Coordinates converting to GPS format

[+beachkid]

On some maps and databases, I discovered two nearby benchmarks. Its coordinates are somewhat unusual to me and I had a hard time converting it to my GPS format (Degrees dd.dd) format. The designations of AZI and STA006-2001 listed can be search for in the Internet.

 

AZI006-2001 38 10 18.13375 85 46 53.61493

(aaannn-nnnn)

 

STA006-2001 38 10 29.67112 85 46 56.40500

(aaannn-nnnn)

 

I can read it as 38 degrees, 10 minutes but dd.ddddd as seconds?

 

Thanks,

 

Ken

[+Kewaneh & Shark]

Survey-grade GPS systems with sub-centimeter accuracy routinely output coordinates with the seconds to 5 or 6 decimals. More in some cases.

 

To convert a DD MM SS.SSSSS format to a DD MM.MMM format, divide SS.SSSSS by 60 to calculate the decimal minutes.

 

38°10'18.13375" --> 18.13375/60 = 0.302 --> 38°10.302'

85°46'53.61493" --> 53.61493/60 = 0.894 --> 85°46.894'

 

Converting minutes to decimal seconds can be done in a similar manner.

 

- Kewaneh

[tosborn]

Most GPS receivers allow you to set the format of coordinates (e.g. DDD.ddd, or D MM.mmm, or D M S.ss) for display and entry. Your's probably does also.

Edited December 20, 2006 by tosborn

[+NorthWes]

I dawdled my way through a net search for one of the marker descriptions and found a database (which you're probably using - the Louisville - Jefferson County Information Consortium page which has awesome tools for locating the county's own benchmarks) listing STA006-2001. While the other posters have given you an answer to your original question about the coordinate conversion, I'd like to point out that this station is apparently not in the USGS database used on the geocaching.com website. The same local county database referenced above includes HZ1042 - Louisville South Base RM1, and a search of nearby benchmarks on the geocaching.com website from HZ1042 didn't yield a listing matching STA006-2001 either by name or location.

 

The Information Consortium webpage is a great example of a GIS database being made available online for local users. It's disappointing for we 'benchmark hunters' to find such an excellent tool only to discover that many of the marks listed were not sent to the USGS for inclusion in the national database (for many many reasons). That doesn't by any means diminish the value of the local GIS database, as it's very useful for local GIS professionals. You've done a good job finding an internet information source for your own backyard - I didn't discover my city's online GIS resource until I'd spent a year chasing after benchmarks here!

[DaveD]

Just to keep things accurate geocaching.com does not use the "USGS Database." It uses the National Geodetic Survey (NGS) database. While the U.S. Geological Survey (USGS) did set of lot of survey marks, most of which were never submitted to NGS or it's predecessor agency, the U.S. Coast & Geodetic Survey (USC&GS), they do not maintain any form of a digital data base of their control marks.

[+beachkid]

It is funny you should mention benchmark for I discovered one some time ago. It is a City of Louisville (KY) benchmark numbered 20-4 with no elevation marking. It is a circular metal disc on a raised square concrete base about 3 inches high and on a five by five square concrete base. It is located just inside where the sidewalks of meet at Walter Avenue and Taylor Boulevard, southwest corner. My GPS marked its location as 38 10.54, 85 46.97 or 38 10' 32", 85 46'58". I have not yet find a listing for it anywhere yet.

 

I hope to find more if I knew how.

 

Ken

 

I dawdled my way through a net search for one of the marker descriptions and found a database (which you're probably using - the Louisville - Jefferson County Information Consortium page which has awesome tools for locating the county's own benchmarks) listing STA006-2001. While the other posters have given you an answer to your original question about the coordinate conversion, I'd like to point out that this station is apparently not in the USGS database used on the geocaching.com website. The same local county database referenced above includes HZ1042 - Louisville South Base RM1, and a search of nearby benchmarks on the geocaching.com website from HZ1042 didn't yield a listing matching STA006-2001 either by name or location.

 

The Information Consortium webpage is a great example of a GIS database being made available online for local users. It's disappointing for we 'benchmark hunters' to find such an excellent tool only to discover that many of the marks listed were not sent to the USGS for inclusion in the national database (for many many reasons). That doesn't by any means diminish the value of the local GIS database, as it's very useful for local GIS professionals. You've done a good job finding an internet information source for your own backyard - I didn't discover my city's online GIS resource until I'd spent a year chasing after benchmarks here!

[+beachkid]

Thanks for clarifying. What threw me was the extra decimal point in seconds field.

 

How were you able to make a degree mark when writing?

 

Ken

 

Survey-grade GPS systems with sub-centimeter accuracy routinely output coordinates with the seconds to 5 or 6 decimals. More in some cases.

