CTM-Definitions-List_-_All_Categories--2013.07.16.pdf

All Categories - Definition List (DRAFT) Taxonomy Code CTM Term

Definition Additional Details

Definition Reference(s)

Signatures - Definition List (DRAFT) S Signatures

A distinctive type of radiation emitted and/or reflected by man-made objects such as threat/target/interceptor/airbreather hardbody/plume configurations of interest.

In the context of Core Truth Models the perceivable energy is considered to be of an electromagnetic nature that can be observed by MDA radio frequency (RF), electrooptical (EO), and infrared (IR) sensors and seekers. The predicted properties of this energy are determined at the source (at source) after the threat/target/interceptor/airbreather has been illuminated by any active RF/EO/IR devices and prior to the transmission of that energy to observing sensors and/or seekers. Similarly, the properties of this energy are established at the source before it passes through space and/or the atmosphere to any passive EO/IR sensors/seekers.

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- Truth Conceptual Modeling Briefing, Ricardo Parks, 10 January 2013, Slide #2.

- MSEWG Consistent Truth Implementation Tiger Team (CTITT) Briefing, 3 April 2013, Slide #7.

- MDA Glossary, VER. 4.0, https://mko.mda.mil/sites/training/SiteCollectionDocuments/MDA%20Glossary.pdf.

S 1 Plume EO/IR

The spectral and in-band, electrooptical (EO) and/or infrared (IR), point-source and/or extended, signatures emitted by exhaust plumes of interest.

Exhaust plumes of interest include missile launch, boost, staging, post-boost vehicle (PBV), divert attitude control system (DACS), attitude control motor (ACM), airbreather (cruise missile), etc. propulsive flows. Their EO/IR signatures are functions of propellant formulation, oxidizer/fuel (O/F) ratio [for liquid engines], combustion efficiency, trajectory, angle-of-attack, Mach number, altitude, propulsion system design, and geometry.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, April 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 1 of 83Content Updated: 2 Jul 2013

Definition

Additional Details Definition Reference(s)

S 1.1 Low Altitude (Continuum)

The altitude regime in which the atmosphere behaves as a continuous material.

The continuum assumption is valid when the mean free path of the molecules in the atmosphere is less than a characteristic dimension of the exhaust plume of interest. It is identified by the ratio of the mean free path to the characteristic dimension, termed the Knudsen number (Kn). Although this ratio depends on the thrust of the rocket engine/motor and the specific properties of each exhaust plume, a notional value of Kn < 0.01 can be considered to identify the continuum flow regime. The lower limit of continuum flow is sea level while the upper limit varies from roughly 70km to 150km, depending on the thrust of the engine/motor.

Exhaust plumes that typically operate in the low altitude regime include missile launch, boost, staging, post-boost vehicle (PBV), divert attitude control system (DACS), attitude control motor (ACM), and airbreather (cruise missile) propulsive flows.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- Modern Compressible Flow with Historical Perspective, 3rd Edition, John D. Anderson, McGraw-Hill, New York, NY, 2003, pp.18-19.

- The Dynamics and Thermodynamics of Compressible Fluid Flow, Ascher H. Shapiro, The Ronald Press Company, New York, NY, 1953. pp. 4-5.

- Rocket Exhaust Plume Phenomenology, Frederick S. Simmons, The Aerospace Press, El Segundo, CA, 2000, pp. 26-29.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, April 2013.

S 1.2 High Altitude (Rarefied)

The altitude regime in which the atmosphere no longer behaves as a continuous material.

This flow is considered to be rarefied when the mean free path of the molecules in the atmosphere is the same order of magnitude as a characteristic dimension of the exhaust plume of interest. It is identified by the ratio of the mean free path to the characteristic dimension, termed the Knudsen number (Kn). Although this ratio depends on the thrust of the rocket engine/motor and the specific properties of each exhaust plume, a notional value of Kn > 0.1 can be considered to identify the rarefied flow regime. The lower limit of rarefied flow varies from roughly 270km to 400km, depending on the thrust of the engine/motor.

Exhaust plumes that typically operate in the high altitude regime include post-boost vehicle (PBV), divert attitude control system (DACS), and attitude control motor (ACM) propulsive flows.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- Modern Compressible Flow with Historical Perspective, 3rd Edition, John D. Anderson, McGraw-Hill, New York, NY, 2003, pp.18-19.

- The Dynamics and Thermodynamics of Compressible Fluid Flow, Ascher H. Shapiro, The Ronald Press Company, New York, NY, 1953. pp. 4-5.

- Rocket Exhaust Plume Phenomenology, Frederick S. Simmons, The Aerospace Press, El Segundo, CA, 2000, pp. 26-29.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, April 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 2 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 2 Hardbody EO/IR

The spectral and in-band, electrooptical (EO) and/or infrared (IR), point-source and/or extended, signatures emitted and reflected by solid bodies of interest.

