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I'm working with 19th century land tax records that provide a direction (expressed as NW, SE, etc.) and a distance in miles from the court house. The info in the Land Tax Records (LTR) is in effect a version of polar radiation. For each reading you start at the court house as your 0,0. The records have: LastName; Direction, Distance or LastName, Distance, Direction. Such as Smith, 4, SW that translates to Smith, 4 miles southwest of the court house.

Is there a way to place a symbol/marker/whatever at that point using QGIS 2.0? The end result should roughly result in the shape of the county in 1860.

It is possible and very cumbersome to do that with CAD by using the direction and distance alignment on a line and then placing a loci at the end of it. I can use the direction and distance measures by placing them into Excel, plotting them in Vectorworks, and then exporting them to QGIS. I'm trying to cut out the intermediate steps by having QGIS do the work. I can convert the directions to azimuths in Excel and the distances to whatever I need. But having 400 separate lines for a county is cumbersome if there's a more elegant solution.

Chris W
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Lyle Browning
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    Can you please specify the software you want to use? Depending on what CAD you're using, it shouldn't be that cumbersome. In AutoCAD You can draw a line by typing @0,0 for the start point at origin, and then (if you have the units set up right) using polar input @bearing,distance. The method is similar in ArcGIS, though with the right tools you can shortcut some things. Do you have specific bearings or just cardinal directions as you have typed in the question? The results are going to be very general if so. – Chris W Jun 12 '14 at 00:01
  • Bearing/distance is a common coordinate expression for survey information. ArcGis has the traverse tool http://resources.arcgis.com/en/help/main/10.1/index.html#//00wp00000043000000 that I have used to input cadastral plans manually by bearing/distance. Other GIS packages may have similar. – Michael Stimson Jun 12 '14 at 00:49
  • See http://gis.stackexchange.com/questions/81812/cogoing-legal-descriptions/81944#81944, http://gis.stackexchange.com/questions/99581/data-format-for-checking-a-land-survey-deed and http://gis.stackexchange.com/questions/99606/how-to-enter-quadrant-bearings-into-copan-map-check?lq=1 – Martin F Jun 12 '14 at 04:35
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    Note the asker does not describe having a traditional traverse or metes and bounds description, but rather a polar coordinate array. Based on asker's other questions he is using QGIS, and if confirmed then this question would be a duplicate of http://gis.stackexchange.com/questions/76077/how-to-create-points-based-on-the-distance-and-bearing-from-a-survey-point?rq=1 – Chris W Jun 12 '14 at 06:02
  • When the Comments are far longer than the Question, to me it suggests that the asker should edit the Question to revise it with clarifications. – PolyGeo Jun 12 '14 at 07:32
  • I am using QGIS 2.0. I can use the direction and distance measures by placing them into Excel, then plotting them in CAD (Vectorworks) and then exporting them for QGIS. I'm trying to cut out the intermediate steps by having QGIS do the work. I can convert the directions to azimuths in Excel and the distances to whatever I need. But having 400 separate lines for a county is cumbersome if there's a more elegant solution. – Lyle Browning Jun 12 '14 at 15:29
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    Please post a sample of your raw data -- type or scan some -- because your problem description is unclear. – Martin F Jun 12 '14 at 17:29
  • @ChrisW: What is a "polar coordinate array" or how is it different from traditional metes? – Martin F Jun 12 '14 at 18:51
  • @martinf Traditional metes starts at a point and navigates a traverse from one point to the next. A polar coordinate array gives all calls as bearing and distance from a single origin. There's a good graphic example in this question. – Chris W Jun 12 '14 at 19:33
  • I would have called it "polar radiation" or "radial ties" (i don't think there's an agreed, common term). Either way, i don't see how we can conclude that's the kind of data from the Q's wording. – Martin F Jun 13 '14 at 15:31
  • The info in the Land Tax Records (LTR) is in effect a version of polar radiation. For each reading you start at the court house as your 0,0. The records have: LastName; Direction, Distance or LastName, Distance, Direction. Such as Smith, 4, SW that translates to Smith, 4 miles southwest of the court house. – Lyle Browning Jun 13 '14 at 19:23
  • You should use the edit button bottom left of your question to add information requested by comment rather than another comment. It saves reading a long chain to get necessary information. Also, putting @name (see above) in a comment notifies that person you have left one. There are possible answers for this at the duplicate I mentioned earlier or (if the math works) as an answer here. However since it appears you have only cardinal directions and not specific angle bearings, your points are all going to fall on one of 8 lines (assuming they don't go to 16 by using S-SW or NW-E, etc.). – Chris W Jun 14 '14 at 05:01

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In the Excel spreadsheet I'll add a column for each register for X and Y (or longitude and latitude). I calculate this cells with

X = Xcourt house + distance * sin(bearing or direction)

Y = Ycourt house + distance * cos(bearing or direction)

Then I'll export to a CSV file and import it to QGIS with delimited-text-file icondelimited text file. If you put on CSV file headers "X" and "Y" fields QGIS recognizes it and get that directly to coordinates.

After that you could save to a .shp or whatever.

Fran Herranz
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