Vol_7_OPTISIG_User_Manual_and_ICD_900MAN2254_RevC.pdf

FOR OFFICIAL USE ONLY

900MAN2254C DISTRIBUTION 21.2.3

VOLUME 7

Special Report

Optical Signatures Code

Volume 7

OPTISIG Users’ Manual and

Interface Control Document

Version 7.4.1

June 2016

SPONSORED BY THE MISSILE DEFENSE AGENCY

NOTICE – The views, opinions, and/or findings contained in this document are those of the author(s) and should not be construed as an official Department of Defense position, policy, or decision unless designated by other official documentation.

DISTRIBUTION STATEMENT C – Distribution authorized to U.S. Government Agencies and their contractors; Critical Technology, Export Controlled; 30 November 2015. Other requests for this document shall be referred to MDA/ESP (Attn: Mark Underwood or active program COTR), 5224 Martin Road, Redstone Arsenal, AL 35898 or higher DoD authority.

WARNING – This document contains technical data whose export is restricted by the Arms Export Control Act (Title 22, U.S.C. sec 2751 et seq.) or the Export Administration Act of 1979, as amended, Title 50, U.S.C., App. 2401 et seq.

Violations of these export laws are subject to severe criminal penalties.

Disseminate in accordance with the provisions of DoD Directive 5230.25.

DESTRUCTION NOTICE – For classified documents follow the procedures in DoD 5200.22-M, Industrial Security Manual, Section 11-19 ORD or 5200.1-R, Information Security Program Regulation Chapter IX. For unclassified, limited documents destroy by any method that will prevent disclosure of contents or reconstruction of the document.

NOTICE – This document contains information that may be exempt from mandatory disclosure under the Freedom of Information Act.

i

NOTICE

This document contains information that may be exempt from mandatory disclosure under the Freedom of Information Act.

Per Department of Defense (DoD) Manual 5200.01, Volume 4, February 24, 2012, Objective

Simulation Framework (OSF) documents, including this document, are considered to be

Unclassified but For Official Use Only (FOUO) and exempt from the Freedom of Information

Act (FOIA) as a result of compilation. The OSF software and documentation are considered export controlled. Though no discrete portion of this document is considered to be export controlled, the information that may be extracted from this document as a whole is considered to be export controlled and therefore may be exempt from FOIA and is considered FOUO.

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1. AGENCY USE ONLY (Leave Blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

27 June 2016 Special Report

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS

Optical Signatures Code Volume 7 – OPTISIG Users’ Manual and Interface Control

Document Version 7.4.1

OSF Contract No.:

HQ0147-11-D-0015

Task Order 9

CDRL A031

6. AUTHOR(S)

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT

NUMBER

900MAN2254C

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING AGENCY

REPORT NUMBER

Missile Defense Agency

MDA/ESP

5224 Martin Road

Redstone Arsenal, Alabama 35898

Attention:

11. SUPPLEMENTARY NOTES

12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b DISTRIBUTION CODE

DISTRIBUTION STATEMENT C – Distribution authorized to U.S.

Government Agencies and their contractors; Critical Technology, Export

Controlled; 30 November 2015. Other requests for this document shall be referred to MDA/ESP (Attn: Mark Underwood or active program COTR), 5224

Martin Road, Redstone Arsenal, AL 35898 or higher DoD authority.

13. ABSTRACT (Maximum 200 words)

The OPTISIG Users’ Manual and Interface Control Document provides user instructions for incorporating the OPTIcal

Signature In-line Generator (OPTISIG) subroutine into the user’s own simulation code. The manual also gives details on the method of accessing the Target Model Libraries (TML). OPTISIG simulates target geometry, trajectories, and thermal response to compute optical signatures for sensor pass bands from visible through long wavelength infrared. OPTISIG is part of the Optical Signatures Code (OSC) suite of tools developed by Teledyne Brown Engineering, Inc. for the Missile Defense

Agency, the U.S. Army Space and Missile Defense Command, and the Air Force Research Laboratory in support of ballistic missile defense programs

14. SUBJECT TERMS 15 NUMBER OF PAGES

OPTISIG, OSC, optical signatures, infrared, IR, missile defense 60

16. PRICE CODE

17. SECURITY CLASSIFICATION OF

REPORT

18. SECURITY CLASSIFICATION OF THE

PAGE

19. SECURITY CLASSIFICATION OF

ABSTRACT

20. LIMITATION OF ABSTRACT

UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED UL

Standard Form 298 (Rev. 2-89) Prescribed by ANSI Std. Z39-18

298-102 iii

SPECIAL REPORT

900MAN2254C

Optical Signatures Code

Volume 7 Optisig Users’ Manual and Interface Control Document

Version 7.4.1

June 2016

NOTICE – The views, opinions, and/or findings contained in this document are those of the author(s) and should not be construed as an official Department of Defense position, policy, or decision unless designated by other official documentation.

DISTRIBUTION STATEMENT C – Distribution authorized to U.S. Government Agencies and their contractors; Critical Technology, Export Controlled; 30 November 2015. Other requests for this document shall be referred to MDA/ESP (Attn: Mark Underwood or active program COTR), 5224 Martin Road, Redstone Arsenal, AL 35898 or higher DoD authority.

WARNING – This document contains technical data whose export is restricted by the Arms Export Control Act (Title 22, U.S.C. sec 2751 et seq.) or the Export Administration Act of 1979, as amended, Title 50, U.S.C., App. 2401 et seq.

Violations of these export laws are subject to severe criminal penalties.

Disseminate in accordance with the provisions of DoD Directive 5230.25.

DESTRUCTION NOTICE – For classified documents follow the procedures in DoD 5200.22-M, Industrial Security Manual, Section 11-19 ORD or 5200.1-R, Information Security Program Regulation Chapter IX. For unclassified, limited documents destroy by any method that will prevent disclosure of contents or reconstruction of the document.

NOTICE – This document contains information that may be exempt from mandatory disclosure under the Freedom of Information Act.

