3.3.1. Survey Index File¶
This file is input when forward modeling data. Using 4 columns, the observation file indexes the frequencies, transmitters and receivers used for each measurement. Each row defines a unique field measurement. The general format is as follows:
- Due to the way the forward problem is solved, it is imperative that the user sort the survey index file:
First by transmitter
Next by frequency
Then finally by receiver
tx_ind: The index corresponding to the desired transmitter within the transmitter file.
f_ind: The index corresponding to the desired frequency within the frequencies file.
rx_ind: The index corresponding to the desired receiver within the receiver file.
1: As of May 2018, a flag value of 1 is entered here. In future iterations of the code, this entry may be related to additional functionality.