and use a
different way to sum between classes. This was an
attempt to make the summation rules more conservative,
and such rules have worked well in practice, but there is
no mathematical justification for such approaches, and
they can overestimate the overall variance if the inputs
have been estimated well.
 This discussion is (briefly indeed) hold in section 4.2.1, warning for the limitation of the approach and mentioning the fact that engineering judgement is required to assess the
pertinence of the budgeting rules, and the limitations of the budgeting approach in general. It seems difficult to be more specific in the limits of a standard (examples could be
developed in the handbook to support this discussion, if needed).
The rules used to work out the budgets in Annex C have been made explicit (link to the method from clause 4.2, and to the formulas from clause 4.2.3).
003-ESA
F.Affaitati
3.2.6,
3.2.7,
10,
17
4.2.2.3
Mean Knowledge Error, Mean Performance Error: the
term “mean” is also used to characterise the distribution
of probability of the error.
It is proposed to use the term “mean” for the
statistical description and the term “average” for
the estimation over a time interval.
R
 Agreed on the principle, but the ambiguity is thought minor enough not to reword the standard
004-ESA
C.3
F.Affaitati
005-ESA
F.Affaitati
4.
43
…(20 arcsec about x and 1 arcmin about y).
…(20 arcsec about y and 1 arcmin about x).
44
Table C-3: (arcmin)
(arcsec)
In some cases the error ε(t) evolves with some degree of
continuity over the time. This assumption in the statistical
framework is missing.
The concept of random walk (Wiener Process)
should be introduced as a possible reference
model for the error.
This assumption is important to describe the a-posteriori
probability of an error ε(t+δt) once ε(t) is known.
Independent errors would be described by the same
probability density
This allows the characterisation of the error in
terms of random walk standard deviation.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
A
done
R
See below
Page 3 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
ε(t)
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
ε(t+δt)
t
A correlation in (delta)time, would shape the a-posteriori
probability differently:
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 4 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
ε(t)
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
ε(t+δt)
t
A good example is the angle error in a gyro when the
rate sensor is used to track the angle changes.
 Your proposition is well understood. Note that in the standard there is no restrictive hypothesis on the statistical nature of the error signals (not necessarily ergodic, or even
stationary) so this category of random walk (or more general unsteady signals) is encompassed by the rules we propose.
More generally we agree that there would be room to be more didactic and complete on the statistical framework and the error statistical models and properties. Unfortunately this
would require some rework we cannot do in practice seen the delay to issue the first version. This is to keep in mind for a next version of the standard (as well as some other
recommendations from other DRRs, such as 065-ESA for example).
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 5 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
006-ESA
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
All
D. Fertin
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
The title of the document is not sufficiently informative
and some paragraph titles are not correct.
1.
Change the title to “performance and
stability: requirements and assessment”?
R
1.
The document is called control performance
whereas it addresses also stability
2.
Rename paragraph 4 “Performance
requirements and budgeting”.
A
2.
Paragraph 4 is called “performance analysis
methods” whereas it addresses performance
requirement and performance budgeting.
9. DRR
implemented
done
 For convenience we propose to keep the title of the standard unchanged. In some extended sense (defined in the handbook, not published yet) the “stability” properties can be
understood as an intrinsic performance indicator for a control system.
007-ESA
N/A
N/A
The document address performance requirement and
budgeting but not performance verification. I fear that this
might be interpreted as “a nice budget is enough to verify
performance”
Add a comment or a clause explaining that a
performance budget must be confirmed by an
appropriate detailed simulation campaign using
Monte-Carlo techniques or worst-case simulation
scenario.
N/A
N/A
Pointing stability requirements are not addressed in the
document.
Address pointing stability.
D. Fertin
008-ESA
D. Fertin
A
Note added to
4.2.1
 Pointing stability can be managed using the appropriate indicators (RPE), although we recognise the standard in its current version is not exhaustive from this point of view.
please see also 063-ESA.
009-ESA
3.1
10
D. Fertin
010-ESA
3.2.1
10
First phrase is incomplete:
I suggest to explicitly mention:
“For the purpose of this Standard, the terms and
definitions from ECSS-P-001B apply, in particular for the
following terms:
3.79 Error,
xxx”
3.216 uncertainty
The definition of knowledge is only done in annex, this is
not facilitating the reading of the document.
I suggest using hyperlink inside the document for
all references such as for example the reference to
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
A
done
3.145 performance,
R
Page 6 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
annex A.1.3.
D. Fertin
 There is already an active link to the annex A.1.3 in the document. Note that the definition of knowledge is given in §3 (3.2.5). A.1.3 does not give the definition, just some rules on
how to set knowledge requirements.
