1. Introductory sections

1.1. Interface Identification

This Interface Control Document (ICD) defines the requirements and implementation details of the data exchange interfaces as indicated by SKA1-SYS_REQ-2738 [AD6]:
I.S1M.SDP_CSP.001 “SKA1-Mid SDP_CSP Visibility Data Interface”
I.S1M.SDP_CSP.002 “SKA1-Mid SDP_CSP Pulsar Search Data Interface”
I.S1M.SDP_CSP.003 “SKA1-Mid SDP_CSP Pulsar Timing Data Interface”
I.S1M.SDP_CSP.004 “SKA1-Mid SDP_CSP Transient Buffer Interface”
[Note: the interface identifier used is S1t.SDP.XXX.nnn, where:
1 = SKA1,
t = Telescope: M for MID, L for LOW,
xxx = interfacing element 2,
nnn = identification number]
The ICD is identified in the Document Management System as 300-000000-002_ 02, where:
300-000000 = MID Telescope
002 = Document reference number
03 = Revision of the document.

1.2. Applicable and Reference documents, including applicable standards

1.2.1. Applicable documents

The following documents are applicable to the extent stated herein. In the event of conflict between the contents of the applicable documents and this document, the applicable documents shall take precedence.
[AD1] SKA-TEL-SKO-0000025 , “SKA Interface Management Plan ”, Rev 02
[AD2] ISO/IEC 7498-1:1994 , “Information Technology - Open Systems Interconnection – Basic Reference Model
[AD3] SPEAD: Streaming Protocol for Exchanging Astronomical Data (Revision 1): Doc number: SSA4700-0000-001
[AD4] HDF5: Hierarchical Data Format (HDF) Version 5. https://www.hdfgroup.org/HDF5/doc/RM/RM_H5Front.html
[AD5] PSRFITS: Pulsar Search Flexible Image Transport System http://www.atnf.csiro.au/research/pulsar/index.html?n=PsrfitsDocumentation.Txt
[AD6] SKA-TEL-SKO-0000008 , SKA Phase 1 System (Level 1) Requirements Specification, Rev 10
[AD7] Documenting Software Architectures 2nd edition: SEI Series in Software Engineering.

1.2.2. Reference documents

The following documents are referenced in this document. In the event of conflict between the contents of the referenced documents and this document, this document shall take precedence.
[RD1] 300-000000-023 , Interface Control Document SaDT to CSP (MID), Rev 1.
[RD2] 300-000000-025 , Interface Control Document SaDT to SDP (MID) , Rev 1.
[RD3] SKA-TEL-SDP-0000027, SDP Pipelines Design, Rev 02
[RD4] 300-000000-029 , SKA1 Interface Control Document SDP to TM Mid, Rev 02
[RD5] SKA-TEL-SKO-0000307 SKA1 Operational Concept Document, Rev 02
[RD6] SKA-TEL-SDP-0000018 SDP Compute Platform Design Document, Rev 02
[RD7] 100-000000-002 Data Rate Calculation spreadsheet included with the SDP-CSP ICD, Rev 03
[RD8] Simon Ratcliffe https://github.com/ska-sa/spead2
[RD9] Simon Ratcliffe https://github.com/ska-sa/PySPEAD

1.3. Roles and responsibilities

The SKA Office is the Owner of the interface, and is responsible for the initial identification and description of the interface, and for nominating Leading and Following Parties. The point of contact of the Owner is the SKA Office Chief System Engineer.
The SDP Consortium is the Leading Party, and is responsible for defining the interface requirements and implementation details; for providing methods and procedures for verification of the interface; for verifying the interface for integration and acceptance purposes; and for verification of SDP hardware and software (without the interface being made). The point of contact of the Leading Party is the SDP Consortium System Engineer.
The CSP Consortium is the Following Party, and responsible for reviewing the ICD and verification of CSP interfacing hardware and software (without the interface being made). The point of contact of the Following Party is the CSP Consortium System Engineer.

1.4. Interface scope

This interface includes the following OSI layers.
Layers 1 to 2 are described in [RD1] and [RD2].
This document describes data items transferred by the following interfaces:
Visibility Data Interface”
I.S1M.SDP_CSP.002 “SKA1-Mid SDP_CSP Pulsar Search and Fast Transient Data Interface”
I.S1M.SDP_CSP.003 “SKA1-Mid SDP_CSP Pulsar Timing Data Interface”
I.S1M.SDP_CSP.004 “SKA1-Mid SDP_CSP Transient Buffer Interface”
Data items transferred by other interfaces, i.e. I.S1M.SDP_TM.001, may be mentioned where relevant, but will not be described in any detail. Refer to the referenced ICD or document for further detail.

1.5. Functional Context

From a functional perspective, the CSP and SDP are split into two distinct logical instances, which map to the respective telescopes on the two SKA sites.
When referring to requirements or specifications of relevance only to a particular telescope, the form <element>-<telescope> will be used (e.g. SDP-Mid refers specifically to the SDP instance that forms part of the SKA1-Mid telescope).
1: SKA1-Mid telescope SDP_CSP interfaces