(This page should ultimately be replaced by a JIRA query against the envisioned future JIRA reimplementation of the change request database, using labels to represent "DM is interested in this".  At the moment it is manually maintained.)

This page is manually maintained (primarily by Gregory Dubois-Felsmann and Tim Jenness).  It contains change requests originated by DM as well as ones from or affecting other LSST subsystems which the editors believe will be of interest to DM staff.  It also omits certain manifestly DM-related change requests that are primarily concerned with PMCS technicalities and will not be subject to full CCB action.  These change requests are always available by querying the database for DM-originated requests.  The editors welcome comments on this policy!

We are not generally including LCRs concerning matters like budget adjustments and routine milestone changes.

Principal references:

LCRTitleStateDocuments AffectedSummary and commentsRelated Issues

Update LSE-78 Rubin Observatory Network Design Document

LSE-78 (Rubin Obs Network Design Doc)LSE-78 is the top-level design document for the Rubin Observatory Long-Haul Networks connecting La Serena - Santiago - US - France. It has been quite some time since it was updated and needed a refresh, as well as being made consistent with the final "as-built" configuration that will be in place at the start of operations. This LCR requests to update the document,
LCR-2273Construct Image Differencing Templates Outside of DRP

LSE-61 (DMSR)The purpose of this Change Request is to clarify that the Data Management System will be capable of generating templates for image differencing separately from Data Release Production.

LCR-2265Clarify Special Programs Processing in LSEs 72 and 61

LSE-72 (DM-OCS ICD), LSE-61 (DMSR)Clarify how the association of acquired data with different survey programs (main/WFD vs. special-programs) is communicated from the OCS to DM.

LCR-2244Proposal for new name for the LSST Science Platform

Multiple DM-level documents use the old name.

VERA: the Vera Rubin Observatory Environment for Research and Analysis.

It was announced at the project all hands of 2020-04-09 that the name “Rubin Science Platform” has been selected by the directorate before the formal completion of the CCB process.

LCR-2243Flowdown of "10% for users" requirement

LSE-30 (OSS)LSE-61 (DMSR)Improve the flowdown of the "10% for users" requirement on the provision of computing and storage for users.
LCR-2233Simplify Image Capture

LCR-2187U-Band Filter Fabrication Non-conformance Waiver

LCR-2174Move VO Services Effort from 1.02C.06.02 to

LPM-44, LDM-294Development of the external (mainly IVOA) data services is being moved from the SLAC group to the SQuaRE group.
LCR-2166Clarify Requirement DMS-REQ-0183


DMS-REQ-0183 as currently written erroneously implies that we must provide a secondary link between the Base and Archive (LDF) that is capable of twice the provisioned capacity of the primary link.  That is an overstatement and is not required for operations or catch up, nor is it feasible from a cost standpoint, nor is the it baseline Base - Archive Network Design.

This LCR corrects the wording of this requirement to reflect the real need, as well as the design baseline.

(More detailed explanation appears in a comment on this LCR.)

LCR-2148Purchase DM Production Hardware in Ops

DM is no longer responsible for providing hardware for processing DR1 & 2. Returns $8.1M to project contingency.
LCR-2104Replace "LSSTC Board" in LSR/OSS Data Access and Security Reqs

LSE-29 (LSR), LSE-30 (OSS), possibly LSE-61 (DMSR)Removes obsolete language about the "LSSTC Board" controlling operational policies for data rights and IT security.
LCR-2076Add AuxTel Spectrograph IT Equipment Installation Activity

NoneThere will be several pieces of IT equipment to install when the AuxTel spectrograph arrives in Chile, e.g. control servers, etc. This activity was previously considered part of IT-514, but that activity is complete and this is on a different and later schedule.
LCR-2073Update LSE-309 Summit Base ITC Design


LSE-309 was baselined in August 2017. Since that time, much has occurred, and the design and implementation of ITC in the Summit, Base, and Summit-Base network has gone forward. This LCR provides updated information to better reflect the "as-built" systems.
LCR-2045Commissioning De-Scope LSSTCam Observing and SV Mini-Surveys

Removes 2 months of Science Pipelines testing from the Commissioning Plan. Reduces SV mini-survey from 3 months to 2 months, resulting in smaller survey areas.
LCR-2008Restore OSS-REQ-0033

