Syntax_Lm
Specify the Minimum Shallow Water BOA Radiance

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Lm
threshold on normalized bottom contrast Ls-Lsw

-Lm0001.0/000.5/004.p/0255
  • For a solution by band j,
    • any pixel which exhibits normalized bottom contrast Lr=(Ls-Lsw)
    • less than threshold Lm in band j
    • is considered too faint for modeling: it is declared optically deep
  • All Lm values must be >0 
  • May be specified in real number like 2.3
Lm=255
Lm can be specified to 255 
to disable totally any particular band solution
  • SIG: this is not compatible with the SIG trick though, in the -Z argument
  • SIG: for SIG to operate as desired, please make Lm<=10 for bands bm[1] to FirstSIG
  • FirstSIG: see Syntax_Z
p (optional)
For progressive dynamic setting of Lm: 
darker pixel are assigned a higher Lm value
  • this combats electronic noise or faint turbidity
  • progressive Lm is no less than original Lm/4, but increases as Lr[cKMin] decreases 
  • for example, see its effect in progressive_Lm, with -Lm0001.0/004.p/008.p/00005      
For a Landsat 8 OLIP image:
-M/@000001/@000002/00003/00004/@0005/00006/00007
-Lm/00001.0/000001.0/001.0/0001.0/0250.0/250.0/250.0
Thie result is:
  • the SWIR, NIR and Red solutions are disabled
  • the PAN and Green solutions are enabled
    • they shall be tested int that order
    • if the PAN solution is refused, then the Green solution shall be tested
    • if none is accepted, the result is: deep water
 


 

   

 



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