Surveyor Tool

Lunar Map Pro^TM is built on a state-of-the-art (GIS) Geographic Information System that understands the relationship between the flat map and the spherical surface of the moon. When features and distances are measured, the software automatically adjusts for the distortion of the spherical surface, caused by the (flat) projection, and produces an accurate result.

The Surveyor Tool gives you the ability to quickly and accurately measure the length of valleys, the diameter of lunar craters, and the distances between lunar features, by selecting two map points.

You can also click multiple map points to accurately measure along curved features such as rilles, dorsa and mountain ranges, or to find the perimeter of features.

EXAMPLE 1: Measuring the Crater, Maginus.

It is best to zoom-in first, since enlarging a feature improves the accuracy of your result. Click on the Surveyor Tool to display the dialog box, and click the button that says, Measure with Mouse. Help hints will then appear in the lower box. Next, click the outer edge of two sides of the crater, and the software will draw a line between the points.

When you click the Calculate Distance Button, the Latitude and Longitude of both points is displayed, and the feature measurement is entered in the display window, along with the diameter in arc seconds, and the Azimuth of the line. As you can see, the crater measures about 100 miles in diameter.

If you would like the measurement data in the display window to also appear on the map, check, Display Labels.

To measure a new feature, click Clear, and repeat the above procedure.

EXAMPLE 2: Measuring the Crater, Ansgarius.

This next example demonstrates how smart the software is. Ansgarius, is located near the moon’s eastern limb. Limb craters are extremely difficult to measure because they appear very elongated. This is the result of observing the craters at a highly oblique viewing angle. The Lunar Map Pro^TM advanced GIS technology has the ability to mathematically compensate for the angle of view, and calculate the dimensions correctly. Despite the crater’s elongated appearance, you can see from the calculations below, that the crater is actually circular, with a diameter of about 57 miles.

EXAMPLE 3: Measuring Dorsum Von Cotta.

If you want to measure a feature having an irregular appearance, such as Dorsum Von Cotta, you can click several points along the feature. When you click Calculate Distance, the distance between the points is added together, and the total is displayed in the lower window.