ngs read 3

[+goonybird]

I must admit to being a little confused by the output of ngsread 3

 

I'm trying to determine from the cryptic codes in the description field of the gpx files ngsread genereates,

whats a benchmark disc, what's a landmark, etc

 

FOr my county, one or two of the codes seem kind of obvious. one has for example "bridge" listed in the description.

 

Most have description entries like:

 

3 B 64

B 749

N 130

 

The gps TYPE field - most have Scaled Or adjusted - one has NO CHECK. a few have reference to "posotion calculated"

 

ANyway - without reading all the esoteric eggheaded docs at the NGS website - can someone stear me to decyphering these codes? and perhaps the correct commandline option to perhaps limit the gpx output to specific types?

[+Black Dog Trackers]

Hi goonybird -

 

Well that would be my cryptic writing, but not all.

For instance the description of marks you're referring to are NGS marker types listed in their publication here. Those are the common types of markers. The ones in the middle column that start with a D are the disk types. There are even more types than the list has and they are just described in the text instead of having a code.

 

The items you mention like "B 749" and "N 130" are the station names. It's true that they're usually cryptic - they're just serial numbers really. For instance, some surveyors might be paid to do a survey down a road. They might call it the "N survey". Individual stations would be called "N 1", "N 2", "N 3", etc. up to maybe "N 300". Often many are gone, so the ones left seem to skip a lot of numbers, and others never made it into the NGS database although they really are there on the ground.

 

Scaled and adjusted are explained here. The "NO CHECK" is one of the more esoteric classifications that I know nothing about. The "position calculated" is something I did - for reference marks I used some math to calculate the positions just to be able to show them on a map.

 

To limit ngsread's output to specific types of markers, use the /codesin thing on the command line. For example if your ngs file is ak007.dat and you want to limit to azimuth disks and magnetic stations use:

ngsread /codesin=DZ,DM ak007.dat

[Wintertime]

For instance, some surveyors might be paid to do a survey down a road. They might call it the "N survey". Individual stations would be called "N 1", "N 2", "N 3", etc. up to maybe "N 300".

Or sometimes, they keep the number the same and change the letter, such as the "715" series in Yosemite that has T 715, U 715, V715, etc.

 

Patty