topic Re: Calculate the distance between two sequential points in wkid 4326 (WGS84 Geographic)? in ArcGIS Pro Questions

Calculate the distance between two sequential points in EPSG 4326 (WGS84 Geographic)?

AustinLewis — Fri, 11 Oct 2024 15:43:37 GMT

Hello,

I have a feature class of points representing positions that are ordered in such that they are chronological. The feature class is in WGS 84 geographic as it is part of a larger global dataset. I am trying to calculate the geodesic distance between each point and the previous point in the field calculator. My problem is all the tools I can find/think (ex. point.distanceTo()) of are only appropriate for a planar projected dataset. Does anyone now a way of doing this? Eventually, I will use this distance to calculate speed.

What I have now would would for a projected dataset. I will show that below.

# In the field calculator distance(!Shape!) # In the code block i=0 def distance(shape): global prev_point global i point = arcpy.PointGeometry(shape.getPart(0)) if i > 0: distance = point.distanceTo(prev_point) else: distance = 0 i+=1 prev_point = point return distance

Re: Calculate the distance between two sequential points in wkid 4326 (WGS84 Geographic)?

AustinLewis — Fri, 11 Oct 2024 15:29:04 GMT

I am also open to using Arcade or any other code solutions!

Re: Calculate the distance between two sequential points in EPSG 4326 (WGS84 Geographic)?

AustinLewis — Fri, 11 Oct 2024 19:05:46 GMT

I have found my issue. I needed specify the spatial reference frame when generating my point object. Additionally, I used "angleAndDistanceTo() instead of distanceTo(), as it has the option of using the 'GEODESIC' method. I believed I used something like the code below.

# In the field calculator distance(!Shape!) # In the code block i=0 def distance(shape): global prev_point global i spref = arcpy.SpatialReference(3426) point = arcpy.PointGeometry(shape.getPart(0),spref) if i > 0: angle, distance = point.angleAndDistanceTo(prev_point,'GEODESIC') else: distance = 0 i+=1 prev_point = point return distance