Posunutí bodu o vzdálenost a směr

Question

<\/HEAD>Mám sérii bodů podél transektu, které je potřeba promítnout na různé vzdálenosti a směry od místa, kde byl bod zaznamenán, přičemž každý bod je jiný.<\/P> <\/P> Reálný příklad je při provádění průzkumů jelenů pro distance sampling, kdy se projíždí transekt a jakmile je pozorován jelen nebo skupina jelenů, zaznamená se waypoint, použije se laserový dálkoměr k měření vzdálenosti a změří se azimut pro získání přesné polohy. Jak lze tyto body posunout tak, aby ukazovaly polohu zvířete, aniž by bylo nutné vytvářet nové body, pokud je to možné?<\/P> <\/P> Prosím, žádné odpovědi ve formě kódu.<\/P><\/BODY><\/HTML>

ChadKopplin · Answer

In your GPS unit are you should be able to perform an offset of your waypoint.  Also, I did find this tool, maybe it could help, because if you can use a distance tool to create this line then you could convert the line to points and be left with your survey points.

ArcGIS Desktop Help 9.2 - Creating lines with the Offset Line window

DarrenWiens2 · Answer

There are a few mistakes in the script above, which will make it tricky (impossible) for a beginning to figure out. Particularly, needs to be "math.radians()", and typo in newFc vs newFC, all of which is compounded by not using the 'with' statement, so sCursor never gets deleted and causes yet more problems. I guess the point is, sometimes the out-of-the-box tools are worth it.

>>> import arcpy # import arcpy
... import math # import math
... fc = r'C:\junk\start_points.shp' # change to your existing input feature class
... new_fc = r'C:\junk
ew_points.shp' # change to your existing output feature class
... fields = ['POINT_X', 'POINT_Y', 'DISTANCE','BEARING'] # existing fields in input
... outFields = ['SHAPE@','x', 'y', 'distance','bearing'] # existing fields in output
... iCursor = arcpy.da.InsertCursor(new_fc,outFields ) # insert cursor
... with arcpy.da.SearchCursor(fc, fields) as sCursor: # search cursor
...     for row in sCursor: # loop through rows in search cursor
...         inputX = row[0] # 1st field in search cursor
...         inputY = row[1] # 2nd field in search cursor
...         distance = row[2] # 3rd field in search cursor
...         bearing = row[3] # 4th field in search cursor
...         bearing = math.radians(float(bearing)) # convert to radians
...         newX = inputX + distance * math.cos(bearing) # calc new X
...         newY = inputY + distance * math.sin(bearing) # calc new Y
...         point = arcpy.Point(newX,newY) # create new point
...         temp = [point,newX,newY,distance,bearing] # organize new attributes
...         iCursor.insertRow(temp) # write new row
... del iCursor # delete insert cursor

DarrenWiens2 · Answer

You can do this all using out-of-the-box ArcGIS tools:

1.) You need a table containing the observation point coordinates, bearing, and distance. If you need to add coordinates, use Add XY Coordinates tool.

2.) Run Bearing Distance to Line​

3.) Use Add Geometry Attributes to calculate the END_X and END_Y coordinates

4.) Make XY Event Layer using the END_X and END_Y coordinates

5.) Export the event layer to a feature class on disk