 

To convert a DD MM SS.SSSSS format to a DD MM.MMM format, divide SS.SSSSS by 60 to calculate the decimal minutes.

 

38°10'18.13375" --> 18.13375/60 = 0.302 --> 38°10.302'

85°46'53.61493" --> 53.61493/60 = 0.894 --> 85°46.894'

 

Converting minutes to decimal seconds can be done in a similar manner.

 

- Kewaneh

[+Black Dog Trackers]

beachkid -

 

To make a degree mark, while holding down the Alt button, type 167 on the number keypad.

 

If you'd like to log what you find in the Louisville database that are not on the regular benchmark database, you may log them on the Recovered US Benchmarks site.

Edited December 20, 2006 by Black Dog Trackers

[+Kewaneh & Shark]

...How were you able to make a degree mark when writing?...

 

...To make a degree mark, while holding down the Alt button, type 167 on the number keypad...

 

I'm not that advanced. I usually just cut and paste the decimal from some other document or website.

 

- Kewaneh

[kayakingphotos]

...How were you able to make a degree mark when writing?...

 

...To make a degree mark, while holding down the Alt button, type 167 on the number keypad...

 

I'm not that advanced. I usually just cut and paste the decimal from some other document or website.

 

- Kewaneh

 

The ° is actually Alt + 176. The easy way to get this without having to find it in another document is to use Microsoft Windows "Character Map" (it is under the "Start" menu then "All Programs" then "accessories" then "system tools" (or so......)) You can use it to get whatever character you want. Like ± Æ Ă Ŧ ‰

 

Patrick

[+Shorelander]

What are you all talking about? You get a ° by holding Option+Shift+8.

 

Ohhhh.

 

Well, I'll sit over here with my Mac then.

[+Kewaneh & Shark]

...To make a degree mark, while holding down the Alt button, type 167 on the number keypad...

...The ° is actually Alt + 176....

What are you all talking about? You get a ° by holding Option+Shift+8...

 

I use a PC at work and a Mac at home. Cut & Paste works on both.

 

But lets keep it on topic folks. Divide your ALT & 'Option+Shift' codes by 60 to get their decimal ALT & 'Option+Shift' equivalents.

 

ALT 167 --> 167/60 = 2.783 --> ALT 2.783

ALT 176 --> 176/60 = 2.933 --> ALT 2.933

Option+Shift+8 --> 8/60 = 0.133 --> Option+Shift+0.133

 

... I know.... I'll be sitting over there with my scissors & glue....

 

- Kewaneh

Edited December 21, 2006 by Kewaneh & Shark

[+Klemmer]

OR----

 

You can use a REALLY small font size "o", and make it superscript. I've done it on some ancient word processors before things like an "ALT" key were invented. Worked fine on Wordstar on my 1Mhz cloned TRS-80 with the tape recorder for storage, or my Apple II with Appleworks and 5-1/4 inch floppies.....,

 

BTW: Still works in Word, but why..... I could do it here if I knew enough HTML......

[+Black Dog Trackers]

º o O o º

[Wintertime]

What are you all talking about? You get a ° by holding Option+Shift+8.

 

Ohhhh.

 

Well, I'll sit over here with my Mac then.

I had the same thought! Yikes, having to remember ASCII codes???

 

Anyway, I have another thought about the original question. The benchmark database on Gc.com is now, what, six years old? I wonder how many of those extremely accurate survey-grade GPS systems were even in use back in 2000. It's possible that the benchmarks "Beachkid" found are quite recent and thus didn't even exist when Groundspeak took its snapshot of the NGS database. Not that there aren't plenty of old benchmarks that never made it into the NGS database, but we're certainly seeing the two sets of information get further and further out of sync as time goes on, and this could be one of those cases.

 

Patty

Edited December 21, 2006 by Wintertime

[+Kewaneh & Shark]

º o O o º

 

Shouldn't this be...

º ho HO ho º

- Kewaneh

[+Kewaneh & Shark]

... I wonder how many of those extremely accurate survey-grade GPS systems were even in use back in 2000. ...

GPS has been used in survey applications since the early 90's, and maybe a bit earlier. It was primarily used in geodetic applications and large engineering projects. Back then, the systems were all survey grade. After the field work was completed, a large amount of data post-processing was required achieve the final results and positions. Cost reductions, fewer technical limitations, turning off Selective Availability (SA), and product availability have made its use commonplace today in nearly every aspect of the survey industry on just about every type of project, from the large projects to the small lot surveys.

 

- Kewaneh

[+Black Dog Trackers]

Kewaneh & Shark -

 

Cool Santa!

Edited December 21, 2006 by Black Dog Trackers