By

Bob Buecher

One Measurement – You Know The Answer

Two Measurements – Which Is Correct?

How Accurate Is A Radio Location?

Exact (I did it)

+/- 1% of the Depth

Sources of Error

•Operator Error

•Beacon Not Level

•Misshapen Tx Antenna

•Non-Perpendicular Rx Antenna

•Non-Homogeneous Rock

•Beacon Movement

•Survey Errors

•Radio Interference

Reduce and Identify ErrorsBy Repeated Locations

Downside:More Locations Takes More Time & CoordinationErrors reduced by Squareroot of number of Locations

We don’t need to know the absolute position of stationsin the cave, only the relative positions.

Average Error 2.5 ft. (1.0 ft.)1.5% (0.6%)

Depth 100 ft.Average Error 1.5 ft.

1.5%

Horizontal Position Should be Good to Within 1.5% of Depth or Better.

Estimates of position error can be made with two locations ‘close’ together.

Good Techniques can minimize operator errors and Equipment Bias.

A complete Survey is Not Necessary to Determine Position Uncertainty.

Lessons Learned

Cave Radio Locations are on the Cutting Edge of Quantum Physics

Like Sub-Atomic ParticlesThe Location Has A Probability Spread Over A Wide AreaWhen Measured Probability Field CollapsesInto …