Specifications include, but are not limited to: Design and conduct high resolution helicopter airborne electromagnetic (EM) survey capable of delineating the Buried Valley Aquifers for hydrogeological features in eastern & central North Dakota using a Time Domain system specifically designed for groundwater systems. Study area (see Appendix B) to include a minimum of 1000 kilometers of survey lines. With a line spacing of 500 meters, and with a tie line spacing of 5000 meters. The airborne EM Time domain system must be capable of resolving lithological variations near-surface (~20 meters) and to depths upwards of 300 m below land surface throughout the project area producing both EM and Magnetic data. The geophysical service provider must use a helicopter based system with the following EM capabilities: The airborne Time Domain EM system shall use a transmitter with a square-wave waveform. The system’s transmitter coil shall be capable of at least 150,000 NIA peak dipole moment. Once field data collection is completed, the service provider must apply advance inversion techniques to process the collected 3D Time Domain data at an expectable vertical data density.
