UNMAS IATG Quantity Distances (UNMASQD)

This page describes a free application that runs in the Google Earth desktop client. Please install Google Earth, download UNMASQD, and return to this page to learn more.

Metzger + Willard, Inc. is proud to support the United Nations Mine Action Service (UNMAS) in their efforts to free the world of landmines and other unexploded or abandoned ordnance. UNMASQD is an online tool that draws concentric circles in Google Earth at selected levels corresponding to International Ammunition Technical Guideline 02.20 (IATG) Quantity Distances (QD) for Hazard Division (HD) 1.1. Distance calculations are based on an open stack as potential explosion site (PES) with formulas from IATG Table 8 and appropriate minimum values from Table D.1.

  1. Position the PES in the center of the view. One way to do this is to double-click an unmarked location. To precisely position the PES in the center of the view, add a placemark at the desired location; then edit the properties of that placemark and reset the view (explain). For best results, disable automatic tilting (Tools, Options, Navigation, Do not automatically tilt while zooming) and minimize elevation exaggeration (Tools, Options, 3D View, Elevation Exaggeration, 0.01).
  2. Check the box beside the Setup network link. A form will be presented with read-only coordinates corresponding to the view center, input fields for Net Explosive Quantity (NEQ), PES name, and checkboxes for eight QD levels in HD 1.1. QD rings are drawn when the Draw button is pressed.
  3. On subsequent uses, reposition the PES and ensure that the network link is checked and selected. Then choose Refresh from the Edit menu, or right-click and select Refresh in the context menu (explain).
© 2014 Google - Image © 2014 DigitalGlobe

These calculated distances and the drawn circles are meant to be a quick, descriptive measure to estimate quantity distances for advocacy purposes. The actual calculations for the licensing of storage sites or the planning of Ammunition Storage Areas must be done by a qualified Ammunition Technical Officer according to the relevant IATG.

QD rings are rendered as regular polygons with 72 vertices on the WGS84 ellipsoid using Vincenty's nested equations. The calculated vertices typically exhibit submillimeter agreement with the NGS online Inverse/Forward computation utilities.

Note: To save QD rings from one Google Earth session to another, right-click on Saved Sites and select Save to My Places.