Solid bodies of interest include missile stages, spent tanks, post-boost vehicles (PBVs), re-entry vehicles (RVs), kill vehicles (KVs), kinetic weapons (KWs), air breathers (such as cruise missiles), etc. of interest. Their EO/IR signatures are functions of structural composition, material heat capacities and reflective properties, internal heat sources, external heating, environmental irradiance, trajectory, angle-of-attack, Mach number, and altitude.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, April 2013.

S 2.1 Hardbody

A solid object such as a missile stage, spent tank, post-boost vehicle, re-entry vehicle, kill vehicle , kinetic weapon, dispensed submunition, air breather (i.e., cruise missile), etc. of interest that self-emits and/or reflects radiation energy.

EO/IR Perspective:

In the EO/IR region of the electromagnetic spectrum, hardbodies self-emit and/or reflect EO/IR radiation.

RF/RCS Perspective:

In the RF part of the electromagnetic spectrum, hardbodies generally reflect RF radiation.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, April 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 3 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 2.2 Countermeasures

Solid objects that serve to alter and/or mask the signature of a threat vehicle (such as an RV) to prevent its destruction by an intercepting kill vehicle of kinetic weapon.

EO/IR Perspective:

EO/IR countermeasures attempt to confuse observers of the spectral and/or in-band EO/IR signature of a threat vehicle.

RF/RCS Perspective:

RF/RCS countermeasures attempt to alter radar tracking and sensing behavior. Two examples are jammers and chaff, described below.

- Jammer - a passive or active device that blocks transmission or reception of signals, usually by creating some form of interference at the same frequency range.

- Chaff - an active induced environment ejected from a vehicle that contains strips of foil or clusters of fine wires. When illuminated by a radar, such lengths of metal resonate and re-radiate the signal. This results in the appearance of a secondary target cluster or the presence of multiple returns, which complicates or prevents detection and discrimination.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 2.3 Resident Space Objects (RSOs)

Satellites and their related launch debris that permanently orbit the earth and are therefore resident in the space surrounding the earth.

Orbital altitudes in which RSOs reside include low earth orbit (LEO), geosynchronous orbit, super-synchronous orbit, and beyond. Placing RSOs in orbit can produce debris that also orbits the earth. Such debris includes separation related debris (such as payload shrouds and V-bands), Payload Assist Modules (PAMs), Apogee Kick Motors (AKMs), payload deployment platforms, etc. The RSOs and their associated debris are cataloged in the Satellite Catalog (SATCAT) that is maintained by NORAD. As of 4/29/2013, the SATCAT contained more than 39,000 entries of which 3,700 were payloads and 13,100 were debris; only 1,166 of the entries were functional payloads.

Note: The SATCAT can be found at either http://celestrak.com/satcat/boxscore.asp and http://planet4589.org/space/logs/satcat.txt. Current as of 4/29/2013.

- MDA/EEV VV&A, CTM Environments Digital M&S Lead, J.R. Smith, 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 4 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 3 Nearbody EO/IR

The spectral and in-band, EO/IR, point-source and/or extended, signatures produced by body components and interactions that occur in proximity to but are not necessarily attached to hardbodies of interest.

Hardbodies of interest include missile stages, spent tanks, post-boost vehicles (PBVs), re-entry vehicles (RVs), kill vehicles (KVs), kinetic weapons (KWs), air breathers (such as cruise missiles), etc. Close-proximity body components include separation debris (such as shrouds, interstages, bands and "shard"), chuff, post-intercept debris, etc. Close-proximity EO/IR interactions include plumeshine, wakes, intercept flash, etc.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 3.1 Plumeshine

The enhancement of the hardbody spectral and in-band, EO/IR signature due to radiation emitted by exhaust plumes that is reflected off the hardbody.

Plumeshine becomes important as the size of an exhaust plume grows very wide in comparison to the hardbody, such as when a boosting missile reaches altitudes above 70km, depending on the thrust of the engine/motor.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 3.2 Separation Debris

Solid objects such as shrouds, interstages, bands, "shard", etc. that are jettisoned as a consequence of stage and payload separation during missile flight.

While separation debris may largely consist of the types of items listed above, it can also include spent upper stages and tanks, spin tables, and general debris.

Note that the term "shard" should be clarified here. This term was taken directly from slides 3 and 4 of the "BMDS Conceptual Modeling SCM Threat View" briefing presented to the MSWEG Conceptual Model Tiger Team by Jim Ceney on 15 February 2013. It occurs in the phrase 'separation "shard" debris' but is not explained.

Nonetheless, slide 4 of the presentation justifies inclusion of this type of separation debris on the basis that it is a "system stressor (to the 'invisible' size limit)".

Therefore, it can be inferred that "shard" refers to extremely small fragments or broken pieces of material created during separation events.

