topic Re: X Y Data in Attribute Table Questions in Map Projections Questions

X Y Data in Attribute Table Questions

LGalyen — Wed, 20 Mar 2019 18:54:38 GMT

I have 40k points the attribute table has multiple x and y fields all have different numerics. None of them seem to match any coordinate system.

Can someone explain the format of these columns

Projected Coordinate System: NAD_1983_StatePlane_Arizona_Central_FIPS_0202_Feet_Intl

Projection: Transverse_Mercator

False_Easting: 700000.00000000

False_Northing: 0.00000000

Central_Meridian: -111.91666667

Scale_Factor: 0.99990000

Latitude_Of_Origin: 31.00000000

Linear Unit: Foot

thanks

Re: X Y Data in Attribute Table Questions

Egge-Jan_Pollé — Wed, 20 Mar 2019 19:09:24 GMT

Probably the quickest way to get an answer to your question would be to contact the provider of the attribute table. They will (or at least should) be able to explain the content of the different fields.

Egge-Jan

Re: X Y Data in Attribute Table Questions

DanPatterson_Retired — Wed, 20 Mar 2019 19:18:40 GMT

You truncated off the latitude and longitude coordinates, but your Xcoord and Y coord fields appear to be be lat and long

75400100 Is your longitude which for some reason should be

-75.400100 for the western hemisphere (positive for the eastern hemisphere)

similarly for the Ycoordinate.

You could just add two new fields and do the appropriate conversion in the field calculator, then you will actually have coordinates that you can map as a Geographic coordinate system perhaps a GCS WGS84 if the datum is assumed as such

Re: X Y Data in Attribute Table Questions

LGalyen — Wed, 20 Mar 2019 19:26:00 GMT

That is what I thought but the first event field was populated with -44.100 etc then some didn't have -'s the next set had no +/- then last set were truncated.... but appreciate the help thank you

Re: X Y Data in Attribute Table Questions

MelitaKennedy — Wed, 20 Mar 2019 23:39:34 GMT

Try mapping the points using the XADJ and YADJ fields and the given coordinate system: NAD_1983_StatePlane_Arizona_Central_FIPS_0202_Feet_Intl. The false easting (x value at center of zone) of the coordinate system is 700000. The XADJ field has values around 700k. I think the XCOORD and YCOORD fields have values in 100th of a foot. This is sometimes used in surveying or engineering.

I wouldn't trust the EVENT_X or EVENT_Y fields. The EVENT_Y field values are nonsensical.

Melita

Re: X Y Data in Attribute Table Questions

DanPatterson_Retired — Wed, 20 Mar 2019 23:44:57 GMT

1/100th of a foot? now I have heard of everything

Re: X Y Data in Attribute Table Questions

LGalyen — Tue, 26 Mar 2019 15:55:02 GMT

Melita thanks, nonsensical is a perfect word to describe those numbers!!! I spent several hours of mental work trying to understand them.