With just a few days before we head off to Alaska I don’t really have time to be playing with JOSM but I’m waiting for a terabyte of data to backup while I update my OpenFiler NAS, so I was browsing the JOSM Plugins catalogue and came across FieldPapers.org.
What intrigued me is that the home page gives you very little clue as to what the service is and how you might use it, but this page on Learn OSM Surveying with Field Papers is very informative.
I’m sure there are other reasons you might want to download a PDF of A4-size tiled extracts of OSM mapping data, but it seems the main purpose is to help OSM contributors collect data in the field and then easily upload it.
FieldPapers.org allows you to scan in sketches, notes and points marked on printed maps and then georeferences them using a geocoded QR code and calibration marks on the edges of each printed map which you can then import into JOSM and use it as an underlay.
I tested it out on the Kenai Peninsula in Alaska which is where we’ll be spending most of the next three weeks. You’re unlikely to be working at this scale so not as likely to come across this issue, but the UTM grid overlay is a bit dodgy:
The other app I discovered was Harcourt Traverse & Surveying after spending hours trying to find an easy way of calculating the coordinates of where two paths projected from polar coordinates bisect, so bearing 1 from coordinate 1 intersecting with bearing 2 from coordinate 2.
This is useful for triangulating landmarks and position fixing for navigation either without a GPS or for waypointing distant objects to then navigate to. It’s also of course useful in surveying, which is something I dabble with using my Brunton Transit compass and Nikon Forestry Pro laser rangefinder.
Surveying with a GPS is easier and can be quicker for small areas but does require you to physically move the GPS device around the perimeter of an area or hold it over waypoints.
A common example used in regards to triangulation is locating bushfires where two or more viewing watch towers of known coordinates will combine their bearing readings to triangulate the position of the fire.
Harcourt Traverse & Surveying allows you to enter the data points as zoneless UTM easting and northing or bearing and distance projections from existing points and then review the data in a map view.
This example shows survey data I collected at Millpost Hill in Womboin NSW and includes three GPS points plus several ranged and non-ranged (arbitrary distance) projected points which I’ll then consult when updating OpenStreetMap:
It’s only been out a few months and needs some work on the usability of data entry but otherwise it’s really quite cool with lots of features that I’ll find useful in addition to intersect finding like point and line offsets, midpoint (two-point average) finding, KML import (though I’d really love KML output!), calculators and other translation tools.
The app developer has been very quick to respond to my feedback and is open to suggestions and ideas, so I expect this app will improve greatly over the next 6-12 months.
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