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA Glossary, VER. 4.0, https://mko.mda.mil/sites/training/SiteCollectionDocuments/MDA%20Glossary.pdf.

- BMDS Conceptual Modeling SCM Threat View briefing, Jim Ceney, 15 February 2013, Slides # 3-4.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 5 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 3.3 Chuff/Fuel Debris

Solid fuel debris, insulation, liner material, etc. from a solid rocket motor and/or nozzle material that is produced during the trust termination and/or burnout process of a solid rocket motor.

None.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 3.4 Wake

The plasma produced by the ionization of atmospheric gases along with the possible pyrolysis and/or ablation of a hardbody surface when the hardbody re-enters the atmosphere.

When a body such as an RV re-enters and descends into the atmosphere, tremendous heat is generated by aerodynamic friction between the RV and the increasingly dense atmosphere. This intense heat ionizes the surrounding atmospheric gases. It can also cause pyrolysis of painted surfaces and the ablation of body surface material. The result is a wake of ionized plasma that trails behind the RV.

EO/IR Perspective: A wake can be detected by EO/IR seekers, depending on the spectral band.

RF/RCS Perspective: A wake reflects radar pulses as does the RV itself.

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 3.5 Intercept Flash

The time-evolving plasma cloud resulting from a kinetic intercept of two or more bodies, such as a kill vehicle (or kinetic weapon) and an RV.

EO/IR Perspective: The time-varying EO/IR signature of an intercept flash is determined by its highly unsteady variations in temperature, expansion velocity, and chemical species concentration.

RF/RCS Perspective: The corresponding, effective RCS is derived from the rapid changes in expansion velocity and electron density.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 6 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 3.6 Post-Intercept Debris (PID)

The debris associated with the collision of a hit-to-kill interceptor with a target.

EO/IR Perspective: The EO/IR signatures produced by the post-intercept debris present in a scene are determined from the material properties, temperature, and projected area of each piece.

RF/RCS Perspective: The RF/RCS signatures are determined from the RCS of each large piece of debris along with RCS distribution statistics (including mean, max, and standard deviation) needed to populate CORS (CORrelated Statistical) representations of the small pieces.

- MDA/ESP Core Truth Models, Lethality Lead, William J. Black, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA/SN, M&S Technical Director, Dr. Eric Trees, April 2013.

- MDA Glossary, VER. 4.0, https://mko.mda.mil/sites/training/SiteCollectionDocuments/MDA%20Glossary.pdf.

- CORS RCS File Discussion, 13 Mar 2013, Slide #2.

S 3.7 Fuel Venting

The intentional and/or accidental release of liquid fuel into the atmosphere that creates a trail of radiating effluent.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- TRMP-T Database.

S 4 Plume RF/RCS

The radio frequency (RF) interference and radar cross section (RCS) signatures produced by exhaust plumes of interest.

Exhaust plumes of interest include missile launch, boost, staging, post-boost vehicle (PBV), divert attitude control system (DACS), attitude control motor (ACM), airbreather (cruise missile), etc. propulsive flows. Their RF/RCS signatures are functions of propellant formulation, particulate additives used to stabilize combustion and/or enhance specific impulse, combustion efficiency, trajectory, angle-of-attack, Mach number, altitude, propulsion system design, and geometry.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 7 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 4.1 Low Altitude (Continuum)

The altitude regime in which the atmosphere behaves as a continuous material.

The continuum assumption is valid when the mean free path of the molecules in the atmosphere is less than a characteristic dimension of the exhaust plume of interest. It is identified by the ratio of the mean free path to the characteristic dimension, termed the Knudsen number (Kn). Although this ratio depends on the thrust of the rocket engine/motor and the specific properties of each exhaust plume, a notional value of Kn < 0.01 can be considered to identify the continuum flow regime. The lower limit of continuum flow is sea level while the upper limit varies from roughly 70km to 150km, depending on the thrust of the engine/motor.

Exhaust plumes that typically operate in the low altitude regime include missile launch, boost, staging, post-boost vehicle (PBV), divert attitude control system (DACS), attitude control motor (ACM), and airbreather (cruise missile) propulsive flows.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- Modern Compressible Flow with Historical Perspective, 3rd Edition, John D. Anderson, McGraw-Hill, New York, NY, 2003, pp.18-19.

- The Dynamics and Thermodynamics of Compressible Fluid Flow, Ascher H. Shapiro, The Ronald Press Company, New York, NY, 1953. pp. 4-5.

- Rocket Exhaust Plume Phenomenology, Frederick S. Simmons, The Aerospace Press, El Segundo, CA, 2000, pp. 26-29.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, April 2013.

S 4.2 High Altitude (Rarefied)

The altitude regime in which the atmosphere no longer behaves as a continuous material.