Prepared For

Missile Defense Agency

Redstone Arsenal, Alabama

Under Contract Number

HQ0147-11-D-0015, Task Order 9

Prepared By iv

DOCUMENT CHANGE LOG

Revision Date Pages Affected Description

Initial 31 October

All

This document was prepared and released in accordance with CDRL A031.

A 09 July 2014 4-21 Corrected order of columns in Table 4-11.

A-1-A-5 Added solid lines to indicate data record divisions.

B 14 March 2015 Various See Document Release Notes 21.2.2 for all changes.

C 27 June 2016

Cover, i-vi, 4-20, 4-21, 4-24, 4-25, 4-26, 4-27, and Appendix B

Updated distribution markings, task order number, sponsor, revised section 4.3.11 (new instructions for Optional COMMON Block THERMIO), revised section 4.3.15 (new variable in Optional COMMON Block SIM), added section

4.3.18 (new Optional COMMON Block THRMIN), and revision history v

ABSTRACT

The “OPTISIG User’s Manual and Interface Control Document” provides user instructions for incorporating the OPTIcal Signature In-line Generator (OPTISIG) subroutine into the user’s simulation code. The manual also gives details on the method of accessing the

Target Model Libraries (TML). Refer to the companion document, “OPTISIG Algorithm

Notes,” for additional details of the simulation methods used in OPTISIG.

APPROVED BY:

vi

FOREWORD

Teledyne Brown Engineering, Inc. (TBE) originally developed OPTISIG, TIGER, and the

Target Model Library, including the documentation, as part of the Ground-based

Surveillance and Tracking Systems (GSTS) program, under the direction of James Brazzel and Brent Montgomery, of what was then called the U.S. Army Space and Strategic

Defense Command (USASSDC), Huntsville, Alabama. OPTISIG is currently part of the

Operation, Maintenance, and Sustainment of the Hardbody Toolset of the MDA Electro-

Optical/Infrared (EO/IR) Toolkit for Contract Number HQ0147-11-D-0015, under the technical direction of Dr. Mark Underwood (MDA/ESP) for the Missile Defense Agency.

Recent previous releases were issued under the technical direction of Mr. Cliff Burson

(MDA/ESP) and Ms. Carol Barclay (USASMDC/ARSTRAT).

The following have contributed to the development, programming, and documentation of the database and software: John Robinson, Robert Bradford, Andrew Edwards, Theresa

Drouin, Diane Hochmuth, Jeffery King, W. Brown Wellman, and Arthur Woodling.

vii

Table of Contents

DOCUMENT CHANGE LOG .................................................................................................. iv

1. Introduction ..................................................................................................................... 1-1

1.1 Functional Overview ............................................................................................... 1-1

2. Software Overview ......................................................................................................... 2-1

2.1 Availability ................................................................................................................ 2-1

2.2 Computer Requirements ......................................................................................... 2-1

2.3 User Responsibilities .............................................................................................. 2-1

3. Program TIGER ............................................................................................................. 3-1

3.1 TIGER Inputs .......................................................................................................... 3-1

3.2 TIGER Error Messages .......................................................................................... 3-2

3.3 Sample Screen Sequence for TIGER Session .................................................... 3-2

4. Subroutine OPTISIG ...................................................................................................... 4-1

4.1 OPTISIG Top-Level Functional Flow .................................................................... 4-3

4.2 OPTISIG Operation ................................................................................................. 4-5

4.3 OPTISIG Common Block Requirements ............................................................... 4-6

4.3.1 Required COMMON Block 1 (FILES) ............................................................ 4-7

4.3.2 Required COMMON Block 2 (USRINP) ........................................................ 4-7

4.3.3 Optional COMMON Block 1 (USRDYN) ...................................................... 4-11

4.3.4 Optional COMMON Block 2 (MICDYN) ....................................................... 4-14

4.3.5 Optional COMMON Block 3 (FRGDEF) ...................................................... 4-14

4.3.6 Optional COMMON Block 4 (ASCTRJ) ....................................................... 4-16

4.3.7 Optional COMMON Block 5 (RANSHF) ...................................................... 4-18

4.3.8 Optional COMMON Block 6 (CLOUDS) ...................................................... 4-18

4.3.9 Optional COMMON Block 7 (ASSTEP) ....................................................... 4-18

4.3.10 Optional COMMON Block 8 (RUNOPT) ...................................................... 4-19

4.3.11 Optional COMMON Block 9 (THERMIO) .................................................... 4-20

4.3.12 Optional COMMON Block 10 (EXTATM) .................................................... 4-21 viii

4.3.13 Optional COMMON Blocks 11 (REYTRN) and 12 (SSINN) ..................... 4-22

4.3.14 Optional COMMON Block 13 (HTFLX)........................................................ 4-23

4.3.15 Optional COMMON Block 14 (SIM) ............................................................. 4-24

4.3.16 Optional COMMON Block 15 (ETFRG) ....................................................... 4-25

4.3.17 Optional COMMON Block 16 (TENV) ......................................................... 4-25

4.3.18 Optional COMMON Block 17 (THRMIN) ..................................................... 4-26

5. OPTISIG Error Messages ............................................................................................. 5-1

5.1 Fatal Error Conditions ............................................................................................ 5-1

5.2 Recoverable Error Conditions ................................................................................ 5-1

5.3 Informative Messages ............................................................................................. 5-2

A. OPTISIG Target Model Library Format ....................................................................... A-1

B. Revision History ............................................................................................................. B-1 ix

List of Tables

Table 4-1: Access Software Subprogram Summary ..................................................................... 4-1

Table 4-2: COMMON block names used by OPTISIG .................................................................... 4-3

Table 4-3: Arguments for SUBROUTINE OPTISIG ......................................................................... 4-6

Table 4-4: Atmosphere Models (IATMOS) ................................................................................... 4-8

Table 4-5: Earthshine Models (IEARTH) ...................................................................................... 4-9

Table 4-6: Options for Target Dynamics (IDYOPT) ...................................................................... 4-10

Table 4-7: Options for Initial Temperature (ITPOPT) ................................................................... 4-10

Table 4-8: Options for Ascent Propagation (IASOPT) .................................................................. 4-10