011-ESA
D. Fertin
3.2.14 &
3.2.15
The definition of robustness appears twice and is not
correct as robustness does not mean anything alone: a
control system is either robustly performant or robustly
stable.
I propose to replace by the following:
A
done
A
done
A
Agreed, note 5
modified
“ability of a controlled system to maintain some
performance or stability characteristics in the
presence of plant, sensors, actuators and/or
environmental uncertainties.
NOTE 1: Performance robustness is the ability to
maintain performance in the presence of defined
bounded uncertainties.
NOTE 2: Stability robustness is the ability to
maintain stability in the presence of defined
bounded uncertainties.”
012-ESA
4.2.2.1
17
Rather than “All error sources contributing to the budget
shall be listed, including the sources considered
negligible” which mean having to update and track
negligible contributors during the entire life of the project.
I would prefer: “All significant error source contributing to
the budget shall be listed. A justification for neglecting
some potential contributors should be maintained in the
error budget report document.”
4.2.3
18
The rule of note 5 is obviously rigorously wrong for
correlated errors or at least not general: correlation can
be positive if error contributors are opposite (I have at
least a case).
D. Fertin
013-ESA
D. Fertin
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
I would prefer a note clarifying that this is a bound
and that effect of correlation must be investigated.
Page 7 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
014-ESA
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
6. Review deficiency and justification
7. Proposed change
4.2.4.2.2
20
The second mu is again mu_A instead of muB in the first
bullet
5.1
21
In the introductory paragraph there is a confusion
between robustness characteristics of a controlled
system and uncertainties: “For an active system, it is
often of major interest for the customer to have quantified
knowledge of the robustness, in order to identify
accurately the boundaries of the safe operating domain,
and also to be able to specify it to the contractor in
charge of the control development.”
I would replace by:
In many places of the document, the word customer and
contractor are used without defining what is the product
being bought or contracted therefore introducing an
ambiguity totally unnecessary (see proposed
corrections).
Remove all references to customer and contractor
(see proposal for each of them below)
D. Fertin
015-ESA
Proposed dispositions approved by TA on: ___________________
D. Fertin
016-ESA
5.1
21
D. Fertin
5.2.1.1
22
5.2.1.2
22
5.2.1.3
8. Disposition of
DRR
9. DRR
implemented
A
done
A
done
A
done
“For an active system, a quantified knowledge of
uncertainties within the system enables to:

Design a better control coping with actual
uncertainties,

identify the worst case performance
criteria or stability margins of a given
controller design and the actual values of
uncertain parameters leading to this
worst case.
In practice:
1.
the controlled system hardware and software can be
contracted to the same company (for example:
AOCS done by the prime),
2.
the controlled system software and hardware can be
contracted to two different companies
3.
the control software is designed by a company
subcontracting the hardware.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 8 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
4.
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
the controlled hardware is designed by a company
subcontracting the control software.
For example, in clause 5.2.1.1 it is said “an uncertainty
domain shall be defined by the customer” however as
uncertainties are mainly related to the hardware, in the
framework 3 defined above the contractor should define
the uncertainty
017-ESA
5.1
21
Remove unnecessary use of contractor and customer to
keep this standard at a technical level.
It is intended to help to formulate clear
unambiguous requirements in an appropriate
manner, and the contractor to understand what is
necessary with no risk of ambiguity.
A
done
5.2.1.1
22
Remove unnecessary use of contractor and customer to
keep this standard at a technical level.
An uncertainty domain shall be defined identifying
the set of physical parameters of the system over
which the stability property is going to be verified.
A
done
5.2.2
23
The sub-clauses impose to assess the stability over an
uncertainty domain; this can only be done by some
analysis techniques and not tested. Therefore, to raise
confidence in the results, they should be verified with
another analysis. In control engineering, linear stability
analysis results can typically be verified by time
simulation.
I would add two subclauses to this clause:
A
done
D. Fertin
018-ESA
D. Fertin
019-ESA
D. Fertin
020-ESA
e. The stability condition shall be verified by
detailed time simulation of the controlled
system.
5.2.3
22
Remove unnecessary use of contractor and customer to
keep this standard at a technical level.
Checkpoints shall be identified according to the
nature and the structure of the uncertainties
affecting the control system
A
done
5.2.4 d
23
Remove unnecessary use of contractor and customer to
keep this standard at a technical level.
The appropriate stability margin indicators shall be
identified and justified by the control designer
according to the nature and structure of the
A
done
D. Fertin
021-ESA
d. The point of the uncertainty domain leading to
worst case stability should be identified.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 9 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
uncertainties affecting the system.
