Surveyors Local Coordinate System (lcs) Northing Easting
How does one convert the lcs grid northing and easting to lat/long or state plane coordinates (spc). From time to time, a survey will show a 10,000 decimal , 1000 decimal, or 5000 decimal point northing and easting. Attached a plan here to show the points.
I work in the GIS mapping field, New Jersey, USA. Without a projected coordinate, I am left with only geo-referencing this map (based on objects can match to between survey and orthoimagery) to where I "think" it is located. Problem is that "thought" may not be "exactly" pinpoint to where the point of beginning is or bearing.
Please let me know if there is a formula to get the northing/easting converted to latitude/longitude or state plane.
Unless the surveyor provided conversion information (e.g., metadata in a note) there is no way to get an absolute location from the drawing. It would require the matching of features as you mention, or sending someone back with a GNSS receiver.
This kind of coordinate system is usually used when the surveyor feel that locating things relative to each other on the drawing is sufficient for the intended uses, did not make the measurements by GNSS, and there is no legal requirement for finding the location relative to a larger coordinate system.
The coordinates are on an assumed local datum. The surveyor chose a point to call 5000, 5000 (or 10000,10000 - or whatever struck his fancy) and ran with it. It is probable that the surveyor himself made no attempt to tie this survey to any outside coordinate system. A majority of local boundary surveys are done this way, especially were GPS is not the primary tool used.
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