Table 4-9: Target Parameters Accessed in USRDYN .................................................................. 4-11

Table 4-10: Fragment Parameters in FRGDEF .......................................................................... 4-16

Table 4-11: Atmosphere Data File ............................................................................................ 4-22

Table A-1: OPTISIG Target Model Library Format ......................................................................... A-1 x

List of Figures

Figure 2-1: Functional Flow Diagram of OPTISIG ......................................................................... 2-3

Figure 3-1: Sample Screen Sequence for TIGER Session ............................................................. 3-3

Figure 4-1: OPTISIG Top-Level Flow Diagram .............................................................................. 4-4

Figure 4-2: FORTAN Calling Statement for OPTISIG ..................................................................... 4-5

Figure 4-3: Coordinate System to Locate Target Space Axes ...................................................... 4-13

Figure 4-4: Dynamics Inputs for IDYOPT = 4 Option ................................................................... 4-14

Figure 4-5: Fragment Shape Modeling ..................................................................................... 4-15

Figure 4-6: Coordinate System to Locate Target Orientation ...................................................... 4-17 xi

List of Acronyms

AFRL Air Force Research Laboratory

ECI Earth Centered Inertial

GSTS Ground-based Surveillance and Tracking System

ICBM Intercontinental Ballistic Missile

MDA Missile Defense Agency

OPTISIG OPTIcal Signature In-line Generator

OSC Optical Signatures Code

SC Simulation Center

STL Scenario Target Library

TIGER Target InteGRator

TBM Theater Ballistic Missile

TML Target Model Library

USASMDC United States Army Space and Missile Defense Command

USASSDC United States Army Space and Strategic Defense Command

(USASSDC was the predecessor to USASMDC)

1-1

1. Introduction

The purpose of the OPTIcal Signature In-line Generator (OPTISIG) is to provide standardized, representative optical signatures of ballistic missiles and missile payloads or countermeasures. OPTISIG computes optical signatures for sensors with pass bands from

0.3 to 30 m, viewing targets from any sensor engagement, from launch through deployment and reentry.

The OPTISIG is a callable subroutine designed for use in acquisition and track studies, discrimination algorithm development, and system simulations. OPTISIG can operate with minimal user input. The use of a target model library (TML) frees the user from the task of researching and modeling targets as in the Optical Signatures Code (OSC). OPTISIG frees users from the limitations of pre-computed signature databases by allowing any time of day or threat scenario, instead of the single time of day restriction that interpolated databases impose. OPTISIG is based on many of the algorithms of FASTSIG; however, Teledyne Brown

Engineering (TBE) continues to add new algorithms to the software to meet the evolving needs of the user community.

OPTISIG consists of the following three components:

1) Target Model Library (TML) containing pre-defined targets.

2) PROGRAM TIGER (Target Integrator), which generates Scenario Target

Libraries (STL), and integrates OSC spectral reflectance data in the TML into band data.

3) SUBROUTINE OPTISIG, which reads the integrated STL and returns target signatures.

1.1 Functional Overview

OPTISIG is capable of treating a wide variety of targets, from launch through reentry, in a consistent and uniform manner. RVs and penetration aids (penaids) are modeled from:

spherical nose tips; cylindrical or conical body segments; and circular disk base plates, assembled into axisymmetric composite shapes, which are stored in the TML. OPTISIG is not designed as a hot exhaust plume simulation and; therefore, does not account for these

1-2 effects during boost phase. In addition, jet vane, hot nozzle, and fin modeling are not performed; modeling of these effects may be included in later versions of the code.

The user provides OPTISIG with a target identifier along with the target and sensor Earth

Centered Inertial (ECI) state vectors on each call. These state vectors are used to calculate the target viewing geometry. The target state is propagated internally by OPTISIG using 6-

DOF ballistic motion algorithms (precessing and/or tumbling targets can be modeled). This propagation is required to enable the heating algorithms to properly model environmental interactions. After the internal motion and heating algorithms have propagated the target to the desired state, the trajectories are reinitialized to conform to user specified trajectory inputs to ensure synchronization between the internal and external trajectory drivers.

OPTISIG contains six pairs of clear/cloudy earthshine spectra for a variety of seasons and geographical locations. The earthshine spectra are used to calculate the heating flux from earthshine and earthshine reflection. OPTISIG employs a uniform cloud cover and a time-of-year varying solar flux. The atmosphere is divided into three regions from ground level to upper troposphere. OPTISIG allows the user to specify the distribution of clouds between the three regions. Atmospheric property tables up to 300 km altitude from 33 standard atmosphere models are included in the code for reentry calculations. These atmosphere models are the same as those used in the Optical Signatures Code (OSC). The atmosphere model is user-selectable in OPTISIG.

OPTISIG uses two thermal response algorithms corresponding to exoatmospheric and endoatmospheric conditions. For low flux or thin target cases, a one-layer solution to the linearized heat equation is used. For thick bodies or high flux situations, a multi-layer finite difference solution is used. The transition in high flux cases is performed automatically the first time the heat flux exceeds 2,500 W/m2. OPTISIG uses either roll-averaged or instantaneous flux calculations for precessing or tumbling targets. Target models developed prior to the release of OPTISIG 6.0 are limited to the use of roll-averaged flux calculations.

Target models with azimuthal thermal subdivisions can be constructed to take advantage of either the roll-averaged or instantaneous flux algorithms. OPTISIG can model internal and external radiation exchange, assuming graybody diffuse interactions. Targets with internal structures and non-axisymmetric paint schemes on spherical targets can also be modeled by OPTISIG.

1-3

Signatures for as many as 16 wavebands can be obtained using OPTISIG, which computes both emitted and reflected signature components. (Many stated limitations, such as number of bands, can be adjusted by changing parameter statements within OPTISIG. Refer to the source code for details.) In-band directional reflectance profiles are utilized in emitted signature calculations, and source weighted in-band directional reflectance profiles are employed in all reflection calculations. Optical properties used by OPTISIG are taken from the OSC directional reflectance database.

