Input Files for OASSP

The input files for OASSP are virtually identical to the ones used for computing the mean field using OASP. A few of the options have different significance (s), and the option p is unique to OASSP. In addition, OASSP is unique in terms of allowing for computation of the reverberation from sound speed inhomogeneities in fluid layers. The spatial statistics of the volume inhomogeneities is controlled by the interface roughness parameters for such layers. The input files for OASSP are structured in 8 blocks, as outlined in Table15.

 

Table 15: Layout of OASP input files: Computational parameters.

Input parameter	Description	Units	Limits
BLOCK I: TITLE
TITLE	Title of run	-	80 ch.
BLOCK II: OPTIONS
A B C	Output options	-	40 ch.
BLOCK III: SOURCE FREQUENCY
FRC,COFF,IT,VS,VR	FRC: Center frequency of source	Hz	>0
	COFF: Integration contour offset	dB/	COFF
	IT: Source pulse type (only for option d)
	VS,VR: Sou./Rec. velocity (only for option d)	m/s
BLOCK IV: ENVIRONMENT
NL	Number of layers, incl. halfspaces	-	NL
D,CC,CS,AC,AS,RO,RG,CL	D: Depth of interface.	m	-
.	CC: Compressional speed	m/s	CC
.	CS: Shear speed	m/s	-
.	AC: Compressional attenuation	dB/	AC
.	AS: Shear attenuation	dB/	AS
	RO: Density	g/cm3	RO
	RG: RMS value of interface roughness	m	-
	CL: Correlation length of roughness	m	-
BLOCK V: SOURCES
SD,NS,DS,AN,IA,FD,DA	SD: Source depth (mean for array)	m	-
	NS: Number of sources in array	-	NS>0
	DS: Vertical source spacing	m	DS>0
	AN: Grazing angle of beam	deg	-
	IA: Array type	-	IA
	FD: Focal depth of beam	m	FDSD
	DA: Dip angle. (Source type 4).	deg	-
BLOCK VI: RECEIVER DEPTHS
RD1,RD2,NRD	RD1: Depth of first receiver	m	-
	RD2: Depth of last receiver	m	RD2>RD1
	NRD: Number of receiver depths	-	NR>0
BLOCK VII: WAVENUMBER SAMPLING
CMIN,CMAX	CMIN: Minimum phase velocity	m/s	CMIN>0
	CMAX: Maximum phase velocity	m/s	-
NW,IC1,IC2,IF	NW: Number of wavenumber samples	-	>0, -1 (auto)
	IC1: First sampling point	-	IC1
	IC2: Last sampling point	-	IC2NW
	IF: Freq. sample increment for kernels
BLOCK VIII: FREQUENCY AND RANGE SAMPLING
NT,FR1,FR2,DT,R1,DR,NR	NT: Number of time samples		NT=2M
	FR1: lower limit of frequency band	Hz
	FR2: upper limit of frequency band	Hz	FR1
	DT: Time sampling increment	s	> 0
	R1: First range	km
	DR: Range increment	km
	NR: Number of ranges		> 0