This flow is considered to be rarefied when the mean free path of the molecules in the atmosphere is the same order of magnitude as a characteristic dimension of the exhaust plume of interest. It is identified by the ratio of the mean free path to the characteristic dimension, termed the Knudsen number (Kn). Although this ratio depends on the thrust of the rocket engine/motor and the specific properties of each exhaust plume, a notional value of Kn > 0.1 can be considered to identify the rarefied flow regime. The lower limit of rarefied flow varies from roughly 270km to 400km, depending on the thrust of the engine/motor.

Exhaust plumes that typically operate in the high altitude regime include post-boost vehicle (PBV), divert attitude control system (DACS), and attitude control motor (ACM) propulsive flows.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- Modern Compressible Flow with Historical Perspective, 3rd Edition, John D. Anderson, McGraw-Hill, New York, NY, 2003, pp.18-19.

- The Dynamics and Thermodynamics of Compressible Fluid Flow, Ascher H. Shapiro, The Ronald Press Company, New York, NY, 1953. pp. 4-5.

- Rocket Exhaust Plume Phenomenology, Frederick S. Simmons, The Aerospace Press, El Segundo, CA, 2000, pp. 26-29.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, April 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 8 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 5 Hardbody RF/RCS

The radio frequency (RF) interference and radar cross section (RCS) signatures produced by solid bodies of interest.

Solid bodies of interest include missile stages, spent tanks, post-boost vehicles (PBVs), re-entry vehicles (RVs), kill vehicles (KVs), kinetic weapons (KWs), air breathers (such as cruise missiles), etc. of interest. Their RF/RCS signatures are functions of structural composition, geometry (both internal and external), and relative view angle.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 5.1 Hardbody

A solid object such as a missile stage, spent tank, post-boost vehicle, re-entry vehicle, kill vehicle , kinetic weapon, dispensed submunition, air breather (i.e., cruise missile), etc. of interest that self-emits and/or reflects radiation energy.

EO/IR Perspective:

In the EO/IR region of the electromagnetic spectrum, hardbodies self-emit and/or reflect EO/IR radiation.

RF/RCS Perspective:

In the RF part of the electromagnetic spectrum, hardbodies generally reflect RF radiation.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, April 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 9 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 5.2 Countermeasures

Solid objects that serve to alter and/or mask the signature of a threat vehicle (such as an RV) to prevent its destruction by an intercepting kill vehicle of kinetic weapon.

EO/IR Perspective:

EO/IR countermeasures attempt to confuse observers of the spectral and/or in-band EO/IR signature of a threat vehicle.

RF/RCS Perspective:

RF/RCS countermeasures attempt to alter radar tracking and sensing behavior. Two examples are jammers and chaff, described below.

- Jammer - a passive or active device that blocks transmission or reception of signals, usually by creating some form of interference at the same frequency range.

- Chaff - an active induced environment ejected from a vehicle that contains strips of foil or clusters of fine wires. When illuminated by a radar, such lengths of metal resonate and re-radiate the signal. This results in the appearance of a secondary target cluster or the presence of multiple returns, which complicates or prevents detection and discrimination.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 5.3 Resident Space Objects (RSOs)

Satellites and their related launch debris that permanently orbit the earth and are therefore resident in the space surrounding the earth.

Orbital altitudes in which RSOs reside include low earth orbit (LEO), geosynchronous orbit, super-synchronous orbit, and beyond. Placing RSOs in orbit can produce debris that also orbits the earth. Such debris includes separation related debris (such as payload shrouds and V-bands), Payload Assist Modules (PAMs), Apogee Kick Motors (AKMs), payload deployment platforms, etc. The RSOs and their associated debris are cataloged in the Satellite Catalog (SATCAT) that is maintained by NORAD. As of 4/29/2013, the SATCAT contained more than 39,000 entries of which 3,700 were payloads and 13,100 were debris; only 1,166 of the entries were functional payloads.

Note: The SATCAT can be found at either http://celestrak.com/satcat/boxscore.asp and http://planet4589.org/space/logs/satcat.txt. Current as of 4/29/2013.

- MDA/EEV VV&A, CTM Environments Digital M&S Lead, J.R. Smith, 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 10 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 6 Nearbody RF/RCS

The radio frequency (RF) interference and radar cross section (RCS) signatures produced by body components and interactions that occur in proximity to but are not necessarily attached to hardbodies of interest.

Hardbodies of interest include missile stages, spent tanks, post-boost vehicles (PBVs), re-entry vehicles (RVs), kill vehicles (KVs), kinetic weapons (KWs), air breathers (such as cruise missiles), etc. Close-proximity body components include separation debris (such as shrouds, interstages, bands and "shard"), chuff, post-intercept debris, etc. Close-proximity RF/RCS interactions include multiple point scattering, enhanced RCS due to plume/hardbody coupling, wakes, intercept flash, etc.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 6.1 Multiple Point Scattering

The interaction of RF energy reflected by components of the body of interest that alters the resulting RCS from what would be predicted by the simple addition of the individual radar returns produced by each such component.