OPTISIG contains special algorithms for the generation of fragment signatures. Internally, fragment objects are modeled as cylinders with flat end caps. Cylinder dimensions are derived from user shape or projected area requirements or from default parameters contained in the TML. Details of the fragment shape inputs are contained in Section 4.3.5.

In addition to shape inputs, the user can specify each fragment’s initial temperature, solar absorptivity, and thermal emissivity on each side of the fragment, as well as the material thickness. Thermal environments are calculated using tumble averaged sun, earth, and albedo fluxes in the exoatmosphere with the addition of free molecular heating in the high endoatmosphere. Fragment temperatures are calculated by the use of an analytical two-layer solution to the linearized heat conduction equation. Directional optical data is not available in the TML, since the user must provide surface emissivity values; consequently, OPTISIG uses a Fresnel directional profile for emissive area calculations and assumes a real index of refraction equal to 1.1. Reflections from fragments are calculated using hemispherical reflectivities. The user specifies a fragment object in OPTISIG by supplying the fragment TNAME corresponding to the desired fragment material. Specific fragment parameters such as shape, thickness, optical properties, and initial temperature are communicated to OPTISIG through optional COMMON block FRGDEF (see Section 4.3.5).

OPTISIG has been verified to the OSC for target classes of interest. In the exoatmosphere, a deviation for RVs and thermally light objects are typically near two percent for self-emitted components and three percent for total signature.

2-1

2. Software Overview

2.1 Availability

Executables for the TIGER and OPTISIG software are distributed on CD with versions for

Windows and LINUX platforms. If you require OPTISIG or TIGER object files for linking to your own driver system, contact user support at TBE.

Current OPTISIG TMLs are classified by the sponsoring DOD program office and may be acquired by the user by contacting the appropriate sponsoring DOD program.

2.2 Computer Requirements

TIGER and OPTISIG are written in ANSI Standard FORTRAN 77, enabling their use on a wide variety of computers. The TML is stored in ASCII format for easier portability. OPTISIG and

TIGER are compiled with specific options for certain compilers, as described in the OSC and

OPTISIG Users’ Seminar briefings pertaining to compiling the software. Nearly all REAL variables and FUNCTION subprograms are declared DOUBLE PRECISION in the source code.

OPTISIG object files are provided to some projects. Users who receive object files (e.g., Linux

.so files) should refer to the specific documentation provided with each package.

2.3 User Responsibilities

Users can access TIGER and OPTISIG through the WinOSC GUI or the standalone executables provided on the CD. Users may also employ an engagement simulation program that includes OPTISIG and all its subroutines. Threat tapes may be used to derive initial target state vectors for the engagement simulation. Each target must be “flown forward” to the desired sensor observation time, then at this time, OPTISIG is called to provide a signature. The user must also propagate one or more sensor trajectories. Figure 2-1 shows the relationship of the engagement simulation program to the OPTISIG software.

Program TIGER runs independently of the engagement simulation program. The user inputs the proper TML and inputs the sensor wavebands of interest. TIGER integrates stored OSC spectral optical material data and writes out a file that is usable by OPTISIG. TIGER can also extract target models from up to four different TMLs and merge them into a customized STL.

2-2

Inputs to OPTISIG from the engagement simulation program are made via an argument list and COMMON blocks. The argument list contains parameters that identify the target, give its state vector at a particular time, and specify the sensor position. The argument list also includes options for controlling the reflective component and the printer output. Detailed information on this argument list is given in Section 4.2. COMMON blocks contain information on target dynamics, target dynamics options, initial temperature, environmental data, and fragment definition. Required and optional COMMON blocks are described in detail in Section 4.3.

2-3

User Input:

Target

Selection

Scenario Target Library Program

User Input:

• Waveband(s)

• Sensor Response

Target Integrator Program

In-Band

STL

(Binary)

The User’s OPTISIG Driver

TNAME/Index Cross

Reference

(ASCII)

OPTISIG 6.0

• Intensity in each waveband

• Random draws of object on first scan

• Time, altitude, aspect, range

User Provided Input:

• In-band STL binary file name

• Target state vector file name

• Sensor position

• Target type (ID)

• Target parameter distributions

• Environmental parameters

• Output file name

Trajectory Files (Target Boost Phase State Vectors) Output Files

MASTER.LIB

Scenario Target

Library (STL)

(ASCII)

TML

(ASCII)

(TIGER Program)

Figure 2-1: Functional Flow Diagram of OPTISIG

3-1

3. Program TIGER

TIGER (Target InteGRator) is an interactive front-end program to OPTISIG. TIGER accepts interactive input concerning the target library and the sensor wavebands. TIGER performs two functions: first, it extracts targets, by name, from target libraries and inserts them into the user’s scenario library; second, it processes the scenario for use with OPTISIG. TIGER integrates OSC spectral directional reflectance data into in-band directional emissivity profiles and source weighted in-band directional reflectance profiles. It then produces an output file that can be used directly by OPTISIG. The user has the option of inputting their own spectral response function for each waveband for use in OPTISIG calculations.

3.1 TIGER Inputs

When TIGER is executed, the first prompt asks for the function TIGER is to perform; either create or integrate an STL. If no STL has been created, the user must select option one and create one. TIGER asks for the number of target libraries to be extracted (four maximum).

Next, TIGER asks the user for the name of the TML from which targets are to be extracted.

The user is required to enter the number of targets to be extracted and the names of the targets to be extracted. Following this input, TIGER prompts the user for an STL identifier that will appear on the OPTISIG printout for user reference. At this point the user enters the file name of the scenario library and the name of the cross reference file. The cross reference file specifies which index of the COMMON block USRDYN is associated with each target (TNAME). It is important to note that the cross reference file information is required if the user intends to override the default dynamics of the targets selected for the STL. After all inputs are completed, TIGER creates the STL and returns the user to the option menu.

The first prompt of the scenario library integration asks for the number of wavebands to be input (up to four). This is followed by a request for the lower and upper limits of each waveband (in m) that may range between 0.3 and 30.0 m. Following a prompt for a waveband, TIGER asks the user if a spectral response function is desired for that band. If so, the spectral response function is requested as an ASCII file containing a single wavelength/response function pair on each record. The wavelengths must be specified in microns and the response function should be normalized to a maximum value of one.

