Sound speed profile format

The standard sound speed profile used in SIS has the file extension .asvp ( ASCII sound velocity profile). The file layout is as follows:

Header (the first line enclosed in brackets)

( SoundVelocity Version Id Time Lat Long Radii Valid_from Valid_to Src Hist No_val )

Note Notice the space character after the leading bracket and before the closing bracket.

SoundVelocity:

An identification of the file type (sound speed profile file).

Version:

The file format version number (usually 1.00).

Id:

A possible identifier

Time:

The time of creation for this file (YYYYMMDDhhmm).

Lat:

The latitude of the profile location (decimal degree).

Long:

The longitude of the profile generation (decimal degree).

Radii:

The radii around the lat/long position for which this profile is valid (m).

Valid from:

The time interval in the year from which this profile is valid (YYYYMMDDhhmm).

Valid to:

The time interval in the year to which this profile is valid (YYYYMMDDhhmm).

Src:

The source of the profile (e.g. probe name, database name, editors name etc.).

Hist:

The history of modifications on the profile (P=probe, E=edited, M=merged, N=new).

No val:

The number of values that are used in the profile.

Data

Depth:

The water depth (m).

SounVelocity:

The sound speed (m/s) at the corresponding depth.

An example:
( SoundVelocity 1.00 12 200605290813 22.3452678
66.4483298 4500 200605290813 200605301210 SVP-16 PE 8 )
0.1 1483.6
5.0 1484.2
7.0 1485.3
12.0 1488.1
20.0 1485.7
25.0 1484.0
40.0 1483.8
12000.0 1509.6

Data restrictions:

Legacy echosounders (i.e. EM 120, EM 300, EM 1002, EM 2000 and EM 3000,) can handle maximum 570 data entry points.

The new generation of echosounders (i.e. EM 122, EM 302, EM 710, ME 70 and EM 3002,) can handle maximum 1000 data entry points.

Note "Sound speed" is the correct technical term , but "Sound velocity" is used in the file extension (.asvp) and in the file format definition due to historical reasons.