D. Fertin
022-ESA
N/A
N/A
D. Fertin
023-ESA
3.2.3
10
J-P. Lejault
In order to design a controller adapted to the
uncertainties affecting the system, I would propose to
add a clause to require not only to specify the value of
uncertainties on parameter but also the reason for
uncertainties.
The error index is not clear. The understanding is that it
can be an attitude, a rate, or whatever else.
Or is it a APE, AKE, MKE, MPE defined in the same
section but before or after
Uncertainties could be due to:

lack of characterisation of the system
parameter (for example: solar array
flexible mode characteristics assessed by
analysis only),

intrinsic error of the system parameter
measurement (for example: measurement
error of dry mass)

change in the system parameter over the
life of the system,

lack of characterisation of a particular
model of a known product type.
Complement the definition and add examples or
introduce first Error index (instead of 3.2.3) not
following alphabetic order in 3.2 but hierarchical
and logical order
A
Clause and
note added as
suggested
(§5.2.1.1)
AM
See below
 Clarification given in NOTE 3. Alphabetical presentation is the ECSS rule for this definition section
024-ESA
3.2.6
11
Typo
In NOTE 1, replace MME by MKE.
A
done
025-ESA
3.2.8
11
done
3.2.11
12
Add a note in 3.2.8 and 3.2.11 stating that the time
intervals t1 and t2 are in a single observation
period.
A
J-P. Lejault
The PDE and PRE have the same mathematical
definitions, but correspond to different usage. This does
not come clear until reading the table B-1 p.35.
J-P. Lejault
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 10 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
026-ESA
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
3.2.10
12
The definition of “performance knowledge error” is a pure
duplication of “knowledge error”. Besides, the term
“performance knowledge error” is only used in 3.2.4.
Use either “performance knowledge error” or
“knowledge error”.
A
Done (3.2.10
useless,
removed)
3.2.12
12
Typo
In NOTE 1, replace RME by RKE.
A
done
4.1.4.2
16
An example would be useful to better grab the statistical
interpretation.
Add an example.
R
Please confirm and make clearer in the section
4.2.2.2
R
J-P. Lejault
027-ESA
Proposed dispositions approved by TA on: ___________________
J-P. Lejault
028-ESA
J-P. Lejault
 This seems to be appropriately covered by annex A.1.2 (link given in the note of 4.1.4.2)
029-ESA
4.2.2.2.
17
J-P. Lejault
It is my understanding that groups of errors contain
errors which are uncorrelated.
 DRR not understood. The presentation and wording of the clauses a, b, c, and d seem clear enough. In particular clause c states that “all errors which can potentially be correlated
with each other shall be classified in the same group”
030-ESA
4.2.2.3
17
The NOTE 3 is not understood (last sentence
incomplete)
Please correct NOTE 3.
A
4.2.3
18
(Editorial) The section would be easier to read if the
notes were appearing just below the items “a” to “d” to
which they refer.
Please consider re-arranging the notes.
R
J-P. Lejault
031-ESA
J-P. Lejault
done
 May well be, but it seems that putting normative clauses together – then notes – is an ECSS drafting rule (TBC; minor anyway)
032-ESA
J-P. Lejault
4.2.4.2.1
20
It is not clear whether the errors eA and eB are
independent.
Add clarification.
A
See below
Better justify the statement in NOTE 1 that this condition
is extremely conservative.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 11 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
 Clarification added; see example of numeric application in annex A.2.4 (note).
033-ESA
4.2.4.2.
20
Definition of Log unclear.
J-P. Lejault
A.2.4
33
Definition of log unclear (w/o block initial)
034-ESA
5.2.1.1
22
Examples are missing to better show what an uncertainty
domain is.
J-P. Lejault
Make clear that this logarithm refers to the natural
logarithm (base e) (result of computation involving
the cumulative function of the Rayleigh distribution)
A
Add examples.
AM
The definition of the reduced uncertainty domain is not
stated explicitly. This can lead to various interpretations,
and this should be avoided.
Define the “reduced uncertainty domain”, and give
examples.
AM
The wording “the system operates nominally” is not clear.
What does “nominal” mean”? Here again, it is important
to state this clearly to avoid various interpretations when
using the standard.
Define the nominal operations, and give examples.
done
 Note 5 added for clarification in 5.2.1.1, already modified and completed after 022-ESA
035-ESA
5.2.1.2
22
J-P. Lejault
 Introductory text and figure added p. 23 to illustrate the concept and the underlying idea.
036-ESA
5.2.1.3
22
J-P. Lejault
The definition of the extended uncertainty domain is not
stated explicitly. This can lead to various interpretations,
and this should be avoided.
Define the “extended uncertainty domain”, and
give examples.
What does “safely” mean in this context? This might also
be not consistent with other ECSS standards in which
the notion of safety is defined.
