topic Re: Updating well locations and suddenly lat/longs not displaying correctly? in Coordinate Reference Systems Questions

Updating well locations and suddenly lat/longs not displaying correctly?

ElizabethDever1 — Wed, 10 Jan 2018 16:09:50 GMT

I am updating a file to show the locations of proposed marcellus wells surrounding our municipality. Every time now that I put new lat/longs in they are showing up completely in the wrong places. I have checked the locations on google earth etc and in our records to make sure that the coordinates are right but have had no such luck in getting them to project. The raster layer has a dataum of NAD 83 (ft) and a spatial reference of state plane ft 83. The layer that is not projecting right is showing that the projected coordinate system is in state plane ft 83 and the geographic coordinate system is NAD 83 ft. Would someone be able to help me in fixing this?

Thanks

Re: Updating well locations and suddenly lat/longs not displaying correctly?

DanPatterson_Retired — Wed, 10 Jan 2018 18:07:03 GMT

some sample coordinates would help...

When you mention long/lats,

do you have them in the right order? (longitude is the X, latitude is the Y
Did you include a negative sign for longitude?
Did you ensure that the long/lats are given a defined coordinate system ( a GCS with a NAD83 datum)
Did you then project the long/lats to a suitable coordinate system with a NAD83 datum and planar units of feet? or are you just relying on projection-on-the-fly to match things up

Re: Updating well locations and suddenly lat/longs not displaying correctly?

ElizabethDever1 — Thu, 11 Jan 2018 13:30:21 GMT

Some sample coordinates: Long/Lat (40.579088, -79.668862) (40.42118,-79.55055) (40.421200,-79.550510)

I have included the negative in latitude as we are in NA (x,-Y) and the points have a defined coordinate system NAD83, they are also projecting into stateplane PA which is also NAD 83 and planar units of feet. Hope this helps some more, Thank you!

Re: Updating well locations and suddenly lat/longs not displaying correctly?

DanPatterson_Retired — Thu, 11 Jan 2018 13:38:05 GMT

Elizabeth...

NOTE!!! (latitude = 40.579088, longitude = -79.668862) ****** check that they are defined accordingly

The file should be defined as a GCS NAD83 (in the Geographic coordinate system section that is ....unprojected... not projected....

NAD83 is a datum... not a coordinate system.

Stateplane PA is a projected coordinate system with a NAD83 datum with units in feet.

Your coordinates are in decimal degrees (get X and Y corrected as per the first line) which are in a Geographic Coordinate System

Re: Updating well locations and suddenly lat/longs not displaying correctly?

JoeBorgione — Thu, 11 Jan 2018 13:50:07 GMT

Hmm.. LONGitude, Flatitude: X = Longitude, Y = Latitude, right? Positive X puts you east of the meridean, and negative Y puts you in the southern hemisphere. Or am I totally bass-ackwards? Not sure where PA stateplane comes into play here either. I'm in Utah roughly as far north as PA and a typical Long/Lat here is -111.5, 41.5.

What are you trying to display? XY events? A projected point feature class? An undefined-projection feature class?

Try this: open up an mxd with a feature class of your desired projection to set the data fram properties. Use the go to button (or what ever it is called) and add a lat/long, or long/lat pair as your show them here. Zoom to that point. Then add the same pair in reversed order.

eta moments later: Dan is on an eastern time zone and is more awake than I am, beating me to it!

Dan_Patterson‌