Finally, TIGER asks for the file name of the STL (ASCII) to be integrated and the name of the

3-2 integrated STL (binary). File names may not exceed 256 characters. Following completion of inputs the program returns to the main menu. Section 3.3 contains a sample screen sequence during a user session with TIGER.

3.2 TIGER Error Messages

The following error messages may appear during TIGER execution:

1) Number of bands requested exceeds parameter statement dimension.

Program halted.

2) Error opening input target model library. Execution stopped.

3) Error opening output target model library. Execution stopped.

4) Target name not found. Reenter or abort.

3.3 Sample Screen Sequence for TIGER Session

Figure 3-1 shows a typical screen sequence for an interactive session with TIGER.

* TARGET LIBRARY PROGRAM *

* FOR OPTISIG 7.4.1 *

SELECT OPTION :

1 - BUILD USER SCENARIO TARGET LIBRARY

2 - BUILD SCENARIO THERMAL SCRIPT FILE

3 - PERFORM TARGET INTEGRATION

4 - QUIT AND EXIT

* TARGET LIBRARY EXTRACTION *

* FOR OPTISIG 7.4.1 *

ENTER NUMBER OF LIBRARIES FOR TARGET EXTRACTION :

ENTER NAME OF TARGET LIBRARY NUMBER 1

BESYSTEM.LIB

PLEASE BE PATIENT - ANALYZING LIBRARY :

BESYSTEM.LIB

* BE TMD SYSTEMS LIBRARY FOR OPTISIG 4.0 BETA 1

6 TARGETS

0 FRAGMENT TYPES

ENTER NUMBER OF TARGETS TO BE EXTRACTED FROM : BESYSTEM.LIB

ENTER 'ALL' TO EXTRACT ALL TARGETS :

ENTER NAME OF TARGET TO BE EXTRACTED FROM :

BESYSTEM.LIB

TARGET 1 IDENTIFIER CODE :

SYSC

TARGET 2 IDENTIFIER CODE :

SYSERV

3-3

TARGET 3 IDENTIFIER CODE :

SYSFRV

ENTER LIBRARY IDENTIFIER FOR OPTISIG PRINTOUT :

This is a test library with 3 targets

ENTER FILE NAME OF NEW LIBRARY :

THREETARG.LIB

ENTER FILE NAME FOR TARGET CROSS REFERENCE OUTPUT :

THREETARG.REF

PLEASE BE PATIENT ... CREATING LIBRARY :

THREETARG.LIB

* TARGET LIBRARY PROGRAM *

* FOR OPTISIG 7.4.1 *

SELECT OPTION :

1 - BUILD USER SCENARIO TARGET LIBRARY

2 - BUILD SCENARIO THERMAL SCRIPT FILE

3 - PERFORM TARGET INTEGRATION

4 - QUIT AND EXIT

* -- TIGER -- *

* TARGET INTEGRATOR PROGRAM *

* FOR OPTISIG 7.4.1 *

ENTER NUMBER OF WAVEBANDS :

ENTER LOWER, UPPER WAVEBAND LIMITS (MICRONS) :

BAND 1 :

4.0,6.0

DO YOU WANT TO USE A FILTER FUNCTION (1=YES) :

BAND 2 :

9.0,11.0

DO YOU WANT TO USE A FILTER FUNCTION (1=YES) :

ENTER NAME OF TARGET LIBRARY TO BE INTEGRATED :

THREETARG.LIB

ENTER NAME OF OUTPUT FILE :

THREETARG.INT

IS THERE A AUXILARY THERMAL SCRIPT FILE (1=YES):

* TARGET LIBRARY PROGRAM *

* FOR OPTISIG 7.4.1 *

SELECT OPTION :

1 - BUILD USER SCENARIO TARGET LIBRARY

2 - BUILD SCENARIO THERMAL SCRIPT FILE

3 - PERFORM TARGET INTEGRATION

4 - QUIT AND EXIT

Figure 3-1: Sample Screen Sequence for TIGER Session

4-1

4. Subroutine OPTISIG

OPTISIG consists of the executive subroutine OPTISIG and 97 subprograms (subroutines and functions). The user must resolve any conflicts with subprogram names and COMMON blocks in the driver program. Table 4-1 lists the subprogram names and gives a brief description of each subprogram, and Table 4-2 lists the COMMON block names used by

OPTISIG.

Table 4-1: Access Software Subprogram Summary

Title Description

SUBROUTINE AIR Returns the atmospheric density, temperature, and pressure as a function of altitude.

SUBROUTINE ALBENV Computes albedo environment.

SUBROUTINE ANGREC Converts between angular and rectangular. celestial equatorial coordinates

SUBROUTINE ATMMOD Initializes atmosphere model

SUBROUTINE BALDYN Calculates BALLIS dynamics.

SUBROUTINE BDYDYN Calculates the target post boost dynamics.

SUBROUTINE BDYINT Initializes target attitude and dynamics. Performs statistical draws for the body dynamics calculations.

SUBROUTINE BNDINT Integrator for Planck radiance tables.

SUBROUTINE BODASC Interpolates the ascent trajectory.

SUBROUTINE BODCAL Calculates the target trajectory.

SUBROUTINE BODVEC Converts Ballis style angles into ECI body unit vectors

SUBROUTINE CENTRD Initializes thermal station geometric variables

SUBROUTINE CEQER Celestial equatorial-to-Earth-rotational conversion.

SUBROUTINE COORD Computes a coordinate system based on two input vectors.

SUBROUTINE CROSSN Calculates the unit vector cross product of two input vectors.

SUBROUTINE DBDT Time derivative of body axes.

SUBROUTINE DEPRAN Performs statistical draws from selected statistical distributions.

SUBROUTINE DIFUSE Diffuse reflection algorithm (patched targets).

SUBROUTINE DIPREF Convective flow field algorithm for ascent and reentry heating

SUBROUTINE DIREPS Calculates the directional emissivity for a given angle.

