WSF
WsfMIT_ClutterStrength Class Reference

#include <WsfMIT_ClutterStrength.hpp>

Public Types

enum  TerrainType {
  cLOW_RELIEF_DESERT = 0 , cHIGH_RELIEF_DESERT = 1 , cLEVEL_DESERT = 2 , cLOW_RELIEF_FOREST = 3 ,
  cHIGH_RELIEF_FOREST = 4 , cLOW_RELIEF_AGRICULTURAL = 5 , cHIGH_RELIEF_AGRICULTURAL = 6 , cLEVEL_AGRICULTURAL = 7 ,
  cHIGH_RELIEF_SHRUBLAND = 8 , cLOW_RELIEF_SHRUBLAND = 9 , cHIGH_RELIEF_GRASSLAND = 10 , cLOW_RELIEF_GRASSLAND = 11 ,
  cWETLAND = 12 , cMOUNTAINOUS = 13 , cLONG_RANGE_MOUNTAINOUS = 14 , cHIGH_RELIEF_GENERAL_MIXED_RURAL = 15 ,
  cLOW_RELIEF_GENERAL_MIXED_RURAL = 16 , cGENERAL_URBAN = 17 , cTERRAIN_TYPE_SIZE = 18
}
enum  FrequencyBand {
  cVHF = 0 , cUHF = 1 , cL_BAND = 2 , cS_BAND = 3 ,
  cX_BAND = 4 , cFREQUENCY_SIZE = 5
}
enum  Polarization { cHH = 0 , cVV = 1 , cPOLARIZATION_SIZE = 2 }

Static Public Member Functions

static TerrainType GetTerrainType (WsfEnvironment::LandFormation aLandForm, WsfEnvironment::LandCover aLandCover)
static FrequencyBand GetFrequencyBand (double aFrequency)
static double GetLandClutterStrength (double aDepressionAngle, WsfEnvironment::LandFormation aLandFormation, WsfEnvironment::LandCover aLandCover, double aFrequency, WsfEM_Types::Polarization aPolarization)
 Computes the land clutter signal for various terrain types.
static double GetLandClutterStrength (double aDepressionAngle, TerrainType aTerrainType, FrequencyBand aFrequencyBand, Polarization aPolarization)
static double GetSeaClutterStrength (double aGrazingAngle, WsfEnvironment::SeaState aSeaState, double aFrequency, WsfEM_Types::Polarization aPolarization)
static double GetLandClutterStrengthLegacy (double aDepressionAngle, WsfEnvironment::LandFormation aLandFormation, WsfEnvironment::LandCover aLandCover, double aFrequency, WsfEM_Types::Polarization aPolarization)

Detailed Description

This class represents two sets of clutter data tables and the methods to perform table lookups, both of which derive from experiments performed by MIT / Lincoln Labs. The first of these come from the SALRAM clutter model, whose data derive from various open sources. The SALRAM data set contain the only sea clutter data available. The second source of data are for land clutter only and originate from The book Low Angle Radar Clutter, by J. Barrie Billingsley. As SALRAM land clutter data are now assumed to be superseded by the Billingsley data, lookups for these surface clutter values are performed with the method GetLandClutterStrengthLegacy.

Member Enumeration Documentation

◆ FrequencyBand

Define frequency bands supported in clutter table lookups (Frequencies are not interpolated in lookups.)

Enumerator
cVHF 
cUHF 
cL_BAND 
cS_BAND 
cX_BAND 
cFREQUENCY_SIZE 

◆ Polarization

Define polarizations supported in clutter table lookups. (either Horizontal-Horizontal or Vertical-Vertical).

Enumerator
cHH 
cVV 
cPOLARIZATION_SIZE 

◆ TerrainType

Define terrain types supported in clutter table lookups. These are not the same as enumerated in WsfEnvironment, but those landform/landcover designations are mapped to the corresponding type (which has its own table).