Define what is meant by “the system operates
safely”, and give examples.
Check the consistency with other ECSS standards
related to safety and remove the word “safely” if
there is an inconsistency.
AM
 Introductory text and figure added p. 23 to illustrate the concept and the underlying idea.
037-ESA
5.2.2.b
23
The word “restricted” probably refers to “reduced”, as
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Replace “restricted” by “reduced” for consistency
A
done
Page 12 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
J-P. Lejault
038-ESA
5.2.3
23
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
spelled out in 5.2.1.2.
purposes.
Checkpoints are not sufficiently defined.
Add a definition of checkpoints and give examples
in Note 1 or before
J-P. Lejault
8. Disposition of
DRR
9. DRR
implemented
 Notes 1 and 2 appear sufficiently clear for the purpose of the standard, considering that this concept is relevant to basic control engineering skills (mainly for MIMO or nested
loops). If required some more detail or illustration could be added to the handbook.
039-ESA
5.2.4.d
23
The wording “different indicators” is confusing. It can
mean several indicators, but it probably means indicators
different from the ones identified in items a, b and c. If
this is the right interpretation, then “other indicators”
avoids the confusion.
Replace “different indicators” by “other indicators”
A
5.2.5
24
In the item a.4, the peak sensitivity should be defined. An
example should be given.
Define “peak sensitivity” and give an example.
R
In the item a.4, the complementary sensitivity should be
called “peak complementary sensitivity” and it should be
defined and an example given.
Define “peak complementary sensitivity” and give
an example.
J-P. Lejault
040-ESA
J-P. Lejault
done
 Considered as control engineering academic knowledge, no need to redefine in this standard.
041-ESA
5.2.6
24
The wording “nominal stability” is ambiguous.
Also “Simple” uncertainty domain appears in the title for
the first time.
The wordings “nominal stability” and “degraded stability”
are ambiguous. They should be clearly defined.
Define the nominal and degraded stability terms,
and define or replace ‘”simple”.
Better explain if there is a one-to-one
correspondence between “nominal” resp.
“degraded “stability and “reduced” resp.
“extended” uncertainry domains introduced in
previous section 5.2.1
A
Precisions
given in 5.2.6
and 5.2.7
26
What does “TF-PF” on the Y axis stand for on Fig A-1
and A-2?
Clarify this
A
Done
(removed)
J-P. Lejault
5.2.7
042-ESA
J-P. Lejault
A.1.1
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 13 of 25
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10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
043-ESA
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
A.1.2
26
The “statistical ensemble” is called “imaginary ensemble”
in the ECSS-E-60-20A-Draft6.7(22November2007).
The terminology between both standards needs to
be made consistent.
A.1.2
B.1
27
34
There is a partial commonality between the definition of
the 3 possible statistical interpretations (ensemble /
temporal / mixed) and the annex E.2 in the ECSS-E-6020A-Draft6.7
Modify either this draft or recommend adequate
modification of the Star Tracker standard.
J-P. Lejault
8. Disposition of
DRR
A
9. DRR
implemented
See below
 The term “statistical ensemble” seems more standard – see Wiki: “in mathematical physics, especially as introduced into statistical mechanics and thermodynamics by J. Willard Gibbs in
1878, a statistical ensemble is an idealization consisting of a large number of mental copies (sometimes infinitely many) of a system, considered all at once, each of which represents a
possible state that the real system might be in”.
No conflict seen between the 2 standards concerning the ensemble / temporal / mixed interpretations.
044-ESA
A.1.2
27
J-P. Lejault
B-3
36
The text refers to “the 3 limits”. This is not consistent
with 4.1.4.1.b which excludes references to n-sigma
values.
The statement “Using the 3 bound” is not consistent
with 4.1.4.1.b which excludes references to n-sigma
values.
045-ESA
Solve the inconsistency.
A
See other ESA DRR against 4.1.4.1. which
recommends not to forbid 3terminology and
proposes to rewrite 4.1.4.1 b as
“probability specification shall be preferred over nsigma. N-sigma specification shall be used if
Gaussian distribution can be assumed for the
budget”.
Clarify.
???
OK, see DRR
060-ESA
J-P. Lejault
046-ESA
A.1.4
28
The NOTE is not a note, but an example.
Change to EXAMPLE.
A
done
A.1.4
28
In the paragraph following the NOTE, RPE should be
replaced by PRE to make sense.
Replace RPE by PRE
A
done
29
After the paragraph “When specifying requirements…”, in
J-P. Lejault
047-ESA
J-P. Lejault
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 14 of 25
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10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
the first 2 bullets, RPE should be replaced by PRE
048-ESA
A.1.4
29
The text states “It is also possible to define the PRE
index without an explicit reference to a timescale”. This is
not compatible with the definition of the PRE given in
section 3.2.11.