LSE-30 (OSS), LSE-61 (DMSR, flowdown only)OSS-REQ-0033 was removed from the OSS by LCR-899.  It has recently been discovered that this broke the flowdown for two existing DM requirements, but also that this requirement applies in some respects to the whole Observatory, not just to the scheduler itself.
LCR-2004OSS Omission/Typo in OSS-REQ-0387

LSE-30 (OSS), LSE-61 (DMSR)OSS-REQ-0387 (Photometric Performance) was belatedly flowed down from the LSR in LCR-924.  This change request corrects a transcription error from the implementation of that LCR, as well as fixing a long-standing typo in the transcription of these parameters from the SRD.
LCR-1934LPM-72 Scope Options Update


LCR-1933Put Lower Bound on Prompt Data Delivery - L1PublicT

LSE-29 (LSR), LSE-30 (OSS), LSE-61 (DMSR)Introduce a requirement not to release Level 1 / Prompt data products, other than alerts, before L1PublicTMin (6 hours, TBR) after image acquisition.
LCR-1923De-Scope Camera DAQ Crosstalk Correction Support

LSE-59Camera would like to descope the requirement to provide crosstalk correction in the DAQ (that had been intended to support Alert Production).  Inter-CCD crosstalk within a raft has been measured to be very small; inter-raft crosstalk is expected to be very small as well and will be measured soon.
Consequence: if the Camera does not do it, then DM will have to do it in AP.  If it's limited to intra-CCD crosstalk, then this is already within the HSC experience base and probably has little impact; if it's inter-CCD, intra-raft, though, it has a significant architectural impact on AP and may also have a real impact on the alert latency budget.  (If there is inter-raft crosstalk, there's no existing architecture to handle it and we have a significant risk.)

LCR-1916Clarify Prompt Data Products in LSE-163

LSE-163 (DPDD)


  • more clearly describes how forced photometry is handled by adding an additional table schema to the document, and specifies that this data will be included in the alert packets;
  • clarifies the distinction between "Prompt" data products and "Data Release" data products

LCR-1883OSS and DMSR Updates to Clarify Alert-Related Contents

LSE-30 (OSS), LSE-61 (DMSR)Clarified latency, failure rate, and capacity requirements relating to the alert stream.
LCR-1854Rectify DM Science Budget

PMCS"Science staff are increasing under 2C.02.02 - the verification scope in 2C.09.02 is moving into science."
LCR-1843OSS Corrections and Refinements Identified during V&V Planning

LSE-30 (OSS)(Primarily) typographical corrections to OSS requirements arising from the analysis of the document to develop well-defined verifications.
LCR-1809Update of Master Security Policy

LPM-121"... require the selection of specific security controls for each subsystem's computational resources. Additionally, the master security plan now requires the implementation of a small set of baseline controls for all LSST systems unless sufficient justification has been made and a variance has been granted (or unless prohibited by a site's own security policies). ..."

LCR-1788Modify LSE-68 to Reflect Actual Interface

LSE-68"The DAQ API delivers pixel data in an in-memory representation different from the ICD.  This LCR changes the ICD to match the API, as it is considered infeasible to change the API to match the ICD."
LCR-1728Update Science Platform Vision Document LSE-319 to Current Design

LSE-319Updating "LSE-319 to better match the current state of the LSP design and nomenclature. The major changes are to more explicitly describe what is meant by 'next-to-data' processing and to confirm the VO-orientation of the LSP interface design."
LCR-1711Update Summit and Base IT and Networks Plan


LCR-1703Fix Conflicting LSR (LSE-29) Requirements

LSE-29Remove normative text which refers to the use of snap differencing for cosmic ray rejection, as it is in conflict with the existing requirement to support the Alternate Standard Visit (1x30s).
LCR-1664Specify Scientific Visualization Coordinate System for Camera Data

LSE-30, LSE-349 (new)Adopt LSE-349, "Defining the Transformation Between Camera Engineering Coordinates and Camera Data Visualization Coordinates", as a baseline, and insert reference to it into the OSS (LSE-30).
LCR-1578DM-10 Delay DM Portal Development

Implements Portal descope DM-10. Some details in DMTN-096.