Enumerator
cLOW_RELIEF_DESERT 
cHIGH_RELIEF_DESERT 
cLEVEL_DESERT 
cLOW_RELIEF_FOREST 
cHIGH_RELIEF_FOREST 
cLOW_RELIEF_AGRICULTURAL 
cHIGH_RELIEF_AGRICULTURAL 
cLEVEL_AGRICULTURAL 
cHIGH_RELIEF_SHRUBLAND 
cLOW_RELIEF_SHRUBLAND 
cHIGH_RELIEF_GRASSLAND 
cLOW_RELIEF_GRASSLAND 
cWETLAND 
cMOUNTAINOUS 
cLONG_RANGE_MOUNTAINOUS 
cHIGH_RELIEF_GENERAL_MIXED_RURAL 
cLOW_RELIEF_GENERAL_MIXED_RURAL 
cGENERAL_URBAN 
cTERRAIN_TYPE_SIZE 

Member Function Documentation

◆ GetFrequencyBand()

WsfMIT_ClutterStrength::FrequencyBand WsfMIT_ClutterStrength::GetFrequencyBand ( double aFrequency)
static

Return the frequency band associated with the given frequency, for purposes of clutter lookup. Note: Frequencies above X-band still return X-band.

References cL_BAND, cS_BAND, cUHF, cVHF, and cX_BAND.

Referenced by GetLandClutterStrength().

◆ GetLandClutterStrength() [1/2]

double WsfMIT_ClutterStrength::GetLandClutterStrength ( double aDepressionAngleRad,
TerrainType aTerrainType,
FrequencyBand aFrequencyBand,
Polarization aPolarization )
static

Computes the land clutter signal for various terrain types.

Data based on The book "Low-Angle Radar Land Clutter", by J. Barrie Billingsley. This is the most extensive possible(?) representation of the MIT-LL data.

◆ GetLandClutterStrength() [2/2]

double WsfMIT_ClutterStrength::GetLandClutterStrength ( double aDepressionAngle,
WsfEnvironment::LandFormation aLandFormation,
WsfEnvironment::LandCover aLandCover,
double aFrequency,
WsfEM_Types::Polarization aPolarization )
static

Computes the land clutter signal for various terrain types.

References WsfEnvironment::cCALM_RIPPLED, WsfEnvironment::cWATER, GetFrequencyBand(), GetLandClutterStrength(), GetSeaClutterStrength(), and GetTerrainType().

Referenced by GetLandClutterStrength().

◆ GetLandClutterStrengthLegacy()

double WsfMIT_ClutterStrength::GetLandClutterStrengthLegacy ( double aDepressionAngleRad,
WsfEnvironment::LandFormation aLandFormation,
WsfEnvironment::LandCover aLandCover,
double aFrequency,
WsfEM_Types::Polarization aPolarization )
static

Computes the land clutter signal for various terrain types.

Data based on MIT Lincoln Lab's report on radar propagation at low altitude and tabulated radar ground clutter, and from Nathanson page 272. Data voids filled by J.A. Hueseman, E245 MDAC-STL. Radar ground clutter data as a function of depression angle and frequency was input by Ray Perry in Nov of 1986.

References WsfEnvironment::cCALM_RIPPLED, WsfEnvironment::cWATER, GetSeaClutterStrength(), and rad2deg.

◆ GetSeaClutterStrength()

double WsfMIT_ClutterStrength::GetSeaClutterStrength ( double aPsi,
WsfEnvironment::SeaState aSeaState,
double aFrequency,
WsfEM_Types::Polarization aPolarization )
static

Computes sea clutter backscatter coefficient.

The coefficient is computed as a function of radar frequency (FMhz) and radar beam grazing angle (psi) for several sea environments and radar polarizations -sigc

Basic sea clutter routine taken from NISC P001/ADRAD Model. Original data from Nathanson pgs 231-239. Data voids filled by E.M. Schultz, E245 MDAC-STL

References WsfEM_Types::cPOL_VERTICAL.

Referenced by GetLandClutterStrength(), and GetLandClutterStrengthLegacy().

◆ GetTerrainType()

WsfMIT_ClutterStrength::TerrainType WsfMIT_ClutterStrength::GetTerrainType ( WsfEnvironment::LandFormation aLandForm,
WsfEnvironment::LandCover aLandCover )
static

Given a land form / land cover pair, as defined in WsfEnvironment.hpp, return the corresponding terrain type (each terrain type has its own clutter strength table.

References cLOW_RELIEF_GENERAL_MIXED_RURAL, WsfEnvironment::cNUM_LAND_COVERS, and WsfEnvironment::cNUM_LAND_FORMS.

Referenced by GetLandClutterStrength().


The documentation for this class was generated from the following files:
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