SUBROUTINE DOSHAP Initialization for DIPREF flow field algorithm

FUNCTION DOT Computes the dot product of two vectors.

SUBROUTINE DWDT Time rate of change of angular velocity.

SUBROUTINE DYNAMO General rigid body dynamics driver.

SUBROUTINE ECIAXU Initializes facet model orientation (patch algorithm).

SUBROUTINE EINT Interpolates earthshine data.

SUBROUTINE ENVIR Computes roll-averaged solar, albedo, and earthshine fluxes.

SUBROUTINE EPOCH Calculates right ascension and declination.

SUBROUTINE ESHINE Calculates inband earthshine.

SUBROUTINE EULER Performs an Euler transformation.

SUBROUTINE EVENT Sequences ascent events.

SUBROUTINE FIXB Orthogonalizes body axes.

SUBROUTINE FLIN Interpolates external heat flux histories.

4-2

Title Description

FUNCTION FMCB A free molecular convective heating bridging relation.

FUNCTION FPFACT Computes Earth visibility factor

SUBROUTINE FRGINT Fragment initialization.

SUBROUTINE FRHEAT Fragment heating driver.

SUBROUTINE FRLIT Calculates fragment emissive signature.

SUBROUTINE FRREFL Calculates fragment reflective signature.

SUBROUTINE GETBOD Interpolates boost phase body attitude

SUBROUTINE GETITP Converts target name to target index.

SUBROUTINE GETPHI A utility called by SNDF.

SUBROUTINE GETTDP Retrieves deployment time from thermal initialization file

FUNCTION GMST Sidereal time at Greenwich.

SUBROUTINE HEADER Inserts legal disclaimer notice in output.

SUBROUTINE HEAT Drives the thermal response calculations.

SUBROUTINE INDPTH Performs multi-layer thermal response calculations.

SUBROUTINE INITIA Environment, radiance table, and model file initialization.

SUBROUTINE INV3 Inversion routine for 3x3 matrix.

SUBROUTINE JULIAN Calculates Julian day.

SUBROUTINE KPINIT Calculates orbital parameters.

SUBROUTINE LAYER Computes fragment indepth thermal layering

SUBROUTINE LENGTH Computes body centroid (distance from the nose assuming solid volume)

SUBROUTINE LIGHT Calculates radiant intensity.

SUBROUTINE LINE Finds the length of a line segment that is common to two given line segments.

SUBROUTINE MDLFIL Reads the input target model file.

SUBROUTINE NOSTIP Calculates the area fraction of a nosetip that is visible along the sensor line of sight.

FUNCTION NUMCH Returns the number of non-blank characters in a string

SUBROUTINE OBSC Performs target visibility calculations in the sensor viewing coordinate system.

SUBROUTINE OPTCOS Calculates average sensor-to-target cosines.

SUBROUTINE OPTSIG Main driver program.

SUBROUTINE PERPX A utility subroutine called by SNDF.

SUBROUTINE PLANCK Interpolates the blackbody radiance table.

SUBROUTINE PLIMS A utility subroutine called by SNDF.

SUBROUTINE PRTOUT Writes output to file.

SUBROUTINE QUARTK Finds the real roots of quartic polynomial.

SUBROUTINE RADTBL Generates the blackbody radiance tables.

SUBROUTINE RAINT Blackbody radiance integrator.

SUBROUTINE GRANGE Calculates ground range.

FUNCTION RANX Machine-independent uniform random number generator.

SUBROUTINE RAVCOS Returns a roll-averaged cosine.

SUBROUTINE RBIDIR BRDF stub routine

SUBROUTINE RDISC Computes the reentry heat flux on a one- or two-sided disc.

SUBROUTINE REFALB Calculates albedo reflected areas.

SUBROUTINE REFERT Calculates earthshine reflected areas.

SUBROUTINE REFSUN Calculates solar reflected areas.

SUBROUTINE RESOLI Resolved imagery stub routine

SUBROUTINE SETRAN Initializes random number generator.

SUBROUTINE SLVC A utility subroutine called by SNDF.

SUBROUTINE SOLFRA Calculates inband solar fraction.

4-3

Title Description

SUBROUTINE SPECUL Specular reflection algorithm (patch algorithm).

SUBROUTINE SUNINT Computes Sun location.

SUBROUTINE SUNLOC Computes Sun location.

SUBROUTINE TABBRD BRDF stub routine

SUBROUTINE TABSCR Reads thermal script information from integrated target library

SUBROUTINE THERMI Reads temperatures from existing temperature input file

SUBROUTINE THERMO Creates temperature data file and overwrites existing file

SUBROUTINE THRSP

FUNCTION TLIN

Performs the single-layer thermal response calculations.

Performs a linear interpolation on in-depth temperature data points.

SUBROUTINE TMPHIS Interpolates thermal history for a given station

SUBROUTINE TMPIN Reads in target surface temperatures

SUBROUTINE TMPINT Initializes target temperature.

SUBROUTINE TMPOUT Writes out target surface temperatures

SUBROUTINE TWOLAY Two-layer thermal response algorithm for fragments.

SUBROUTINE UNIT Returns a unit vector from an input vector.

SUBROUTINE VELDYN Calculates target boost dynamics.

SUBROUTINE WALFLX Calculates imposed external heatflux

FUNCTION YLIN Performs a linear interpolation on beta profile data points.

Table 4-2: COMMON block names used by OPTISIG

AIRDEN ALB ALB0 ALBDAT ALBVAL

ANGLES ASCTRJ ASSTEP BETA BIDIRC

BODYDY CLOUDS CMDIST DEEP DIPSHP

DYNO ENVIRO ETFRG FACTAR FILES

FLAGS FORDIP FRGDEF FRGLIB GAUSQD

GIJ HTFLX HTFLX0 HTFLXI IHTFLX

INTTR MATOP MICDYN MODEL MOOCOW

RA RADTMP RANSHF REENT REF

RENTRY RESGEO RESOLV ROLL RUNOPT

SEALVL SEED SENTRJ SHROUD SIM

SOLDAT SURTMP TARGET TENV TGTRAJ

THRMIN THRMIO TIMES TINCOM TLAYER

TMHISC TRAJIC USRAXS USRDYN USRINP

XVIN ZCONST ZPLANK ZSIGS

4.1 OPTISIG Top-Level Functional Flow

OPTISIG is designed to return a threat object’s radiant intensity at a given time upon a call to

OPTISIG. The user is responsible for scheduling OPTISIG as frequently as desired to update a target’s signature.

