SEG-D_8015 | 2½ bytes binary exponent data recording method

SEG-D 8015 is a C library. SEG-D 8015 has no bugs, it has no vulnerabilities and it has low support. You can download it from GitLab.

S = sign bit — Binary one means negative number. C = binary exponents — This is a 4 bit positive binary exponent of 2 written as 2CCCC where CCCC can assume values of 0-15. The four exponents are in channel number order for the four channels starting with channel one in bits 0-3 of Byte 1. Q-1-15 = fraction — This is a 15 bit ones' complement binary fraction. The radix point is to the left of the most significant bit (Q-1) with the MSB being defined as 2-1. The sign and fraction can assume values from 1 - 2-15 to -1 + 2-15. Note that bit 7 of the second byte of each sample must be zero in order to guarantee the uniqueness of the start of scan. Negative zero is invalid and must be convened to positive zero. Input signal = S.QQQQ,QQQQ,QQQQ,QQQ * 2CCCC * 2MP millivolts where 2MP is the value required to descale the data word to the recording system input level. MP is defined in Byte 8 of each of the corresponding channel set descriptors in the scan type header. Note that in utilizing this data recording method, the number of data channels per channel set must be exactly divisible by 4 in order to preserve the data grouping of this method. Source: Barry, K. M., Cavers, D. A. and Kneale, C. W., 1975, Report on recommended standards for digital tape formats: Geophysics, 40, no. 02, 344-352.