Explain.
A
Clarification
note added to
A.1.4
A.2.3
31
The last but one section p.31 makes the difference
between the 68% percentile and the 1-sigma value. The
theoretical rationale is understood. However, the
approach is based on the central limit theorem, meaning
that a Gaussian distribution is expected. Therefore, the
68% percentile and 1-sigma level should be equivalent.
Better explain.
A
Clarification
added
J-P. Lejault
049-ESA
J-P. Lejault
 The difference between the sigma and the 68% is for the individual contributing errors, and not for the total sum (which tends to Gaussian from the CLT). Clarification added in the
standard.
050-ESA
A.2.4
32
Typo in the section paragraph line 5
complaint to be replaced by compliant
A
done
A.2.4
32
It could be useful to remind the reader with the
connection between nP sigma levels and percentiles for
Gaussian distributions: 1 sigma = 68%, 2 sigmas = 95%
and 3 sigmas = 99.7%.
Consider adding the clarification.
A
Done
(additional
note)
A.2.4
33
“The RPE of the directional error angle is zero”. The
actual RPE value depends on the integration time to
compute the RPE. The assumption here is that the
integration time is equal to the nutation period.
Clarify.
R
J-P. Lejault
051-ESA
J-P. Lejault
052-ESA
J-P. Lejault
 In this simplified example (given to support the discussion) the nutation motion is conic then the “directional angle” is constant (half-cone angle) and the associated RPE is zero
whatever the period.
053-ESA
A.2.4
33
In the last paragraph, the factor 2.83 is not introduced
mathematically.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Explain how this numerical value is computed.
A
Precision
added to A.2.4
Page 15 of 25
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10.07.2008
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4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
J-P. Lejault
054-ESA
B.2
35
In table B-2, the meaning of “S.I.” , “E”, “T” and “M” is
unclear. It is probably “statistical interpretation”
,“Ensemble”, “Temporal” and “Mixed”. There is no SI in
the acronym list p. 14.
Clarify. This also applies to various tables in the
annex B.
A
done
B-4
37
“The ensemble parameter A” appears in B-4 and B-5.
Does “A” stand for periodic errors?
Clarify.
A
done
B.6
39
The meaning of A, B, C and s is unclear.
Clarify.
A
Done in the
text
C.3
43
The compilation of the pointing budgets is a very
important section in the standard. However, there are no
details at all on how the tables C-3 and C-4 are derived
from the table C-2. The tutorial aspect is important here,
and a few key links should be established between the
source (table C-2) and the budgets (tables C-3 and C-4).
Explain the way the budgets are derived from the
ensemble parameters. Give the detailed
computations for a representative selection of the
key cases.
R
See below
J-P. Lejault
055-ESA
J-P. Lejault
056-ESA
J-P. Lejault
057-ESA
J-P. Lejault
 For each contributor the link to the formula used in tables of annex B is given. It’s hard to be more explicit and we don’t really see the need to develop further here.
058-ESA
R. Jansson
5.2.4
23
SISO system stability requirements require to also use
modulus margin. This may not be in line with industry
preferred design methodologies, which are equally
suitable.
Do not drive industry to use a specific design
methodology.
As for SISO systems, the MIMO system stability
requirements require sensitivity and complementary
sensitivity functions. Many times, MIMO systems can be
sufficiently decoupled and treated as SISO systems,
allowing more classical design methods. Industry should
have the possibility to use their preferred method if
Change text to allow industry to use their preferred
method with proper justification.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
R
Page 16 of 25
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10.07.2008
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4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
properly justified.
 We fully agree with this concern. Please note that the clauses a and b only define default methods. Clauses c and d open the door to alternative methods, provided they are duly
justified by the contractor. The standard is already in agreement with your proposition.
059-ESA
D. Temperanza
3.2
3.3
1014
3.2.5
11
The abbreviated terms and acronyms are different from
the ESA Pointing Error handbook introducing confusion
with the previous notation and meaning. For example
APE that before was “absolute pointing error” is now
“absolute performance error” AME is now AKE, etc
Note 2 says “sometimes confusingly referred as
measurement error” and seems to condemn the
utilisation of AME
Provide an explicit reference and link with the
current terminology: Absolute Pointing Error and
Absolute Measurement Error used in pointing error
specification and budgets.
A
Explain more clearly that AKE is based on
estimators using different sensors measurements
and even evolution models.
Let pointing error applications free to keep AME as
a daughter of AKE ?
 A specific annex D has been added with a correspondence table to facilitate the transition.