None.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 6.2 Enhanced RCS due to Plume/Hardbody Coupling

Enhancement of hardbody RCS due to highly nonlinear RF interactions between the body of interest and its associated exhaust plumes so that the resulting RCS cannot be accurately determined by simple addition of the individual body and plume radar returns.

None.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 11 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 6.3 RF Coupling Between Closely Spaced Objects

The interaction of RF energy between objects in close proximity to but not attached to the body of interest that alters the resulting RCS from what would be predicted by the simple addition of each object's individual radar return.

None.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 6.4 Separation Debris

Solid objects such as shrouds, interstages, bands, "shard", etc. that are jettisoned as a consequence of stage and payload separation during missile flight.

While separation debris may largely consist of the types of items listed above, it can also include spent upper stages and tanks, spin tables, and general debris.

Note that the term "shard" should be clarified here. This term was taken directly from slides 3 and 4 of the "BMDS Conceptual Modeling SCM Threat View" briefing presented to the MSWEG Conceptual Model Tiger Team by Jim Ceney on 15 February 2013. It occurs in the phrase 'separation "shard" debris' but is not explained.

Nonetheless, slide 4 of the presentation justifies inclusion of this type of separation debris on the basis that it is a "system stressor (to the 'invisible' size limit)".

Therefore, it can be inferred that "shard" refers to extremely small fragments or broken pieces of material created during separation events.

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA Glossary, VER. 4.0, https://mko.mda.mil/sites/training/SiteCollectionDocuments/MDA%20Glossary.pdf.

- BMDS Conceptual Modeling SCM Threat View briefing, Jim Ceney, 15 February 2013, Slides # 3-4.

S 6.5 Chuff/Fuel Debris

Solid fuel debris, insulation, liner material, etc. from a solid rocket motor and/or nozzle material that is produced during the trust termination and/or burnout process of a solid rocket motor.

None.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 12 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 6.6 Wake

The plasma produced by the ionization of atmospheric gases along with the possible pyrolysis and/or ablation of a hardbody surface when the hardbody re-enters the atmosphere.

When a body such as an RV re-enters and descends into the atmosphere, tremendous heat is generated by aerodynamic friction between the RV and the increasingly dense atmosphere. This intense heat ionizes the surrounding atmospheric gases. It can also cause pyrolysis of painted surfaces and the ablation of body surface material. The result is a wake of ionized plasma that trails behind the RV.

EO/IR Perspective: A wake can be detected by EO/IR seekers, depending on the spectral band.

RF/RCS Perspective: A wake reflects radar pulses as does the RV itself.

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

S 6.7 Intercept Flash

The time-evolving plasma cloud resulting from a kinetic intercept of two or more bodies, such as a kill vehicle (or kinetic weapon) and an RV.

EO/IR Perspective: The time-varying EO/IR signature of an intercept flash is determined by its highly unsteady variations in temperature, expansion velocity, and chemical species concentration.

RF/RCS Perspective: The corresponding, effective RCS is derived from the rapid changes in expansion velocity and electron density.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 13 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

S 6.8 Post-Intercept Debris (PID)

The debris associated with the collision of a hit-to-kill interceptor with a target.

EO/IR Perspective: The EO/IR signatures produced by the post-intercept debris present in a scene are determined from the material properties, temperature, and projected area of each piece.

RF/RCS Perspective: The RF/RCS signatures are determined from the RCS of each large piece of debris along with RCS distribution statistics (including mean, max, and standard deviation) needed to populate CORS (CORrelated Statistical) representations of the small pieces.

- MDA/ESP Core Truth Models, Lethality Lead, William J. Black, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA/SN, M&S Technical Director, Dr. Eric Trees, April 2013.

- MDA Glossary, VER. 4.0, https://mko.mda.mil/sites/training/SiteCollectionDocuments/MDA%20Glossary.pdf.

- CORS RCS File Discussion, 13 Mar 2013, Slide #2.

Environments - Definition List (DRAFT) E Environments

The aggregate of all natural, operational, or other conditions that affect the operation of equipment of components.

None.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- McGraw-Hill Dictionary of Scientific and Technical Terms, 5th Edition, Sybil Parker editor, McGraw-Hill, New York, NY, 1994, p. 686.

E 1 Earth Reference

Characteristics associated with the body of the earth and long range, high altitude flights or orbits above it.

None.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 14 of 83Content Updated: 2 Jul 2013

Additional Details Definition Reference(s)

E 1.1 Date and Time of Day

A suite of properties associated with marking the date and the time of day, i.e., epoch (for simulation time), earth rotation, earth shape or geoid, coordinates frame, and conversions between coordinate frames.

Epoch: A particular instant for which certain data are valid.

