My job requires me to enter point features into ArcGIS 10 which correlate to underground RFID markers that mark underground telecom infrastructure. Right now, the workflow requires someone to go out, find a marker, and then draw sketch with measurements to objects on the ground that are visible from an aerial photo to use as reference points. Then, I take measurements off those same reference points in ArcGIS to find the spot where I need to put the point feature. I use the normal measuring tool for this, which has a serious drawback. I've found no way to keep my measurement lines on the screen (or drop a temporary marker or something) when I switch to the edit feature tool to actually drop in the point. Since the points are often out in the middle of streets or fields, I can't just "eyeball" it. This process is too imprecise already.

The workaround I've come up with is using a sticky note and sticking it on my monitor with the corner pointing at the spot where the point should go before I switch tools. There has to be a better way. Any suggestions?

I'd also be interested to hear if there are workflows out there using GPS devices like the Trimble Geoexplorer 6000 series which people have found to be fast enough to justify the investment in the equipment. What we're doing now is labor intensive and error prone. Help me convince my boss to drop $5k on a sub-decimeter GPS!


  • Surprised the RFID markers are not tied to GPS coordinates - this hardware will do that - rfidc.com/docs/outdoor_gps_tracking.htm with GSM/GPRS triangulation when GPS coverage is not available - screen shots at the bottom is ArcMap and Google Earth real-time. – Mapperz Nov 11 '11 at 3:16

Why not create a new line feature class called "Point_Construction_Lines" then, instead of using the measure tools, use bearings and distance (eg. the COGO toolbar) to recreate the sketch in the line feature. Save your edits then enter the point.

If you only have one "measurement" line you can also use the "Point at end of line" construction tool.

That said, unless your people out in the field are using proper surveying techniques (ie an electronic theodolite etc. to get precise measurments) I think you would be much, much better off with a handheld GPS. It wouldn't even need to be an especially accurate one to improve on your current precision.

  • or in 10 the edit has draw point at the end of a line. You make the bearing measurements like normal with a line and when you double click (f2) the line goes away and you have a point there. – Brad Nesom Nov 11 '11 at 1:30
  • @Brad Nesom I suppose it depends on whether you need to keep a record of the method used to get the point. eg. for all our cadastre construction we keep a record of every line that was entered. If all you want is the point and don't need to prove how it was derived, 'point at end of line' may be sufficient. – Loz Nov 11 '11 at 1:43

I'm assuming you have bearings in your sketches to work out relative locations?? If so, could you not work out the location of the control point(s), work out the X and Y offset with some trigonometry, and therefore the co-ordinates of your RFID tag. You could then enter these into ArcGIS. You can do this manually using a button on the main toolbar with an XY and a circle below.

This may well be more accurate, not sure about more efficient. It could probably be scripted to make it faster - so you had a workflow of click on control point A, and enter angle and distance, and new point is created. Or enter control Point A and bearing and Control point B and bearing and find out where they cross.

I'll leave someone better qualified to advise on surveying methods...

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