Land Surveying Research Tools
Earth Survey is a collection of geodetic tools that run in Google Earth. Most of the applications have geographical extents associated with the United States, but MagDec, RINGS, and XYZGE work anywhere on the globe, while HCBM will be of interest primarily to Central Florida surveyors.
QUADS and PLSGE provide easy access to data and image services from the USGS and BLM, respectively. NGSCS is a graphical front end for the NGS station list utility, and seven of the tools (DeflecGE, GeoidGE, MagDec, NADGE, SPCGE, VERGE, and XYZGE) are graphical front ends for programs from the NGS Geodetic Tool Kit.
Download the Earth Survey Shortcut for easy access to Earth Survey tools from the Google Earth embedded web browser. To preserve the shortcut from one Google Earth session to another, right-click on Earth Survey and select Save to My Places.
DeflecGE is a graphical front end for the NGS online tool, DEFLEC12B. It eliminates the need to input geodetic coordinates and displays the deflection of the vertical and horizontal Laplace correction in a placemark balloon. Uses of vertical deflections include geodetic to astronomic coordinate transformation and astronomic to geodetic azimuth conversion.
ESMobile is a collection of tools that run in Google Earth 6.2+ on an Android device with OS 2.1+ or an Apple iDevice. A Wi-Fi or 4G Internet connection is recommended. Earth Survey applications that were written for the desktop will not run on a mobile device because of user interface, feature, and style differences. The tools listed here are components from HCBM, NGSCS, PLSGE, and QUADS that have been modified to run on a tablet or smartphone.
GeoidGE is a graphical front end for the NGS online tool, GEOID12B. It eliminates the need to input geodetic coordinates and displays the converted height, geoid separation, and scale factor in a placemark balloon. Both ellipsoid-to-orthometric and orthometric-to-ellipsoid height conversions are supported.
HCBM is a Google Earth KML document that plots the approximate location of Hillsborough County benchmarks from the LABINS database. All station balloons have links to the corresponding LABINS datasheet, and stations with an NGS PID also have links to the NGS database.
MagDec is a graphical front end for the NGDC online Magnetic Field Calculators. It eliminates the need to input geodetic coordinates and displays the calculated magnetic declination and secular variation in a placemark balloon.
NADGE is a graphical front end for the NGS online tool, NADCON. It facilitates the entry of geodetic coordinates and displays the converted coordinates and datum shift in a placemark balloon. Both NAD83-to-NAD27 and NAD27-to-NAD83 coordinate conversions are supported.
NGSCS creates Google Earth network links that plot the approximate location of NGS control stations within a specified distance of the view center (Radial Search), within the viewer bounding box (Rectangular Search), or within a selected county (County Search). Station balloons contain all information supplied by the NGS station list server and a link to the full NGS datasheet.
PLSGE is a Google Earth implementation of the Bureau Of Land Management (BLM) GeoCommunicator map service. It retrieves multiresolution images of the BLM Public Land Survey System (PLSS). PLSGE also includes a section geocoder and an implementation of the GeoCommunicator Identify service.
QUADS is a Google Earth network link that plots approximate USGS quadrangle boundaries and provides direct access to 121,593 GeoPDF maps, including scans of the last historical paper map in all available grid sizes. QUADS also includes overlays for topographic-bathymetric, hydrographic, and shaded relief maps.
RINGS is an online tool that draws concentric circles, an annulus, or a sector in Google Earth. Ring radii may be specified from 10 to 1,000,000 US survey feet or meters, and from 0.25 to 10,000 miles (1 mi = 5280 US survey ft), nautical miles (1 nmi = 1852 m), or kilometers. Line and area colors are selected from a 24-color palette, line width may be specified from 0.1 to 10, and area opacity may be specified from 0 to 100%.
SPCGE is a graphical front end for the NGS online tool, SPCS83. It eliminates the need to input geodetic coordinates and displays the converted coordinates, convergence angle, and scale factor in a placemark balloon. Both geodetic-to-plane and plane-to-geodetic coordinate conversions are supported.
VERGE is a graphical front end for the NGS online tool, VERTCON. It eliminates the need to input geodetic coordinates and displays the converted height and datum shift in a placemark balloon. Both NGVD29-to-NAVD88 and NAVD88-to-NGVD29 orthoheight conversions are supported.
XYZGE is a graphical front end for the NGS online tool, XYZ. It eliminates the need to input geodetic coordinates and displays the converted coordinates in a placemark balloon. Both geodetic-to-Cartesian and Cartesian-to-geodetic coordinate conversions are supported.