Earth Rotation: Angular motion about the earth's axis, where the axis is a straight line between the North and South poles. One revolution is completed every 23 hours, 56 minutes, and 04.09053 seconds. This duration is called the sidereal period because it designates the period of rotation relative to the stars. The rotation of the earth and its angular inclination with respect to the sun drive the diurnal and seasonal variations that affect the properties of its surface and atmosphere.

Earth Shape / Geoid: The figure of the earth considered as a sea-level surface extended continuously over the earth's entire surface. The Earth Shape is that of an ellipsoid, where the poles are squished and a bulge exists at the equator, instead of a true sphere. In fact, the equatorial bulge is measured at 26.5 miles (42.72 km). This distortion is caused by the centrifugal force induced by the earth’s rotation. The force is greatest at the equator because the equatorial surface lies the furthest from the axis of rotation, so it causes the equator to have a larger circumference and diameter. In order to study the earth, an ellipsoid is used as a mathematical model of its surface to measure distances without having to account for elevation changes and landforms. The Geoid (the shape that the surface of the oceans would take under the influence of earth's gravity alone in the absence of other influences such as winds and tides) is then employed to account for surface realities by constructing a global mean sea level that accounts for elevation changes.

Coordinate Frame and Conversions: The coordinate reference system for a computation and/or simulation of a complete or given part of a threat/target/interceptor flight and its associated phenomena, and the translation of coordinate points between different coordinate systems. For example, the launch and boost phases of a long missile flight may be referenced to an earth-centered, earth-fixed (ECEF) coordinate frame that rotates with the surface of the earth. However, when approaching near-orbital altitudes, it may be more convenient to convert to an earth-centered, inertial (ECI) coordinate frame that does not rotate with the earth. Cartesian coordinate systems are often used for microscale and mesoscale atmospheric calculations where the curvature of the earth can be neglected, while spherical coordinates are generally used for global computations where the curvature cannot be neglected. A celestial/inertial frame that is fixed with respect to space is used for orbit analysis, astronomy applications, and inertial motion. However, an earth-fixed frame is used for applications in geolocation and apparent satellite motion. For spacecraft, a spacecraft-fixed reference frame is applied to determine the vehicle's position and orientation. In addition, for spacecraft observing the earth, a location-horizontal frame is employed that is fixed to the vehicle and which uses nadir as the z-axis reference.

- http://geography.about.com/od/physicalgeography/a/geodesyearthsize.htm

- http://en.wikipedia.org/wiki/Geoid

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- Ask An Astrophysicist, "How fast The Earth Rotates" http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970401c.html

- MDA/ESP Core Truth Models, Environments Lead, Dr. Gregory Stargell, May 2013.

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Additional Details Definition Reference(s)

- MDA/ESP Core Truth Models, Environments, Kathryn Weik, May 2013.

- McGraw-Hill Dictionary of Scientific and Technical Terms, 5th Edition, Sybil Parker editor, McGraw-Hill, New York, NY, 1994, pp. 691, 634, 845.

- Fundamentals of Atmospheric Modeling, Second Edition, Mark Jacobson, Cambridge University Press, Cambridge, UK, 2005, p. 82.

- Space Mission Analysis and Design, 3rd Edition, J. Wertz and W. Larson, Space Technology Library, 1999, pp. 95-96.

E 1.2 Gravity

The acceleration imparted to a body by the attraction of the earth and which draws that body towards the center of the earth.

Gravity, or gravitational acceleration, is nearly constant near the earth's surface although it varies slightly with latitude since the earth is lightly ellipsoidal in shape.

However, gravitational acceleration definitely decreases with increased altitude. It should be noted that the gravitational force experienced on the surface is a combination of the force due to gravitational acceleration with the centrifugal force created by the rotation of the earth. It should also be observed that gravity varies slightly with the local terrain of the earth; a property that is accounted for with the geoid - a global mean sea level based on changes in elevation.

- MDA/EEV, Core Truth Models Support, Al Garber, July 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- Fundamentals of Atmospheric Modeling, Second Edition, Mark Jacobson, Cambridge University Press, Cambridge, UK, 2005, p. 95.

- MDA/ESP Core Truth Models, Environments Lead, Dr. Gregory Stargell, May 2013.

- MDA/ESP Core Truth Models, Environments, Kathryn Weik, May 2013.

- McGraw-Hill Dictionary of Scientific and Technical Terms, 5th Edition, Sybil Parker editor, McGraw-Hill, New York, NY, 1994, pp. 871-872.

- Physics for Students of Science and Engineering, Combined Edition, David Halliday and Robert Resnick, John Wiley & Sons, New York, NY, 1962, pp. 40, 328-329.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 16 of 83Content Updated: 2 Jul 2013

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E 1.3 Terrain

The ground or a tract of ground, especially with regard to its natural or topographical features.

