Block IV: Environmental Model

RDOASP supports all the environmental models allowed for SAFARI as well as the ones described above in Section 4.1. The stepwize range-independent environment is specified by a standard OASP environment block for each sector, with the length of the sector added to the line containing the number of layers. The sector length is given in kilometers. The significance of the environmental parameters is as follows

NSEC:

Number of sectors, each of which should have a block with layer data in input file.

NL:

Number of layers, including the upper and lower half-spaces. These should Always be included, even in cases where they are vacuum.

SECL:

Length of sector in kilometers.

D:

Depth in m of upper boundary of layer or halfspace. The reference depth can be choosen arbitrarily, and D() is allowed to be negative. For layer no. 1, i.e. the upper half-space, this parameter is dummy.

CC:

Velocity of compressional waves in m/s. If specified to 0.0, the layer or half-space is vacuum.

CS:

Velocity of shear waves in m/s. If specified to 0.0, the layer or half-space is fluid. If CS()< 0, it is the compressional velocity at bottom of layer, which is treated as fluid with 1/c(z)² linear.

AC:

Attennuation of compressional waves in . If the layer is fluid, and AC() is specified to 0.0, then an imperical water attenuation is used (Skretting & Leroy).

AS:

Attenuation of shear waves in

RO:

Density in g/cm³.

RG:

RMS roughness of interface in m. RG(1) is dummy. If RG<0 it represents the negative of the RMS roughness, and the associated correlation length CL should follow. If RG>0 the correlation length is assumed to be infinite.

CL:

Roughness correlation length in m.