65
PATCH_NAME: Name of the setup;
SURVEY_LINE: Name of survey line;
Coil calibration response strings: The number of strings is determined by byte 9 (number of coil).
For each coil calibration string, the keyword of the string pair is the coil calibration file, the value
of the string pair is the frequency response in the pattern of “Freq1_RealRsp1_Imag_Rsp1_
Freq1_RealRsp1_Imag_Rsp1…. Freq2_RealRsp2_Imag_Rsp2”
Byte 6(Unsigned Integer):
Number of segment. The segment concept comes from 3D seismic
layout. It is normally 1 and maximum 2 without LTU in Geode EM3D.
Byte 7(Unsigned Integer):
Number of Boxes in the layout.
Byte 8(Unsigned Integer):
Number of channels in the layout.
2)
Field Layout Block
The field Layout Block consists of segment, box and channels sub-blocks;
Segment sub-block:
Use the number of segments in byte 6 of file descriptor mentioned above to determine how
many segment descriptor structures need to be read or written. The size of each segment
description is 49 bytes. It contains following 6 fields;
Byte0-15
: unused (it was assigned as the survey line the segment, but is disabled at this moment
(May of 2016).
Byte 16
(unsigned integer): Number of receiver boxes in the segment.
Byte 17-24
(
8 bytes IEEE Float, sign bit, 11-bit exponent, 52-bit mantissa
): planned telluric dipole
length in the segment. The actual E-channel dipole length can be changed in the program later.
Program uses the length to automatically setup the array layout. But a user can change the
dipole length of any channel if necessary.
Byte 25-32
(
8 bytes IEEE Float, sign bit, 11-bit exponent, 52-bit mantissa
):The azimuth of the
segment.
Byte 33-40
(
8 bytes IEEE Float, sign bit, 11-bit exponent, 52-bit mantissa
): Starting easting
coordinates of segment.
Byte 41-48
(
8 bytes IEEE Float, sign bit, 11-bit exponent, 52-bit mantissa
): Starting northing
coordinates of segment.
Box definition sub-block:
Uses the number of boxes for each segment (byte 16) of segment sub-block mentioned above to
determine how many box descriptors need to be read or written. The size of each box descriptor
structure is 31 bytes. It contains the following 10 fields;
