This first map, is an actual scan off the Bonner Springs USGS Map, photo revised 1975. The boxed area is the approximate property lines. There was a street, which was added later in 1976, which is not shown on this particular map, but dead ends, at the northwest corner of my property. The placement of my telescope for occultations is at the southeast corner of the house. Coordinates were measured at 94.8932 West, 39.0579 North, 249.7 Meters.
This map, is from the Tiger Mapping Service (http://tiger.census.gov). By entering my coordinates, derived from the USGS map, the Tiger Map, shows placement by the red dot. My lot is 175ft, in the east-west direction and 100 ft in the north-south direction. The dot, shows the coordinated to be approximately 100 ft farther west and on the opposite side of the street (graphics and text by me).
Next is the Etak Mapping Service (http://www.etakguide
.com/#FindLocation). When inquired as to location via address input, showed the house 1-1/2 blocks farther east. It was in no way close to the correct position. I tried several other known addresses to see if maybe there was an error in positioning. All inquiries were between 1/2 to as much as 2 blocks off the mark!
Using the Etak Mapping Service, I placed the cursor as close to the location of my site as possible, and inquired as to the coordinates of that location. The coordinates were off .0066 degrees in longitude and .00017 degrees in latitude. This translates to 2.356 seconds of longitude farther east, and .452 seconds of latitude farther north. I would probably find this acceptable for total occulations, but for grazes, I would want closer reliability and would refer to the appropriate USGS map, which could give .1 second resolution.
I am interested in collecting other mapping sites, or seeing what other software programs are providing. If you have a favorite site, or favorite mapping software program you are using, please enter my site data, listed above, into your mapping site/software, and email me the results in the form of either a .jpg or .gif format graphic. I will place the graphic on this page, with the analysis.
If you have comments about this page, or would like to contribute YOUR analysis of the various mapping site/programs, please e-mail me, and I will be sure to include it on this page.
send email to: Rob Robinson