060-ESA
D. Temperanza
4.1.4.1
16
The statement “The n-sigma notation for expressing
probabilites shall not be used” conflict with many other
current or past ESA project where such notation is in
place. In addition it conflict with para 4.2.2.1 of the
present doc where this notation is also used.
Change clause a and b:
“Probability specification shall be preferred over nsigma. N-sigma specification shall be used if
Gaussian distribution can be assumed for the
budget”.
A
done
We could additionally remind that upon certain
condition are verified the assumption of Gaussian
distribution is not to be excluded a priory.
The central limit theorem (CLT) states that the sum
of a large number of independent and identicallydistributed random variables will be approximately
normally distributed.
 4.1.4.1 has been modified according to your suggestion.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 17 of 25
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10.07.2008
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4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
061-ESA
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
A.2.3
31
D. Temperanza
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
The formula for the total variance in matricial forms is not
fully correct.
7. Proposed change
It would be better to express the variance not as a
vector but as covariance matrix and to use the
correct matricial formulation
8. Disposition of
DRR
9. DRR
implemented
A
done
[Sig^2] = Sum ( T [sig_i^2] T^-1 ),
see Wertz formula (12-74) page 12.3
See also formula 12-72b for the mu term.
062-ESA
Table B-3
36
There is a reference to a Table B-3, but the table is
missing.
Introduce the table.
A
done
B-4
37
About distinction between short and long term periodic
errors : it is not clear short and long with which respect.
It would be good to add a reference to a very good
JPL paper building the relationship between RPE
and periodic disturb over frequency.
A
done
D. Temperanza
063-ESA
D. Temperanza
The reference is “New Definition of Pointing
Stability: AC and DC effects” Lucke,Sirlin, San
Martin. The Journal of the Astronautical Sciences
Vol.40 No.4 Oct Dec 1992 pp 557-576.
Note similar approaches are already in use in
industry.
064-ESA
S. Salehi
Transformation of semi-cone requirement to 2-axis
requirement and back.
This item is not addressed explicitly. Often equipment
(including payloads and many sensors) are specified with
semi-cone pointing requirement, whereas the spacecraft
bus is usually specified with 3-axis pointing requirement.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Please include requirements on (forward and
backward) transformations between semi-cone
and 3-axis pointing requirements.
Please include an example describing the issues
involved.
Page 18 of 25
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10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
The conversion or transformation between the two
approaches is not addressed.
Practical rules of thumb may not be mathematically
hyper-rigorous but very useful.
 In the general case (quadratic combination of two errors), this issue is addressed by 4.2.4.2 and annex A2.4.
065-ESA
N/A
N/A
S. Salehi
Pointing requirements for spinning spacecraft.
The whole issue of spinning spacecraft is not addressed.
For example, this problem came up for Plancke, where
pointing requirements had to be derived from scratch.
Please include requirements on spinning
spacecraft pointing requirements.
R
Please include an example describing the issues
involved.
 Indeed this would be a valuable input for the AOCS application of the standard, unfortunately we have the problem that the standard aims at covering general control systems, the
spinning case being highly pointing-specific. This conflict being keeping general and going in detail for AOCS needs was a major source of difficulties for the working group, and this
is reflected by several DRR (see 001-ESA, 008-ESA, 066-ESA, 070-ESA for example). See also notes added to §1 (scope).
In the short term, the planning for issuing the Standard version 1 is to tight to take your comment into account. In the medium term, a workaround solution must be put in place to
focus on pointing issues (and in particular on spinning spacecraft), as suggested by 001-ESA.
066-ESA
S. Salehi
N/A
N/A
The standard appears to address only individual 3-axis
spacecraft, whereas the title is “Control Performance”.
Missing aspects include, at least, the following:
-
thermal control
-
robotics, rovers and mechanisms
-
spacecraft formation flying (a new area, still to be
charted?)
-
ground spacecraft test facility control systems (e.g.
hydraulic or E-M shakers, etc.)
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Please justify exclusion of the named topics, else
include control performance requirements for
them.
R
Page 19 of 25
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10.07.2008
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4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
-
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
multiple spacecraft, e.g.
-
separation (launcher payload release,
spacecraft probe release,
-
joining (rendezvous, docking, capture)
-
etc.
 We agree that most examples and illustrations are oriented to SC pointing issues, due to the context and the people involved in the working group. Nevertheless the main body
of the standard, the definitions and clauses are as general as possible, and have been made in such a way that they apply to any type of control systems, as given in your list. This
applicability is introduced in the scope (§1) of the standard.
067-ESA
N/A
N/A
S. Salehi
Frequency domain pointing performance requirements
are missing.
Please justify exclusion of the named topic, else
include control performance requirements for it.
