Angular measurements are supported in both Deg-Min-Sec and GONS. STAR*NET can reduce observations to NAD27, NAD83 or UTM with separate grid factors calculated for all distances and t-T corrections calculated for all angles.Ĭustom Transverse Mercator and Lambert grids may be defined for special local requirements or for grid systems in most areas of the world. Whether a survey consists of a single-loop traverse or a complex network of interconnecting traverses, all observations are adjusted simultaneously to produce a single best-fit solution. Differential levelling observations can also be included within a 3D adjustment. STAR NET handles networks containing conventional observations combined with GPS vectors, with up to 10,000 adjustable stations.

What values you use for centering error must be based on equipment, field conditions, your crew and experience.MicroSurvey STAR NET 9 is an easy-to-use Windows application that adjusts 2D/3D survey networks using rigorous Least Squares techniques. Target centering depends on the kind of target and care used in setting up. As a rough guide, for instrument centering error we find values around 0.005 feet (0.0015 meters) commonly used for optical plumbs, and 0.010 feet (0.003 meters) or more for string plumbs. These values are used to inflate the standard errors of horizontal angles, directions, distances, and to some extent, observed zenith angles. Horizontal and Vertical Centering - This is an estimate of the horizontal and vetical centering error, the inability to center over a mark. 1 Sets (1fs+1bs) with a 1' second gun is:Īnother example: 3 sets (3fs+3bs) with a 5 second gun is:ĭirection Accuracy - Is the DIN 18723 specification for Theodolite Accuracy applies to a repeated FACE 1 and FACE 2 pointings. In the example left, you would enter 0.016 feet for standard error, and the same 3 ppm.Īngle Accuracy - The Angular Accuracy = 2 x (DIN 18723) / Square Root of the Number of Pointings. Remember, if your project units are set to feet, you have to convert any millimeter rating to feet. Say for example your EDM is rated as plus or minus 5 millimeters, and plus or minus 3 ppm, you would enter the value 0.005 meters (assuming your data is in meters) in the distance standard error field previously described, and the value 3 in the ppm field. A value entered here represents the proportional distance measuring error of an EDM in parts per million. Here is also an article which may be of use to you.ĭistance PPM - The actual standard error used for the distance observation is made up of two parts, the constant and the proportional (distance times ppm).

Microsurvey starnet traversing settings