Frequently Asked Questions
Any frequently asked questions regarding RFP 2019-03 will be posted on this page.
Q: Which direction should the horizontal gradient magnetic data be collected in? Across the flight line or along the flight line? Just one direction or two directions?
A: Horizontal gradient is to be collected perpendicular or across the flight line. In-line horizontal gradient can be provided, but it is not being requested.
Q: The RFP states, “A noise envelope of 0.1 nanoteslas is required.” Can we offer to provide a magnetic sensor(s) with a noise envelope of 0.002 nT peak to peak?
A: Yes, a better noise envelope is welcomed. The noise envelope is in reference to the final compensated data and not technical specifications of the sensor.
Q: Am I correct in assuming that the 4 provincial parks (Nimpkish Lake, Lower Tsitka River, Schoen Lake, Woss Lake), contained within the intended survey area, are ‘no-fly’ zones? In other words, are we required to fly around them or are we able to fly through them but aren’t required to deliver data covering their extents?
A: The parks are considered to be areas where we do not want data collected. Flying through them or around them would be a decision that is left to the contractor assuming they have been granted any permissions that would be required to fly through them.
Q: The RFP refers to final Total Magnetic Intensity and Residual Magnetic Intensity grids. Is the difference simply the removal of the IGRF?
A: The RMI (residual magnetic intesity is the removal of the IGRF).
Q: Are tree tops and other flight obstacles considered “ground level”? What is the tolerance on height that Geoscience BC will accept?
A: Treetops and other flight obstacles are not considered ground level. However, the contractor and pilot(s) must conduct the survey safely and that will mean surveying at a safe height above or around obstacles.
Tree density can play a significant role in the ultimate height above ground level. A combination of dense forests and terrain could require aircraft to operate at 80 m above treetops. This decision is left up to the pilot. A combination of laser and radar altimeter and pilot experience may allow a survey to be conducted closer to the desired 80 m above ground level. However, the safety of survey crew is the deciding factor.
Q: What is the range of maneuvers (degrees of pitch, roll, and yaw) that are acceptable for the compensation test?
A: The ideal range of maneuvers that produces the best compensation of the survey data. It anticipated that contractors would desire excellent compensated survey data and this would be compromised if they chose to generate a “false” FOM test just to look good. It is not up to Geoscience BC to define the FOM parameters. Airborne geophysical contractors should be well aware of industry standards. Contractors are welcome to include pitch, roll and yaw information in their FOM summary statistics. Citing the reference below a FOM test could be defined as “+/- 10° rolls, +/- 5° pitches and +/- 5° yaws peak-to-peak along north, south, east and west headings over periods of 4 to 5 seconds.”
For further reference one could review: Geological Survey of Canada aeromagnetic surveys: design, quality assurance, and data dissemination, M. Coyle, R. Dumont, P. Keating, F. Kiss, and W. Miles, 2014. Open File 7660, 48 p. doi:10.4095/295088
Q: Can we use actual navigation results from previous surveys as guidance for what Geoscience BC will find acceptable in 2019?
A: Yes. Please feel free to use any publicly available data that will assist with your bid which can include available navigation results.
You can email any questions to RFP Coordinator Brady Clift: email@example.com