Input Files for OASI

 

Table 11: OASI input file structure, mandatory components: Environment, Array geometry and Sources.

Input parameter	Description	Units	Limits
Block I: TITLE
TITLE	Title of run	-	80 ch.
Block II: OPTIONS
A B C	Output and computational options	-	40 ch.
Block III: FREQUENCIES
FREQ1, FREQ2, NFREQ, COFF	FREQ1: Minimum frequency	Hz	>0
	FREQ2: Maximum frequency	Hz	>0
	NFREQ: Number of frequencies		>0
	COFF: Integration contour offset	dB/
Block IV: ENVIRONMENT
NL	Number of layers, incl. halfspaces	-
D,CC,CS,AC,AS,RO,RG,CL	D: Depth of interface.	m
.	CC: Compressional speed	m/s
.	CS: Shear speed	m/s
.	AC: Compressional attenuation	dB/
.	AS: Shear attenuation	dB/
	RO: Density	g/cm3
	RG: RMS of interface roughness	m
	CL: Correlation length of roughness	m	>0
Block V: RECEIVER ARRAY
NRCV	NRCV: Number of receivers in array	-	>0
Z,X,Y,ITYP,GAIN	Z: Receiver depth	m
.	X: x-offset of receiver	m
.	Y: y-offset of receiver	m
.	ITYP: Receiver type	-	>0
	GAIN: Receiver signal gain	dB
Block VI: NOISE SOURCES
SSLEV,WNLEV,DSLEV,NDNS	SSLEV: Surface noise source strength	dB
	WNLEV: White noise level	dB
	DSLEV: Deep source level	dB
	NDNS: Number of discrete sources

 

Table 12: OASI input file structure, optional components: Computational parameters.

Input parameter	Description	Units	Limits
Block VII: SEA SURFACE NOISE (SSLEV 0)
CMINS,CMAXS	Phase velocity interval, surface noise
	CMINS: Minimum phase velocity	m/s	>0
	CMAXS: Maximum phase velocity	m/s	>0
NWSC,NWSD,NWSE	Wavenumber sampling, surface noise
	NWSC: Samples in continuous spectrum
	NWSD: Samples in discrete spectrum
	NWSE: Samples in evanescent spectrum
Block VIII: DEEP NOISE SOURCES (DSLEV 0)
DPSD	DPSD: Depth of deep source sheet
CMIND,CMAXD	Phase velocity interval, deep sources
	CMIND: Minimum phase velocity	m/s	>0
	CMAXD: Maximum phase velocity	m/s	>0
NWDC,NWDD,NWDE	Wavenumber sampling, deep sources
	NWDC: Samples in continuous spectrum
	NWDD: Samples in discrete spectrum
	NWDE: Samples in evanescent spectrum
Block IX: DISCRETE SOURCES (NDNS > 0)
ZDN,XDN,YDN,DNLEV	ZDN: Depth of discrete source	m
:	XDN: x-offset of discrete source	km
:	YDN: y-offset of discrete source	km
	DNLEV: Source level of discrete source	dB
CMIN,CMAX	Phase velocity interval, discrete sources
	CMIN: Minimum phase velocity	m/s	>0
	CMAX: Maximum phase velocity	m/s	>0
NW,IC1,IC2	NW: Wavenumber sampling, discrete sources	-
	IC1: First sampling point	-
	IC2: Last sampling point	-	NW
Block X: SIGNAL REPLICAS (Option R)
ZSR,XSR,YSR,SRLEV	ZSR: Depth of replica source	m
	XSR: x-offset of replica source	km
	YSR: y-offset of replica source	km
	SRLEV: Source level of replicasource	dB
LY1,PA1,VMIN1,VMAX1,NV1	Replica parameter 1
LY2,PA2,VMIN2,VMAX2,NV2	Replica parameter 2
CMINR,CMAXR	Phase velocity interval, replicas
	CMINR: Minimum phase velocity	m/s	>0
	CMAXR: Maximum phase velocity	m/s	>0
NWR,ICR1,ICR2	NWR: Wavenumber sampling, replicas	-
	ICR1: First sampling point	-
	ICR2: Last sampling point	-	NWR

The input file for oasi is structured in 10 blocks, of which most are identical to the format for OASN. The first 6 blocks, shown in Table 11,contain data which must always be given, such as the frequency selection, the environment and receiver array. The last 4 blocks should only be included for certain options and parameter settings, as indicated in Table 12. The various blocks and the significance of the data is described in the following.