LCR-1565Correction to LCR-1403 Implementation

See original LCR below.
LCR-1563Update Identity Management Concept of Operations

LSE-279Adding LDAP group naming conventions for LSP/DAC access rights.
LCR-1554Correct flowdown of residual ellipticity correlation requirements to LSR and OSS

LSE-29, LSE-30

Update: The problem was found to originate in the flowdown from the SRD to the LSR. The LCR has been modified with new language for both the LSR and OSS that, finally, correctly implements the SRD specification. Outside the scope of the LCR, the DM-SST is researching whether the original SRD requirement still properly supports the needs of weak lensing science.

OSS-REQ-0234 (10-year Ellipticity Residuals) and OSS-REQ-0390 () are almost duplicates and clearly redundant. One should be removed. There is also a parent requirement, OSS-REQ-0389 () that is not very useful.

There are also indications that the flowdown from the SRD to the LSR and OSS was not done correctly; Jim Bosch and Gregory Dubois-Felsmann are investigating.

LCR-1553Update LSE-239: Base Facility Data Center Design Requirements


Primarily updates intended to assist the verification process.

(Denied: to be handled entirely in JIRA.)

LCR-1503Parallelize Camera Reverification on LSSTCam and ComCam on Telescope

(PMCS)Parallelize on-sky data collection with ComCam with "white room" reverification of the full Camera on-Summit.
LCR-1494Add LSE-400 as an ICD for Header Service

LSE-400, LDM-638Promote Header Service requirements to system level, in effect.
LCR-1478Remote Monitoring of System Operations

OSS (LSE-30)Clarify and limit remote monitoring expectations with a new OSS requirement.  Supersedes LCR-1278 (Remote Monitoring of System Operations).
LCR-1473Update LPM-19 Change Control Process

LPM-19Limit membership of CCB, clarify voting process.

Additional OSS Requirements Flowdown to LSE-61

LSE-61Flow down OSS provenance requirements (OSS-REQ-0172, OSS-REQ-0122) and reproducibility requirement (OSS-REQ-123) to additional DM requirements


Update LSE-61 DMS-REQ-0274 Re: Alert Packet DIASource History Retention

LSE-61Update requirement DMS-REQ-0274 to be in sync with the DPDD (LSE-163) to indicate that only 12 months of DIASource history will be included in the alert packets.
LCR-1459Updates to the Data Products Definition Document, LSE-163


LCR-1426Refine LSE-68 DAQ-DM interface

LSE-68Refine interface with regard to image naming, metadata, units, and events.
LCR-1425Modify DMS requirements to include creation and display of HiPS and MOC data

LSE-61, then consequentially LDM-151, LDM-554, and the Sizing Model

Implements .

LCR-1424Define Image Naming Convention

LSE-30, LSE-71, LSE-72, LSE-62Specify the identifiers to be applied to image data at the time of acquisition and ingest to DM.
LCR-1420Update LSE-140 including LCR-733

LSE-140This LCR applies LCR-733 to LSE-140 and corrects some other minor issues.  It does not attempt to fully define the telemetry items expected from the auxiliary instrumentation; that will be left for a later LCR.
LCR-1419Remote Operability

LSE-30, LSE-62

LCR-1405Rewrite OSS-REQ-0161

LSE-30This is the "Deep Detection and Measurement Quality" requirement. It is argued that it is "both unhelpful to scientists and awkward for DM to implement now" and "asking for something DM is not planning to deliver because it's not actually something anyone wants."

LCR-1403Update Base and Long-Haul Network Activities


The Base Network plan has been delayed relative to the baseline due to the updated schedule for construction and occupancy of the Base Facility. This LCR reflects the updated dates.

The US Network plan has been delayed while we coordinated with ESnet for dedicated 2 x 100 Gbps links between Atlanta and Chicago. The ESnet links provide additional path diversity and guaranteed latency for prompt processing over leased service from internet2. This coordination is documented in a request document and technical requirements document, which when finalized will be posted in docushare. The activities and dates in this LCR reflect the implementation plan and schedule for the ESnet links.

