GC3GCXD Highest Sun (Unknown Cache) in Gauteng, South Africa created by Tartan

GC3GCXD ▼

A cache by Tartan_Terror Message this owner

Hidden : 8/29/2012

Difficulty:

Terrain:

Size: Size: regular (regular)

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Geocache Description:

A 2 litre rectangular hidden beneath a clearly marked boulder somewhere in Pretoria. Calculations required but all relevant data is included in listing. Solving methodology may demand additional research. Not suitable for low ground-clearance vehicles.

SIZE DOES COUNT

On 09 April 2012 we set out to hide a well stocked cache. Our GPS lost signal so we couldn't record the GZ coordinates in the traditional manner. We however improvised and used the tools at our disposal.

We held a 3.0 metre staff vertically on the ground and marked the tip of the shadow that it cast. Patiently we waited and watched the shadow move and change in length as the warm sun traversed the sky above. With utmost precision we recorded the time that the shadow was shortest; 12:08:29.536 on my Swiss manufactured wristwatch. The length of the shadow was also precisely measured as 2.000169m at the corresponding time.

Assume that the ground is level (0 gradient), ignore "refraction error" and work accurately to 6 decimal places during your calculations. All the data is on the listing, but you may have to research some background methodology. It's easier than what it seems, and 150m within GZ will turn Geochecker Green. In recognition of achievement, a prize awaits the FTF.

Supporting Data:
Extract from Nautical Almanac;
Arc to Time Conversion;