Figure 4-1 presents a simplified top-level flow of OPTISIG execution. Upon the first call to

OPTISIG, environment initialization is performed and the integrated TML file (TIGER’s output)

4-4 is read and stored in memory. Upon the first call for a given target ID/TNAME, OPTISIG propagates the target state vector to deployment (DPLOYT). Target metric and thermal parameters are initialized on the first call for each target and updated on subsequent calls.

The program proceeds to propagate the target to the current simulation time. During this process, it updates the target orientation and dynamics, calculates the thermal response of the target and updates the target temperatures. After updating the target temperatures to the current simulation time (TIMNOW), signatures are calculated and returned to the user through the calling argument.

Figure 4-1: OPTISIG Top-Level Flow Diagram

Two procedures are available for running OPTISIG. The first procedure, used primarily for discrimination studies, allows the user to select and run a target for the entire trajectory of interest. The user can either use this data, or save the data, and then select a new target

OPTISIG

Read in Integrated

Target Model Library

Propagate Trajectory and

Target Thermal Response to

Current Simulation Time

Random Picks for Coning

Angle, Spin Rate, Angular

Momentum Orientation

Initialize Target and Fly from State Vector to

Deployment

Calculate

Signatures

Return

First

Call to

OPTISIG

First

Call for

Target

User

Driven

Dynamics

T

F

T

F Y

NO

4-5 identifier and obtain data for that target. The second procedure is used primarily in system simulations. The user selects a target, propagates the trajectory, and gets the signature at a single time. This process is repeated for the additional targets of interest before completing the signature of the first target. The user may use this method to obtain signatures of a threat complex of objects in a sensor’s field-of-view.

OPTISIG may be used in multiple sensor simulations by calling OPTISIG at the appropriate sensor observation times with the appropriate sensor state vector calling arguments.

Currently, OPTISIG can track up to 5000 targets simultaneously. Larger simulations may be accommodated by using the simulation reset feature, IRESET (see Table 4-3).

4.2 OPTISIG Operation

A user-supplied program is required to interface with OPTISIG by a combination of subroutine calling arguments and COMMON block inputs. The COMMON block inputs define initial environmental and target dynamics information. Most calling arguments represent time-varying quantities that the external simulation must produce and pass to OPTISIG.

These quantities include the current simulation time, target ECI position and velocity, sensor

ECI state vector, and target deployment time. OPTISIG returns the target to sensor aspect angle and radiant intensities in up to four wavebands at the current simulation time. Other arguments control reflected signature calculations and printer output options.

Two key calling arguments (ID and TNAME) uniquely specify a target in OPTISIG. The object identifier (ID) is an integer between one and the maximum number of objects in a threat complex. The target name (TNAME) is a character identifier key that selects a given threat object class from the input STL. The target names are described in a separate TML description manual.

The FORTAN calling statement to OPTISIG is shown in Figure 4-2.

CALL OPTSIG (IRESET, ID, TNAME, X, V, SPOS, TIMNOW, DPLOYT, IREFL, IPRINT,

IUNIT, ASPA, SIGS, OPTI_STATUS)

Figure 4-2: FORTAN Calling Statement for OPTISIG

4-6

The arguments are defined in Table 4-3, with array dimensions as shown. The six-letter program name, OPTSIG, is used to adhere to ANSI standard FORTRAN 77 naming conventions. OPTISIG does not modify the input arguments in any way.

Table 4-3: Arguments for SUBROUTINE OPTISIG

Argument Units Variable Type Description

INPUTS

IRESET INTEGER Resets simulation by purging previous target IDs. Reset does not normally reinitialize the random number generator. Must only be set to (1) once and reset to (0) on the following call. Generally used for running a number of targets larger than array and variable allocations. Should normally be left at (0) unless running a very large number of targets. IRESET = 2 will reset the random number sequence in addition to purging all targets.

ID INTEGER Object identifier number between 1 and the maximum number of objects in the threat. New ID values may be input in any order.

TNAME CHARACTER*10 Target name for given object identifier. The values correspond to the target names in the TML Reference Manual appropriate for the library that is being used.

X(3) m REAL Target ECI position vector.

V(3) m/sec REAL Target ECI velocity vector.

SPOS(3) m REAL Sensor ECI position vector.

TDPLOY sec REAL Thermal calculation start time.

TIMNOW sec REAL Current simulation time.

IREFL INTEGER Zero (0) calculates and returns only the emissive component of the signature. One (1) calculates contribution from the emissive and reflective components. Note for ultraviolet/visible wavebands IREFL must be set (1).

IPRINT INTEGER Zero (0) turns off full target output. One (1) turns on full target output. Regardless of switch setting all error message will be written to the output file specified by (IUNIT).

IUNIT INTEGER File that output is written to. Six (6) is standard printer output file.

OUTPUTS:

ASPA deg REAL Sensor to target aspect angle.

SIG(16)

OPTI_STATUS

W/sr REAL

INTEGER

Output radiant intensity in each band (up to 16).

Status flag

4.3 OPTISIG Common Block Requirements

Two COMMON blocks are required for input to OPTISIG; eight other COMMON blocks are optional. These FORTRAN COMMON statements must appear in the user’s engagement program and the values of the parameters must be defined prior to the first call to OPTISIG.

4-7

4.3.1 Required COMMON Block 1 (FILES)

CHARACTER*80 MODFIL

COMMON/FILES/MODFIL

MODFIL: The name of the integrated TML file OPTISIG will use is passed into OPTISIG through the character variable MODFIL in the COMMON block FILES. In order to avoid file conflict, it is important to note that the target model file is read in through unit 40 and that this unit should be reserved for the use of OPTISIG.

