Surfer 6 Binary Grid File Format

Surfer 6 grid files .GRD use a layout similar to the Surfer 6 Text grid format. The only difference is in the identification string and that Surfer 6 grid files are binary. Data types used in Surfer 6 grid files include:

Type

Description

char

single byte

short

16 bit signed integer

float

32 bit single precision floating point value

double

64 bit double precision floating point value

The Surfer 6 format has the following layout:

Element

Type

Description

id

char

4 byte identification string ‘DSBB’ which identifies the file as aSurfer6binary grid file.

nx

short

number of grid lines along the X axis (columns)

ny

short

number of grid lines along the Y axis (rows)

xlo

double

minimum X value of the grid

xhi

double

maximum X value of the grid

ylo

double

minimum Y value of the grid

yhi

double

maximum Y value of the grid

zlo

double

minimum Z value of the grid. NoData nodes are not included in the minimum.

zhi

double

maximum Z value of the grid. NoData nodes are not included in the maximum. Note that if all nodes are assigned NoData, the zlo=zhi= 1.71041e38.

z11, z12, …

float

first row of the grid. Each row has a constant Y coordinate. The first row corresponds to ylo, and the last row corresponds to yhi. Within each row, the Z values are ordered from xlo to xhi. NoData values appear as 1.71041e38.

z21, z22, …

float

second row of the grid

z31, z32, …

float

third row of the grid

float

all other rows of the grid up to yhi

See Also

File Format Chart

Grid Files

Surfer 6 Grid Export Automation

Surfer 6 Grid Export Dialog

Surfer 6 Text Grid Format

Surfer 7 Grid Files