LCR-1395Proposed Data Rights Policy Document LPM-261

LPM-261Codifies a proposed data rights and data access policy. Will require SAC review and agency approval.
LCR-1392Restore requirement to OSS from LSE-369 scheduler requirements

LSE-30Add OSS-REQ-0378 back to OSS so that DM tracing will work correctly.LCR-899
LCR-1375Update Base Data Center IT Installation and Configuration Activities


Add Base Data Center activities in PMCS

LCR-1367 folded into final version, which required going for NSF approval.

LCR-1367Change DLP-533 Milestone and Predecessors

"Denied" but in practice folded into LCR-1375.
LCR-1364Updated LSE-131 (EPO/DM ICD)

LSE-131Mainly reduction of scope.
LCR-1353Reorganization of Early Integration Activities

PMCSClarification and augmentation of the list of planned cross-subsystem early integration activities.
LCR-1348New Reference Simulated Survey, baseline2018a

LCR-1344Add Performance Metrics to

LSE-61Add database and image access requirements and ability to calculate science KPMs.
LCR-1343Revisions to LSE-239 Base Data Center Requirements


LCR-1332Update LSE-30 (OSS) to Better Define OSS-REQ-0164

LSE-30Improves and modernizes the language concerning the definition of completeness and reliability tests for DM.

LCR-1309Update DM Documentation Regarding Special Programs

LSE-29, LSE-30, LSE-61

LCR-1302LSR-REQ-0034 Clarification

LSE-29Clarify the requirement concerning the saving of Observatory engineering data and the like.

LCR-1243Update LSE-239 Base Data Center Requirements


LSE-239 was developed to provide the definition of the Base Data Center (BDC) requirements for the Base construction contracts and the BDC Information Technology and Communications (ITC) infrastructure design. Since that version, much has been learned and the requirements have been migrated into the project SySML requirements model. A new version of LSE-239 has been prepared as a document generated from Magic Draw, and has also been substantially re-organized, to more cleanly separate those sections directly applicable to the Base Facility construction contract (Sections 1 - 3), versus those more targeted at the ITC infrastructure design (Appendices I and II). Finally, as the formerly baseline Tape Library has been recommended to be replaced in the BDC ITC design baseline (LCR-781 and follow-on), requirements related to the Tape Library have been deprecated into Appendix III.

LCR-1238Implement DM and OSS part of LCR-786

LSE-61, LSE-30

LCR-1230Update to LSE-75

LSE-75Defining feedback for Active Optics and guider. KTL rewording with more specifics after discussion with Sandrine.
LCR-1214Clarify DM's Level 1, 2, and 3 Terminology for the Science Community

LSE-163, LPM-231Defines a new language for the three categories of data products, replacing Level 1, Level 2, and Level 3 in user-facing documentation.
LCR-1203Searchable - Interactive Nightly Reports

Need to determine what DM will need to do to meet this requirement.
LCR-1154Stand Up Data Access Rights Working Group - Put LPM-221 under Change Control


LCR-1070DM Milestones for Base LAN and Summit Network

LCR-1068Revised Commissioning Plan LSE-79


LCR-1065Date Update for the DM/EPO ICD Phase 3 Milestone

LCR-1064Add Priorities to LSE-61


Add priorities to the baselined version of the document that are already part of the MagicDraw model (added as part of )

LCR-1048Update Summit Network Installation Schedule

LCR-1034Auxiliary Telescope Spectrograph Instrument and Detector Schedule and Cost Update

Updates the schedule and cost of the procurement of the Auxiliary Telescope Spectrograph Instrument. Details of the change are not yet available ().

LCR-1024Tie LSE-163 into OSS

LSE-30 (OSS); others indirectly, LSE-61Resolves a long-running formal gap in our requirements flowdown. Makes the contents of the DPDD (LSE-163) authoritative in deriving DM-level requirements (i.e., in the DMSR, LSE-61) by stating in the OSS that the data products generated by DM shall conform to the DPDD.
LCR-1021Adjust Dates for DWDM Equipment Installation

PMCSNotes ~60 day delay in the installation of the Summit-Base and Base-Santiago DWDM equipment, triggered by late delivery from the equipment vendor. New schedule shows installations complete by roughly November 2017.
LCR-1018Follow up to New Camera Image Types (LCR-773) to flow down requirements to subsystem specs and ICDs

LSE-59, LSE-71; DM impact to be analyzed

Adds the new image types introduced by LCR-773 (New Camera Image Types) to the Camera requirements and OCS-Camera ICD. Superficially this doesn't require a response in DM-level documents; however, the exploitation of the new image types is driven by calibration requirements and so most likely they should eventually appear in DM documents.

