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Public Land Survey Monument Report <br /> West 1/4-Corner of Section 3, T7N R1OE (City ID 710020) <br /> December 30,2016 <br /> To:Jeff Quamme <br /> City of Madison,WI Engineering Division <br /> Mapping Section <br /> This is to certify that on December 22, 2016 I found an offset drill hole(1/2-inch NW of center) in a brass <br /> cap monument under a square monument box, representing the West 1/4-Corner of Section 3, T7N R10E. <br /> The monument was intact and all 4 witness ties were intact per my previous Nov 20 2007 monument <br /> record. <br /> Below is a comparison of the coordinates and elevations from the 2007 monument record and my survey: <br /> Source Northing(US ft) Easting(US ft) Elevation(ft) <br /> 2007-11-20 491610.80 841914.97 894.95 <br /> 2016-12-22 491610.82 841915.06 895.13 <br /> Difference +0.02 +0.09 +0.18 <br /> 95% accuracy of my values is +/- 0.07 ft horizontal and +/- 0.04 ft vertical, based on a combined <br /> adjustment of GPS and total station observations. <br /> My horizontal coordinates are Dane County Coordinates, U.S. survey feet, NAD83(2007) datum, relative <br /> to the Emil Street GPS base station (MAON) at 43°02'12.78285"N, 89°24'34.27099"W (Easting <br /> 814396.30, Northing 469050.00 U.S. survey feet). The Wisconsin Coordinate Reference Systems <br /> (WISCRS) parameters were used to compute Easting, Northing coordinates. The horizontal differences in <br /> the table above are close to expected datum shifts between the 2007 survey (in NAD 83(1997) per old <br /> Sayle St base)and the current one. <br /> My 2016 elevation is in the NAVD 88(1991)datum(1991=original adjustment),determined from the same <br /> measurement adjustment as for the horizontal coordinates, from the Emil Street base station at ellipsoid <br /> height 815.84 ft (bottom of antenna mount), NAD 83(2011)(EPOCH 2010.00) datum, and the GEOIDI2 <br /> (=12A =12B here) geoid model, then subtracting 0.17 ft to convert from NAVD 88(2012) to NAVD <br /> 88(1991). <br /> My Nov 2007 elevation of 894.95 ft is for the same reset monument, but is a local perpetuation (based on <br /> measure-down from box rim) of the published elevation of the previous monument on the 2004 Sandsnes <br /> monument record. In contrast, the 2016 elevation is solved independently from the GPS base station. The <br /> difference of+0.18 ft is similar to a difference of+0.12 ft I observed from the GPS base in 2007 but did not <br /> use. I am reporting the two to assist others in a discrepancy they may find. <br /> Signed, <br /> 4 - <br /> Dan Rodman <br /> Professional Land Surveyor <br /> City of Madison Parks Division <br /> 210 Martin Luther King,Jr.Blvd, Suite 104 <br /> Madison,WI 53701 <br /> Office 608-266-6674 <br /> Cell 608-209-7012 <br /> �1 710 c XC,C, <br />