Terrain is described by the elevation, slope, and orientation of surface features on the earth. It affects the flow and distribution of surface water, and over large areas it affects weather and climate patterns. Terrain can also affect a sensor's line-of-sight and communication transmissions.

In support of military applications, the National Imagery and Mapping Agency (NIMA) has developed standard digital datasets (Digital Terrain Elevation Data (DTED) which is a uniform matrix of terrain elevation values that provides basic quantitative data for systems and applications requiring terrain elevation, slope, and/or surface roughness information. This data is provided at three levels of spatial resolution.

. DTED Level 0 data (DTED0) has a resolution of 30 arc seconds (nominally one kilometer) which enables a gross representation of the Earth's surface for general modeling and assessment activities.

. DTED Level 1 data (DTED1) has a resolution of 3 arc seconds (approximately 100 meters). It constitutes the basic medium resolution elevation data source for all military activities and systems that require landform, slope, elevation, and/or gross terrain roughness in a digital format.

. DTED Level 2 data (DTED2) has a resolution of 1 arc second (roughly of 30 meters). It comprises the basic high resolution elevation data source for all military activities and systems that require landform, slope, elevation, and/or terrain roughness in a digital format. DTED2 is composed of a uniform gridded matrix of terrain elevation values. However, measurements at such a high resolution are extremely sparse.

- http://www.fas.org/irp/program/core/dted.htm

- MDA/EEV, Core Truth Models Support, Al Garber, July 2013.

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- Webster’s New World Dictionary of the American Language, Second College Edition, David B. Guralnik editor-in-chief, William Collins + World Publishing Company, Cleveland, OH, 1974, p. 1468.

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E 1.4 Albedo

The fraction of the total light incident on a reflecting surface, especially a celestial body, which is reflected back in all directions.

Albedo is the reflectivity of a surface, and it is wavelength-dependent. The albedo of the earth and atmosphere together, known as the planetary albedo, is about 30% when averaged over the visible spectrum for several surface types.

- Fundamentals of Atmospheric Modeling, Second Edition, Mark Jacobson, Cambridge University Press, Cambridge, UK, 2005, p. 283.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- MDA/ESP Core Truth Models, Environments, Kathryn Weik, May 2013.

- McGraw-Hill Dictionary of Scientific and Technical Terms, 5th Edition, Sybil Parker editor, McGraw-Hill, New York, NY, 1994, p. 59.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 18 of 83Content Updated: 2 Jul 2013

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E 1.5 Sea State

The numerical or written description of ocean-surface roughness.

Sea state is the general condition of the free surface on a large body of water with respect to wind waves and swell at a certain location and time. It is characterized by wave height, period, and power spectrum. It's numerical description is often reported using the World Meteorological Organization sea state code given below.

Sea State Code Wave Height (meters) Characteristics 0 0 Calm (glassy) 1 0 to 0.1 Calm (rippled) 2 0.1 to 0.5 Smooth (wavelets) 3 0.5 to 1.25 Slight 4 1.25 to 2.5 Moderate 5 2.5 to 4 Rough 6 4 to 6 Very rough 7 6 to 9 High 8 9 to 14 Very high 9 Over 14 Phenomenal

It should be noted that for BMDS operations the sea state is categorized using codes 1 to 5 listed above.

- http://en.wikipedia.org/wiki/Sea_state

- MDA/EEV, Core Truth Models Support, Al Garber, July 2013.

- MDA/ESP Core Truth Models, Phenomenology Lead, Carol Barclay, July 2013.

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- McGraw-Hill Dictionary of Scientific and Technical Terms, 5th Edition, Sybil Parker editor, McGraw-Hill, New York, NY, 1994, p. 1775.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 19 of 83Content Updated: 2 Jul 2013

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E 1.6 Earthshine

Upwelling spectral and in-band EO/IR radiation (both thermal earth emission and albedo-reflected irradiance) that illuminates earth-facing surfaces of threat/target/interceptor vehicles and vehicle components of interest.

Earthshine can be observed in the visible spectrum when reflected sunlight illuminates the night side of the moon. This results in the moon's night side being bathed in a soft, faint light. It is most observable shortly before and after a new moon (during the waxing or waning crescent phase) when the night side of the moon appears to glow faintly and the entire orb of the Moon is dimly visible.

- http://en.wikipedia.org/wiki/Earthshine#Earthshine.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- The Infrared Handbook, Revised Edition, William L. Wolfe and George J. Zissis editors, The Infrared Information Analysis (IRIA) Center, Environmental Research Institute of Michigan, 1989, pp. 3-3, 3-43 - 3-56, 3-84 - 3-142, 15-47 - 15-48, 15-54 - 15-57.

- McGraw-Hill Dictionary of Scientific and Technical Terms, 5th Edition, Sybil Parker editor, McGraw-Hill, New York, NY, 1994, p. 634.

E 1.7 Geomagnetic Field

The earth's magnetic field.

