1. HMI Top Level Requirements
Rock Bush
Stanford HMI Program Manager

2. Requirements Overview
Basis of Requirements
Requirements Sources
Draft HMI Functional Specifications

3. Basis of Requirements HMI Science Objectives HMI Observation Sequences
Duration of mission
Completeness of coverage
HMI Science Data Products
Roll accuracy
Time accuracy (months)
HMI Observation Sequences
Duration of sequence
Cadence
Completeness data sequence
Noise
Resolution
Time accuracy (days)
HMI Observables
Sensitivity
Linearity
Acceptable measurement noise
Image stability
Time rate (minutes)
Orbit knowledge
HMI Instrument Data
Accuracy
Noise levels
Completeness of filtergrams
Tuning & shutter repeatability
Wavelength knowledge
Image registration
Image orientation jitter
HMI Instrument Concept
Mass
Power
Telemetry
Envelope
Subsystem requirements
CCD: Thermal environment
ISS: pointing drift rate, jitter
Legs: pointing drift range

4. Basic Requirements Sources
SDO Level 1 Requirements
SDO Mission Requirements Document (MRD)
Summary of spacecraft and instrument driving requirements
HMI Instrument Functional Specification
Top level HMI requirements – part of the HMI contract statement of work
HMI Instrument Performance Document (IPD)
Detailed HMI science drivers and flowdown to subsystem requirements
SDO Mission Assurance Requirements
SDO spacecraft and instrument requirements for design, fabrication, verification, etc.
HMI Performance Assurance and Implementation Plan (PAIP)
HMI implementation of the SDO MAR
HMI to Spacecraft Interface Control Documents (HMI-S/C ICD)
Ground System Interface Control Document

5. HMI Requirements
The HMI Functional Specification is the contractual link between the SDO project office and the HMI development team.
The Functional Specification documents the key instrument parameters needed to meet the HMI goals.
The Draft Functional Specification is summarized in the next chart, and the verification will be discussed during the test and integration presentation.
The Functional Specification is under review and will be finalized as part of the Phase C/D contract negotiations.
The HMI Instrument Performance Document (IPD) details the HMI observations required to meet the science goals, and the derived subsystem design and performance requirements.
The IPD contains three sections:
Instrument observations required to meet the science objectives
Instrument performance requirements needed to obtain the observations
Detailed subsystem design specifications needed to obtain the specified performance
The HMI Performance Document is modeled after the Michelson Doppler Imager Instrument Performance Specification.

6. HMI Functional Specifications Summary