Micropath Corporation

In 1983 Rocky Mountain Microwave began developing microwave path design software to generate path profiles and link analysis calculations. A few years later we did a name change to Rocky Mountain Communications since predicted area coverage (PAC) software was developed in order to support VHF/UHF repeater systems. In 1992 another name changed occured and Micropath was born.

Prior to the introduction of digitial elevation models (DEMs) in the 1980's, creating a path profile was sometimes a laborious process depending on the length of the path. One had to manually extract elevation points from USGS 7.5' topographic maps and calculate distances of each point from the starting point. Path profiles were plotted on graph paper or special earth curvature graph paper. Topographic maps were laid out on the floor and a string or board was used to draw a straight line from Site A to Site B. More path profiling sophistication evolved by developing an algorithm to calculate the 7.5' map latitude / longitude crossover points. Maps were then placed on a drafting table and the straight line of the path was drawn between map edges or from the map edge to Site A or Site B.

In the early 1980's, 30-second elevation data became available through a dial-up path profile service provided by the National Telecommunications and Information Administration (NTIA) in Boulder, Colorado. The horizontal resolution (approx 3003 feet) and the vertical accuracy of the DEMS were far from perfect but did provide a quick look at a proposed radio communications path.

During these years computer technology for the end user was rapidly developing with terminals, PC's, and graphing plotters. By 1984 path profiles were being plotted on equipment such as the HP7475A and HP7476 plotters - provided someone wrote the software. Fortran, Basic, and C were the programming languages.

Circa 1990 3-second DEMs were being produced and sold by the USGS. Source of the 3-second data was the 1:250,000 scale USGS topographic maps. The data was delivered on 9-track tapes. The original USGS 3-second data provided new insights into digital path profiling but the 303-feet horizontal resolution and vertical accuracy of the elevations (1:250,000 scale maps) was not perfect. Critical points along the path still had to be verified against the 7.5' topographic maps.

By 1994 the 7.5' 30-meter DEMs were produced and sold by USGS. There were approximately 66,000 7.5' DEM files for the United States. 30-meter DEM coverage was good but there were occasional holes or gaps in the data coverage, especially in New York and New Mexico. USGS was now producing the 10-meter DEMs but only for selected areas and to fill in the missing 30-meter DEMs. By 2000 there may have been about 12,000 10-meter DEMs produced in relation to 66,000+ 30-meter DEMs. Fortunately, a higher degree of confidence in the accuracy of digitally produced path profiles came with the use of the 10/30-meter DEMs.

Around the year 2000 USGS introduced the 1-arc second National Elevation Dataset (NED). NED was a seamless dataset that spanned the USA. NEDs were produced from the best available data, i.e., mainly from the NAD27 10/30-meter DEMS. The 10/30-meter DEMS were reprojected to NAD83 (WGS84). NED 1, 1/3, and 1/9 arc-second data are available in the public domain.

Also during this time the Space Shuttle mapped the earth and the SRTM 3-second elevation data become available for most of the world. SRTM 1-second data for the USA was also produced.

Google has become a recent entry into the world of digital elevation data. Although Google doesn't provide any information about the source of their digital elevation data it is believed the Google Elevation Data Service incorporates the best available data into their elevation data product. Coverage is worldwide.

About Us

Micropath Corporation - The beginning and a brief history of path profiles and digital elevation data

Micropath Today