The earth's magnetic field, also known as the geomagnetic field, extends from the inner core of the earth to the solar wind, a stream of energetic particles emanating from the sun. Its magnitude at the earth's surface ranges from 25 to 65 μT (0.25 to 0.65 G), and it is approximately the field of a magnetic dipole tilted at an angle of 11 degrees with respect to the rotational axis. The geomagnetic field changes over time because it is generated by the motion of molten iron alloys in the earth's outer core.

- http://en.wikipedia.org/wiki/Earth%27s_magnetic_field

- MDA/DEA BMDS Capability Assessment, Models and Simulation, Steve Taylor, April 2013.

- MDA/ESP Core Truth Models, Phenomenology Deputy, Dr. Ed Vaughn, May 2013.

- McGraw-Hill Dictionary of Scientific and Technical Terms, 5th Edition, Sybil Parker editor, McGraw-Hill, New York, NY, 1994, p. 845.

"Distribution authorized to the Department of Defense and U.S. DOD contractors only; Administrative or Operational Use; 2 July 2013. Other requests shall be referred to MDA/ESP, Core Truth Models Lead. Page 20 of 83Content Updated: 2 Jul 2013

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E 2 Atmosphere

The gaseous envelope surrounding the earth.

The atmosphere contains a few highly concentrated gases (such as nitrogen, oxygen, and argon) and many trace gases, among them water vapor, carbon dioxide, methane, and ozone. All such gases are constituents of air. Important characteristics of air are its pressure, density, and temperature. These parameters vary with altitude, latitude, longitude, and season; they are related to earth other by the equation of state.

The earth's atmosphere is divided into five layers, with the thickest being near the surface and each higher layer thinning out with altitude until the last one eventually merges with space. These distinct layers are identified based on: thermal characteristics (temperature changes), chemical composition, movement, and density. Each of the layers is bounded by a "pauses" where the maximum changes in thermal characteristics, chemical composition, movement, and density occur.

The five layers of the atmosphere are listed below.

Troposphere: (0-6 km [4 miles] at the poles, 0-20 km [12 miles] at the equator) The troposphere is mostly heated by transfer of energy from the surface, so on average the lowest part of the troposphere is warmest with the temperature decreasing as altitude increases. This property promotes vertical mixing; hence the origin of its name in the Greek word trope, meaning turn or overturn. The troposphere contains roughly 80% of the mass of the atmosphere, and weather occurs in this layer. The transition boundary between the troposphere and the next layer, the stratosphere, is termed the tropopause. Together the tropopause and troposphere are known as the lower atmosphere.

Stratosphere: (6 - 20 [4 - 12 miles] to about 50 km [31 miles]) In the stratosphere temperature increases with altitude due to increased absorption of ultraviolet radiation by oxygen molecules, leading to the formation of ozone layer. While the temperature may be −60 °C (−76 °F; 210 K) at the tropopause, the top of the stratosphere is much warmer with a maximum value around -15 °C (5 °F). This temperature inversion restricts the vertical movement of air so that no convection, or mixing, occurs. Jet aircraft fly in the stratosphere because it is very stable. The transition boundary between the stratosphere and the next layer, the mesosphere, is the stratopause, which is typically located from 50 to 55 km (31 to 34 miles) and in which the pressure is 1/1000 that of the sea level value. The regions of the stratosphere and the mesosphere above it, along with the stratopause and mesopause, are termed the middle atmosphere.

Mesosphere: (about 50 km [31 miles] to 85 km [53 miles]) The gases of the mesosphere, including oxygen molecules, continue to become thinner with altitude. As a consequence, the effect of the warming by ultraviolet radiation decreases, leading to a corresponding decrease in temperature with altitude. On average, temperature decreases from about -15°C (5°F) to as low as - 120°C (-184°F) at the mesopause. At such temperatures water vapor is frozen, forming ice clouds (or Noctilucent clouds). In addition a type of lightning known as sprites or ELVES forms many miles above thunderclouds in the troposphere. Even with such a low density, though, the mesosphere is still sufficiently dense to slow down meteorites hurtling into the atmosphere, where they burn up, leaving fiery trails in the night sky. The boundary between the mesosphere and the exosphere above it is identified as the mesopause.

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Thermosphere: (85 km [53 miles] to 690 km (430 miles], although the height varies with solar activity) The thermosphere is characterized by increasing temperature with altitude due to the absorption of high energy ultraviolet and x-ray radiation from the sun.

Hence, the temperature in this layer is very sensitive to solar activity, and can vary from 500°C (880°F) to as high as 2,000°C (3,600°F) near the top of this layer.

However, despite the high temperature, the molecules and atoms in the thermosphere are so far apart that temperature in the usual sense is not well defined. In fact, the air is so rarefied that an individual molecule travels an average of 1 kilometer before colliding with another one.