## Subject: Brief Survey Plan

Prelim: Identify location of 4 lines so that at least one crosses the runway (civil engineering investigation). If two cross the runway, all the better; but this double-crossing of the runway may not be practical.

#1 Start laying out 3-km line; 2-3 people. Use trimble unit and proposed future satellite path to determine single start point and then the direction of this main line. One person goes out 100 meters and puts in the first "100 meter" stake (we'll paint them a different color than 5m stakes) along GPS-located line. Then, the next 100m stake can be placed using walkie-talkies and visual sighting--keeping the stakes lines up visually is accurate to a fraction of a degree, surprisingly. The GPS-holder follows approximately 3 stakes behind the "point man" and records the locations of the 100m stakes while sighting the subsequent stakes for the "point man." This should proceed quickly; probably about half as fast as one person could simply walk 3km. Maybe an hour for this 3km line.
While these two get the 100m stakes planted, a second pair of workers follow behind and use 100m measuring tape to mark off the 5m intervals between the 100m stakes. More than likely, however, they'll simply keep the tape in position for the EM-31 group to simply follow the tape, stop every 5m, and take their EM-31 and snow depth readings. If necessary for the survey, they can put in stakes at, say, 20m intervals, if that is deemed helpful.
Once the main 3-km line is laid out with 100m stakes, this group of 2-3 will then lay out the 1-km cross lines. Again, lines of sight and using physical right angle edges in coujunction with meter sticks will keep the accuracy of this to a fraction of a degree. Or, we could fashion a quick, larger carpenter's "right angle" up there and use that.
Finally, this survey group goes after the 100m x 100m grid at the center of the whole survey. This would be the best place for using the survey stakes in order to capture the "short wavelength" variations in ice thickness.

#2 EM-31 groups: They'll get started as soon as the first group gets a few of the 100m stakes planted. One EM-31 has a data logger, the other doesn't. The group with the logging Em-31 will need one person to drag the EM-31 and push the button to record the data, and one person to use a simple meter stick to push into the snow are record the snow depths in a field notebook. The group with the non-logging EM-31 could do with the same two people with the EM-31 dragger simply calling out the EM-31 readings for the other person. This proceeds quickly once a rhythm is established. Taking a reading and moving to the next location should take approx. 1 minute or so. Thus, at least think of this as one hour = 40+ readings (conservative estimate) = 200 m of data for each unit.
 Note A: The two EM-31 units will interfere with each other if they're "close by" each other in some sense. I don't know what "close by" means, but I can ask around and find out. It's quite a feat to have 2 EM-31 units working the same job. Note B: We need to calibrate both EM-31s at the same place up there. This will ensure data consistency. Note C: WE need to be sure to keep the two EM-31s pointed in the same direction throughout the entire survey. They are somewhat direction-senstive, although with the ice being isotropic this really should not be an issue. However, from a "control of variables" standpoint, this would be considered a requirement. This should also be the case when taking the readings on the 1km cross lines and the tightly-packed grid at the center of the array.

#3 "Drill teams" (what a great name): This must be done a distance from the EM-31 readings since the low frequency EM waves emitted by power generators and rotating electric motors will interfere with the EM-31 signals/readings. Thus, one the EM-31s are a few hundred meters away, this could start. This proceeds as fast as possible, with the data being fed to George Mason Univ. for analysis as well as being plotted on a computer at the pole.
 Note: This will be the slowest part. However, by the end of our time at the pole, some people will have finished with either their grid surveying and/or their EM-31 readings. Thus, any and all pairs of hands helping here would be used.