 As for 065-ESA, this is a good suggestion. In practice, end-to-end performance requirements set in frequency domain are not so frequent. Most of the case they are given in time
domain over given timeframes (possibly several off), which can be managed using the RPE/RKE indicators for example. Nevertheless we agree that introducing PSD requirements
should be considered in a next version of this standard.
Also note that the question is addressed in the handbook (not fully ready for publication yet).
068-ESA
S. Bennani
069-ESA
G. Gienger
Section
3.2.17
13
Definition is imprecise / parameters describing the
system should be better reworded / what are the
parameters?
Provide a definition that is precise and that is
general
A
Introducti
on
7
Note:
Please add the associated handbook as a
reference and make it available.
AD
“nor in the associated handbook.”
Example
added to
§3.2.17
 This will be done as soon as the handbook has been upgraded for publication. The planning is still TBD.
070-ESA
G. Gienger
1
8
Document states
“The standard defines a general framework for handling
performance indicators, which applies to all disciplines
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Add explanatory paragraphs and some not
pointing-related examples.
R
Change
Page 20 of 25
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10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
involving control engineering, and which can be declined
as well at different levels ranging from equipment to
system level.”
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
Declined -> defined
A
Expand xxx
A
done
Done
(preliminary
note in section
3.2)
However it appears that section 3 ff. are mainly dealing
with satellite pointing and measurement errors.
 See 066-ESA
071-ESA
3.1
10
G. Gienger
072-ESA
xxx
3.2
10
Unclear if document is dealing with scalar, vector,
attitude or other multi-dimensional quantities/errors
Add a clarification sentence.
A
3.2
10
A definition of the absolute error is missing. This may
lead to confusion about the sign of the errors.
Add definitions, e.g.
R
G. Gienger
073-ESA
G. Gienger
In particular for the following terms:
Absolute error= measured quantity – true value
(usual definition, but sometimes the opposite
convention is used)
Absolute attitude error = measurement of attitude
matrix times transpose of true attitude matrix
(following Malcolm Shuster)
On p. 25 some definitions are given, which may be
moved to here:
“For spacecraft pointing errors, the indices usually
are specified in terms of the Euler angles ε
(between the target and actual payload frames) or
ξ (between the actual and estimated payload
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 21 of 25
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4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
frames).”
 This is deliberate in the sense that the application of the standard does not depend on the convention used to define the error signals (and in particular the sign). See also new
preliminary note added at beginning of section 3.2 (from DRR 072-ESA)
074-ESA
4.1.1
15
075-ESA
4.1.4.1
16
G. Gienger
4.2.4.1
2,5 arcmin
Change to 2.5 arcmin
A
done
Change minus sign to proper multiplication sign
(or no sign as per 1)
A
done
G. Gienger
4.2.4.2.1
19
20
076-ESA
A.1.2
26
“Depending on the exact scenario, {A} could include such
things as the physical properties of the spacecraft,
sensor biases, orbit, and so on:”
In the first place, the control error depends on the
design of the controller. So this should be listed
first.
A
done
A.1.2
28
Figure A-5 caption too long for list of figures
Suggest to cut caption after 0-10.
A
done
Equations
1-5
3032
Editorial
“Equation i” use different font sizes
Use same font size
A
done
C-1
41
Figure C-1 is depicting an unrealistic configuration:
The solar panels need to be nearly perpendicular to the
Sun. Therefore either the star tracker or the payload
points also towards the Sun.
Suggest to rotate the solar panels by 90 degree
around Z-axis
A
done
3.2.6
11
Clerical error in NOTE 1.
Replace MME by MKE.
A
done
G. Gienger
077-ESA
G. Gienger
078-ESA
G. Gienger
079-ESA
G. Gienger
080-Eurospace
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 22 of 25
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4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
081-Eurospace
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
3.2.9
12
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
As for knowledge, definition of performance error should
be introduced before definitions of mean performance
error.
7. Proposed change
8. Disposition of
DRR
Advance section 3.2.9, and introduce it just after
section 3.2.6.
R
9. DRR
implemented
 Agreed, but the ECSS rule for the “definitions” section seems to be alphabetical.
082-Eurospace
3.2.10
12
Introduction of “performance knowledge error” is
misleading. Up to that point “peformance” and
“knowledge” were associated to 2 different things.
Remove section 3.2.10.
A
done
083-Eurospace
3.2.11
12
Definition of “performance reproducibility error” is the
same as the one of “performance drift error” even if they
are proposed to be used with different time scale in
between deltaT1 and deltaT2.
Remove section 3.2.11 and eventually add a note
in 3.2.8 saying that the performance drift error can
be used as a reproducibility index.
A
See 025-ESA
084-Eurospace
3.2.1,
3.2.6 and
3.2.12
Requirements related to the knowledge of the
performance are called “XXX Knowledge Error” with the
associated acronysm “XKE”, as “Measurement” is the
usual name in ESA Pointing Error Handbook.