Note that as of  LCR-773 itself is Approved but not Fully Implemented.

LCR-1013Place the LSST Science Platform Vision Document under Change Control


LCR-1006Update DM-OCS ICD, LSE-72, to reflect DM design changes and to match recent LSE-70/LSE-209

LSE-72, LDM-230Updates LSE-72 to match current design work. Incorporates changes from LCR-780 and LCR-888.
LCR-1005LSE-209 Software Component Document Reformat and Reqs Refresh 

LSE-209, likely LSE-72This is mostly a cleanup pass on a key OCS middleware definition document. The DM-to-OCS interface depends on its contents, so it's likely that some consequential changes to LSE-72 will be needed.
LCR-1004Withdraw LSE-77, "Infrastructure Interfaces Between Data Management and the Base Facility"

LSE-77, possibly LSE-239In 2015, the project shifted from the then-existing DM-to-T&S ICD LSE-77 to a new "Base Data Center Requirements" document, LSE-239, to capture the needs of DM for data center space at the Base. LSE-77 became effectively a dead letter in the process. This change request is intended to just clean that up.
Final result: LSE-77 has been withdrawn.

LCR-983Integrate DM and Camera Data Systems Early

PMCS, possibly ICDs, LSE-61Perform additional early integration activities, notably around the use of the CCOB camera test facility to generate data to be ingested into DM on a regular basis.
LCR-974Update Network Requirements in LSE-61

LSE-61One new requirements, modifications to 3 others.
LCR-964Summit Computer Room Requirements Document

LSE-299 (new)Consolidates all planned compute hardware needed on the Summit (except what is actually in the domes).
LCR-963Summit - Base ITC Design Document

LSE-309 (new)

Product of Jeff Kantor's Summit-Base Tiger Team

Touches on almost all DM's interfaces with the other systems.

LCR-962Flowdown LSE-163 (DPDD) to LSE-61 (DMSR)

LSE-163, LSE-61Includes a handful of unrelated requirements changes/additions. Some text updates to DPDD.
LCR-952DM Management and Science Staffing

Assigns Wil O'Mullane as CAM for 02C.01.01 and 02C.02.*, and adds budget to support DM Science Analysts at UW.

Minor updates to LSE-63

LSE-63 (Data Quality Assurance Plan)LSE-63 has not been updated since 2011. This update includes some minor modernizations based on current best practice and removes mention that we are currently in R&D phase.
LCR-924Duplicate LSR Data
Performance Metrics in OSS for DM Flow Down

LSE-30 (OSS)

Flows LSR-REQ-0093, LSE-REQ-0094 and LSR-REQ-0097 to OSS so that DM can include them in DMSR for verification of the performance metrics (via ).

LCR-921DM to Provide Service for Publishing Predicted Visit Sequence


Publish telescope position and predicted schedule to the community (via ).

LCR-908Keep all Data Releases loaded in databases

LSE-30 (OSS) and many subordinate documentsAdopt the following requirement: "The LSST project shall maintain user access to the contents of all Data Releases. This facility may be provided with reduced performance and capacity for Data Releases older than the most recent one, but be qualitatively identical otherwise." in place of the current policy of maintaining access only to the two most recent data releases.
LCR-900DM S17 Mid Cycle Replan

(PMCS)Implement S17b plans for NCSA, SQuaRE, and AP with some small tweaks to other subsystems.
LCR-899Scheduler Requirements Control

LTS-347, possibly LSE-62Promote the scheduler requirements in LTS-347 to project-level change control, moving them to an LSE-* document.
LCR-888Proposed Meta-data header client for LSST images

LSE-72, LDM-230, probably numerous othersProposes that a common Summit-Base service be created that extracts all observation metadata (from published telemetry or the EFD) intended to be packaged with the image files, storing an artifact containing all this metadata as "headers" for later retrieval.Q: Does this have anything to do with the reformatted EFD database? -XW
LCR-851Update to LSE-151

LSE-151 "Interface Control & Compliance Management Process"Clarifies language surrounding ICDs and documents that describe or actually are the implementations of the interfaces controlled by ICD.