4.3.2 Required COMMON Block 2 (USRINP)

COMMON/USRINP/ QSEED, HOUR, REFLON, TMISS, CLDCVR, CLFRAC(3), IATMOS, IEARTH,

IMONTH, IDAY, IYEAR, IDYOPT(42), ITPOPT(42), IASOPT(42) *,IFLOW(42), IOBLAT, ICLOUD

QSEED: QSEED sets the seed for random number generation. Users can obtain the same random picks on different runs by setting seed to the same value.

Changing the seed’s value will result in different random picks. OPTISIG uses machine independent software algorithm for generating random numbers, assuring the same results on all types of computers.

HOUR: The hour (0-24) is entered as its decimal equivalent (1:15 pm = 13.25).

REFLON: Reference longitude for local time (HOUR). The HOUR in the previous input is defined as the time at the given reference longitude on IMONTH and IDAY. The reference longitude is entered in degrees East. Longitudes west of the

Greenwich meridian may be entered as negative values (-105 = 255).

TMISS: Mission time (seconds) of sun position definition. Sun position due to earth rotation is calculated relative to this time.

CLDCVR: The cloud cover percentage is entered as a decimal fraction between zero and one, inclusive. For example, 55% cloud cover is entered as 0.55. OPTISIG assumes uniform cloud map conditions over the whole earth scene.

The index of array elements IDYOPT, ITPOPT and IASOPT refer to the target index associated with the target

TNAME. A cross reference listing of TNAMES and indices is provided as output from the Program TIGER.

4-8

CLFRAC: OPTISIG contains earthshine data corresponding to cloud tops at three altitudes: 1/3, 2/3, and 1 tropopause altitudes. The cloud composition at each of the three altitudes is entered as a percentage, with the total being 100%.

IATMOS: Thirty three atmosphere models are available in OPTISIG: These models tabulate atmospheric pressure, density, and molecular temperatures up to 300 km.

To select the atmosphere model, use the values for IATMOS in Table 4-4.

Table 4-4: Atmosphere Models (IATMOS)

IATMOS Atmosphere Model

1 TROPICAL + NASA GRAM

2 MIDLATITUDE SUMMER + NASA GRAM

3 MIDLATITUDE WINTER + NASA GRAM

4 ARCTIC SUMMER + NASA GRAM

5 ARCTIC WINTER + NASA GRAM

6 SSGM EQUATORIAL (0) JULY + NASA GRAM

7 SSGM EQUATORIAL (0) JAN + NASA GRAM

8 SSGM TROPICAL (15) JULY + NASA GRAM

9 SSGM TROPICAL (15) JAN + NASA GRAM

10 SSGM TROPICAL (15) + NASA GRAM

11 SSGM SUBTROPICAL (30) JULY + NASA GRAM

12 SSGM SUBTROPICAL (30) JAN + NASA GRAM

13 SSGM MIDLATITUDE SUMMER + NASA GRAM

14 SSGM MIDLATITUDE WINTER + NASA GRAM

15 SSGM MIDLAT SPRING/FALL + NASA GRAM

16 SSGM SUBARCTIC (60) SUMMER + NASA GRAM

17 SSGM SUBARCTIC (60) WINTER + NASA GRAM

18 SSGM SUBARCTIC JAN WARM A + NASA GRAM

19 SSGM SUBARCTIC JAN WARM B + NASA GRAM

20 SSGM SUBARCTIC JAN WARM C + NASA GRAM

21 SSGM SUBARCTIC JAN COLD D + NASA GRAM

22 SSGM ARCTIC SUMMER JULY + NASA GRAM

23 SSGM ARCTIC WINTER JAN + NASA GRAM

24 SSGM POLAR SUMMER JULY + NASA GRAM

25 SSGM POLAR WINTER JAN + NASA GRAM

26 SSGM 1976 U.S. STANDARD + NASA GRAM

27 SSGM ISRAELI STANDARD DAY + NASA GRAM

28 SSGM ISRAELI STANDRD NITE + NASA GRAM

29 BEAML-99 LOWER DENSITY PROFILE (DIA/MSIC)

30 BEAM-99 MEDIAN DENSITY PROFILE (DIA/MSIC)

31 BEAMU-99 UPPER DENSITY PROFILE (DIA/MSIC)

32 1962 U.S. STANDARD

33 1976 U.S. STANDARD

4-9

IEARTH: Six earthshine models may be chosen for a range of seasons and latitudes.

Earthshine spectra tables are tabulated from LOWTRAN 6 for clear and one third tropopause cloudy conditions. The models, months of validity, and latitude ranges are shown in Table 4-5.

Table 4-5: Earthshine Models (IEARTH)

IEARTH Model Months Latitude Range (deg)

1 US62 3-5, 9-11 -90 to 90

2 TROPICAL 1-12 -25 to 25

3 MIDLATITUDE WINTER 1, 2, 12 25 to 55

4 MIDLATITUDE SUMMER 6, 7, 8 25 to 55

5 ARCTIC WINTER 1, 2, 12 >55

6 ARCTIC SUMMER 6, 7, 8 >55

IMONTH: The month is entered as an integer number between 1 and 12.

IDAY: The day refers to the day of the month (1-31).

IYEAR: The year is entered as an integer (e.g., 1991).

The inputs IMONTH, IDAY, HOUR, IYEAR, TMISS, and REFLON are used to compute the sun’s position.

IDYOPT: OPTISIG provides the user with four options for the handling of target dynamics for each type of target. Option one (built into each TML file) is a set of distribution parameters used for random picks on target dynamics and initial temperature. These default parameters can be found in the Target Model

Library Description Manual. By setting IDYOPT to 2 or 3, the user can override the default values for the distribution parameters by providing an additional

COMMON block (USRDYN). The fourth option, achieved by setting IDYOPT equal to 4, enables the user to drive the target dynamics by general rigid body motion.

This option allows the user to have total control over the target attitude at the requested signature time. The user provides the current target body axis, angular rates and the body inertia tensor (on every call to OPTISIG) through

COMMON block MICDYN. This allows the general rigid body dynamics driver in

OPTISIG…