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NS Projections and Datums Mystery Cache

Hidden : 6/12/2021
Difficulty:
3 out of 5
Terrain:
2 out of 5

Size: Size:   micro (micro)

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Geocache Description:


CACHE IS NOT AT THE POSTED COORDINATES! 

To find the Final cache coordinates you must solve the puzzle. 

Understanding projections and datums is important when trying to compare historic maps with modern ones. In Nova Scotia a historic datum that is still in use for some applications is ATS77. ATS77 was used for postioning in Nova Scotia prior to the establishment of NAD83(Original) and currently (2021) Nova Scotia is using NAD83(CSRS)v6/v7. 

For simplicity of the puzzle we can assume that the WGS84 coordinates from the GPS and NAD83(Original) coordinates are equivalent.

 

For the puzzle follow the steps below:

Step 1: Determine which MTM zone the puzzle cache is located

Step 2: Coordinates for cache in ATS 77 MTM zone X are E 5566902.071 m N 4946601.582 m

Step 3: Visit the online tool to convert ATS77 MTM zone X coordinates to NAD83(Original) https://webapp.geod.nrcan.gc.ca/geod/tools-outils/ntv2.php

Step 4: Set the converter to "From: NAD27  To: NAD83(Original)"

            Set “UTM/MTM/Stereo”

            Select the correct zone using select zone” 

Step 5: Populate the Easting and Northing from Step 2 into the conversion tool

Step 6: Resulting coordinates in NAD83(Original) must be converted from DMS to DM

Additional Hints (Decrypt)

Fgrc 4: Jung cebivapr naq ZGZ mbar vf gur pnpur ybpngrq Fgrc 6: Hfr n pnyphyngbe sbe pbairefvba, bayvar gbbyf fbzrgvzrf ybfr cerpvfvba naq ebhaq gur inyhrf. Erzrzore 1' vf 60"

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M
-------------------------
N|O|P|Q|R|S|T|U|V|W|X|Y|Z

(letter above equals below, and vice versa)