Update LSE-78 LSST Observatory Network Design

LSE-78LCR-849 is to make LSE-78 consistent with and refer to the Network Sizing document LDM-142.  Requested CCB if this can be voted on via the electronic voting process.  I think it is non-controversial and was discussed at some length in the DM TCT when we last updated LDM-142. It would be good to get this done, as there are a number of more significant changes to the same documents coming very soon as a consequence of Tiger Team activities.
LCR-838Auxiliary Telescope Scheduler

LTS-187 (draft: SPT-372)

LCR-836Typographic correction to LSE-69 to match LSE-130


This is a trivial typographic correction that was requested a long time ago in .

LCR-835Camera Heterogeneous Sensor Focal Plane

Implicitly sharpens requirements on ability to determine the correct pixel geometry upon data ingest from Camera to DM. May have an implication for the generation of difference imaging templates, at the (~annual) template-creation level and/or at the nightly template-warp-instantiation level.


Updates to DM/EPO interface requirements (LSE-131)


See substantive discussion in the DM Leadership Team Meeting 2017-03-20.

LCR-788Transfer Task Framework from 02C.07 to 02C.06

(PMCS)Moves the Task class and a cluster of related classes and interfaces to be a responsibility of the SLAC group.
LCR-787Commissioning Re-Plan 2016

LSE-79See also the February 2017 Commissioning Review.
Awaiting the report of the review committee. 

LCR-786Eliminate Base Network Outage Buffer; Expand Summit Camera Image Buffer


Kevin Long is awaiting guidance on what WBS element to use for the additional budget for the enlarged buffer.

The "documents affected" is "Unclear" because it has not been completely decided whether to implement this as a change to requirements or as a specification that exceed the requirement. This is a separate question both at system and at Camera level.

LCR-785Observatory Operations Server

Unclear; may require a new ICD. Would also affect DM design documents.

LCR-783Commissioning Cluster Services

Appears in DM design documents

LCR-782Additional OCS Driven Services for Archive Center Access

LSE-72, possibly LSE-140Provide a means for the OCS to launch predefined batch processing actions at the Archive Center. Likely to be used for, e.g., producing synthetic calibration images following the collection of the input flats, bias frames, etc.
LCR-780Eliminate Engineering & Facilites Database Copies in Offline Archive Centers

LSE-72, LDM-230

Requires changing EFD interface with OCS to be the ingest to the Reformatted EFD.

: discussed at an OCS-DM meeting. Further discussions planned for .

LCR-773New Camera Image Types

LSE-30 (OSS)Adds requirements for a pinhole filter and for the capability to take filterless images.
LCR-747Unified LSST Authentication and Authorization Services

LSE-279Provides unified authentication and authorization technical services to assure authorized individuals access LSST services and systems.
LCR-745Targets of Opportunity requirements

LSE-29 (LSR), LSE-30 (OSS), LSE-62 (OCS reqts.)Provides requirement flowdown for the need to handle target-of-opportunity observing.
LCR-733LSST CCD, CCS, and DAQ for the Auxiliary Telescope Spectrograph

LSE-140 and many othersRequires consequential changes to LSE-140 because of the change to direct spectrograph-to-DM image retrieval.

The details of the timeline of capabilities required of DM to support the spectrograph, starting 8/2018, remain under analysis. 

LCR-687Alternate Standard Visit with 30s single exposure

LSE-29 (LSR), LSE-30 (OSS)Requires that DM be able to handle two types of standard visits: two 15s exposures, or one 30s exposure. Somewhat vague on the question of how closely the two types of visits could be interleaved.
LCR-586Update LSE-209 Software to OCS ICD

LSE-209A further round of technical updates to the OCS-to-subsystem device interface. The draft already serves as the basis for the prototype and early integration work that is ongoing.
LCR-581Calibration Hardware Requirements Update

LSE-30 (OSS), LSE-60, LSE-140 (DM ICD)

LCR-458Support for "Deep Drilling" observing scenario

See for a task relating to unblocking this change request.

Ultimately "Rejected" as no longer germane.