Harmonize in changing “Knowledge” by
“Measurement”.
 The point is precisely that we propose to switch from “measurement” to “knowledge” which is more appropriate in a general situation. This is an evolution with respect to the old Pointing
Error Handbook. See also the new annex D that should be helpful.
085-Eurospace
3.2.11
12
086-Eurospace
Clerical error in NOTE 1.
Replace PDE by PRE.
A
Instantaneous knowledge error and instantaneous
performance error are used several times as they have
been defined through absolute knowledge error and
absolute performance error.
Replace “instantaneous knowledge error” and
“instantaneous performance error” by “absolute
knowledge error” and “absolute performance
error”.
R
done
 This is true, but in the context where these “instantaneous” terms appear (in the definition section, §3) this avoids to refer to the APE/AKE definition (very minor point anyway).
087-Eurospace
3.2.12
12
Clerical error in NOTE 1.
Replace RME by RKE.
A
088-Eurospace
3.2.14
13
“Robustness” definition calls for the stability notion as
“stability” is defined after.
Shift section 3.2.14 after section 3.2.16.
R
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
done
Page 23 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
 Agreed, but the ECSS rule for the “definitions” section seems to be alphabetical.
089-Eurospace
3.2.16
13
Stability margins do not address systematically all
parameters of the system.
Replace “…excursion of the parameters
decribing…” by “…excursion of some parameters
decribing…”
A
done
090-Eurospace
4.1.2 and
4.1.3
15
and
16.
The 2 sections are not clear. 4.1.2 is supposed to
address “performance” and in NOTE1 some of the
indices relates to “knowledge” ; and 4.1.3 which is
supposed to adress “knowledge” refers to 4.1.2 which is
supposed to adress “performance”.
Clarify.
A
Clarified.
091-Eurospace
5.2.4
23
Point a. addresses gain, phase and modulus margins as
stabillity criterion, but definitions are not provided.
Include definitions of gain, phase and modulus
margins.
R
 Considered as control engineering academic knowledge, no need to redefine in this standard.
092-Eurospace
5.2.4
23
Point b. addresses sensitivity and complementary
sensitivity functions as default indicators, but definitions
are not provided.
Include definitions of sensitivity and
complementary sensitivity functions.
R
 Considered as control engineering academic knowledge, no need to redefine in this standard.
093-Eurospace
3.1
10
An unexpected “xxx” sentence remains
A
done
094-Eurospace
3.2.6
11
The expression shall be noted MKE instead of MME
(mean knowledge error)
A
done
095-Eurospace
3.2.11
12
The expression shall be noted PRE instead of PDE
(performance reproducibility error)
A
done
096-Eurospace
3.2.12
12
The expression shall be noted RKE instead of RME
(relative knowledge error)
A
done
097-Eurospace
5
21
It could useful to add clauses about notions of bandwidth
characterization, mode rejection, controller damping and
R
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 24 of 25
Compiled DRRs from Public Review of ECSS-E-60-10A Draft 2.5(2.6)
10.07.2008
Dispositions of DRRs done by Working Group on: ________________
4. Review Item no.
(Entered by Secretariat)
DRR number - Originator
5. Location of
deficiency
clause
page
(e.g. 3.1
14)
Proposed dispositions approved by TA on: ___________________
6. Review deficiency and justification
7. Proposed change
8. Disposition of
DRR
9. DRR
implemented
noise transmission, which are also some performance
indicators
 This is true, but in practice, these indicators are used internally by the control engineers to design, tune, characterise and validate the control laws. They are not “final”
performance indicators for which they are formally specified by the customer. Considering this, we have decided not to include them in this standard.
098-Eurospace
B
3435
It would be helpful to recall notations (E=ensemble /
T=temporal/M=mixed, µ = mean /  = variance, …)
A
done
099-Eurospace
B.6
39
The delta-function should be added in Table B-7 for
illustration (e.g. to easily compute the table C-2)
A
done
100-Eurospace
C-3
44
The unit is arcsec (not arcmin)
A
done
101-Eurospace
C-4
44
The unit is arcsec (not arcmin)
A
done
102-Eurospace
C-3 & C-4
44
The requirement is “easily” understandable as it is
expressed as 95% of time, that is 2 x sigma.
R
It could be interesting to detail how to interpret the
requirement if it is not 68, 95 or 99% !
Considered basic knowledge of Gaussian distributions, no added value in the context of this standard.
Dispositions:
A
Accept comment as written
AM
Accept comment with modification (disposition with justification required)
R
Reject comment (disposition with justification required)
Page 25 of 25