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National Geodetic Survey (NGS) FAQ


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Welcome to the National Geodetic Survey’s (NGS) Frequently Asked Question (FAQ) thread.

This FAQ is designed for beginners who are interested in submitting recoveries to NGS. There are a lot of question that routinely come up by people new to the idea of submitting recoveries to NGS. So before you make a new post in this forum asking a question, please take a minute to read through this thread. Your question may have already been answered.


Q: What is the National Geodetic Survey (NGS) and why does it have a separate forum?


A: NGS is a federal government agency within the National Oceanic Atmospheric Administration (NOAA). NGS is responsible for maintaining the National Spatial Reference System (NSRS) which is the basis for all mapping and surveying in the USA. For more information on NGS visit our webpage, www.ngs.noaa.gov

When geocachers search for “benchmarks” they are in fact searching for the objects that make up the NSRS. Many of these benchmarks were set in place and surveyed by NGS and are property of the federal government. When you submit a “find” to geocaching.com, NGS does not receive the report. Information about the status and, in some cases the position (more info below), of these marks can potentially be of value to the NGS and professional surveyors. By submitting a separate report to NGS, you can help maintain the NSRS and provide valuable information to future users. This forum was created by the founder of Geocaching.com to help assist in the maintenance of the NSRS.



Q: Do I have to log my finds with NGS?


A: No. Submitting a report to NGS is 100% optional. If you are just benchmark hunting for fun, and are not interested in submitting your data to the government that is fine. Have fun.



Q: Why should I log my finds with NGS?


A: Again, whether or not to log a find with NGS is up to you. You are never obligated to do so. However, in certain cases the information you find when looking for a benchmark may be valuable. For example, if you find a mark that has not been recovered in a long time or a mark that has been destroyed, that is valuable. If you find an error in the datasheet, or if you discover that something has changed in the description of how to find the mark, you have information that may be of high value to someone. By reporting it to NGS you are performing a valuable public service by sharing that important information with people who need it.



Q: Where do I submit reports to NGS?


A: NGS has an on-line mark recovery page. To submit a report, just visit http://www.ngs.noaa.gov/FORMS_PROCESSING-c...y_entry_www.prl



Q: I am not a professional surveyor. Am I qualified to be submitting a recovery report to NGS?


A: Yes. You do not need to be a surveyor to provide useful information. However, there definitely are a few things you should be aware of. Make sure the data you are submitting is accurate! If you are new at this you might want to hold off before sending in any reports of “not found”. You should know the difference between a reference mark and a triangulation station before submitting something dealing with that. There are lots of people in these forums who are happy to answer any questions you may have.



Q: I am submitting a recovery report and I want to know what is the official, exactly, legal, 100% accurate definitions of “good”, “poor”, “not found” and “destroyed”?


A: There are no official definitions. I am sorry, but you will have to actually use your own judgment here. Destroyed marks are handled separately and should not be submitted through the mark recovery page. Destroyed marks are handled by emailing Deb.brown@noaa.gov


Here are some guidelines used by NGS employees to describe the condition of a mark:


GOOD -- Recovered as described on the datasheet; looks healthy and happy.


POOR -- Recovered, but shows some alarming evidence of damage or movement. Often the marks can get run over, or frost heaved, or the ground is just too soft to support it. If the mark is scarred and leaning (i.e. the victim of a tractor-lawnmower), thrust up from the ground like a mushroom and/or surrounded by tractor ruts, it's poor. If the disk is gone but some evidence (stem) remains, then it could still be useful; that's a POOR too. Please describe the problem you see in the notes section of the report.


NOT FOUND -- I can't find it. Describe how hard you looked or confused you were, e.g., "not found after 10 minute search; unable to recover because all witnesses are destroyed" or "not found; existence doubtful, entire area is now a new shopping mall."


DESTROYED -- We prefer the more optimistic "NOT FOUND" unless you have direct first-hand evidence that the mark is completely obliterated. Getting a mark listed as destroyed requires submission of evidence (like a photo) and an e-mail.



Q. I heard the NGS said that they don't want benchmarks reported more than once a year. Does that mean I need to report them every year?


A. No. You need to use your judgment on when it is a good idea to submit a report. If the last time the mark was found was 20 years ago (or anything more than a few years), then yes, report it, even if nothing has changed in the description. If it was reported recently, but something major has changed, (it was destroyed, or the name of road it is nearby has changed) then report it to help someone else find the mark. Think about how you would feel if you had that data sheet and wanted to find the mark--if it was set in 1942 and there were no recoveries since, would you feel confident of being able to find it easily? On the other hand, if there was a 2005 recovery that stated that the mark was found as described, you would believe you could locate it with little problem.



Q. What sort of description changes should I report?


A. Any changes in the description should be reported. For example, changes in the name of the county, town or city where the mark is located. Maybe the “large Oak” the mark was in front of was cut down 5 years ago. Again, think of what YOU would want if you were looking for the mark. Measure from nearby landmarks--telephone poles, curb, road center, large trees, house corners, etc. If you find a change in a description, please report it regardless of when the last recovery was.



Q. Is there a difference between reporting to GeoCaching.com and NGS? Are the criteria for a find and a not found different?


A. Yes. Geocaching.com’s database is not used by professionals. The NGS database is. As such, we at NGS are pretty particular about what gets in. If you want to submit, you need to take the time to make sure what you are reporting is correct.

Other specific examples of difference between NGS and Geocaching.com


For a Found: GeoCaching.com wants to hear about every find. NGS only wants to hear about finds where the monument has not been found in 12 months or there is some change.

Not Found: For GeoCaching.com, this is a fairly casual rating. For NGS, professionals might spend extra time and money to use a more distant mark if they believe your report, so this rating shouldn't be given unless a serious and competent attempt was made to find it.


Destroyed: For GeoCaching.com, you are essentially recommending that hobbyists not waste their time looking for this. For NGS, the way to report it is different, and you are so sure it is destroyed, you are suggesting to professionals that they would be better off spending thousands of dollars establishing a new monument rather than bothering to look for the destroyed one.



Q. I found a mark and its LAT/LONG coordinates were way off. What is going on?


A. This is a bit technical, so please read carefully.


NGS has two different types of marks: Horizontal control marks, and Vertical control marks. The marks used for vertical (i.e. elevation) control often have a “SCALED” position. You can tell if this is the case by looking at the datasheet. A “SCALED” position means that the horizontal (LAT/LONG) coordinates were estimated using a map. In this case (and ONLY in the case), your handheld LAT/LONG coordinates are potentially more accurate than the position listed on the datasheet. In these cases you can record your GPSr coordinates for the mark and include them in the notes area of the NGS recovery form. Your coordinates will be used to help people find the mark in the future. Keep in mind that submitting handheld GPSr coordinates is totally optional. If you do chose to submit handheld coordinates you should know that NGS uses the NAD83 datum and coordinates are recorded as DD MM SS.S. Recovery reports which include GPS readings should conform to those standards.



Q. I happened upon a benchmark, but it isn't listed on Geocaching.com. Can I report it to the NGS?


A. The Geocaching.com database is not the same as the NGS database. If you are going to be submitting recoveries, please use the NGS database to check the most up to date datasheet before you submit a recovery.

Not all marks in the NGS database are in the Geocaching.com database. If you do find a mark, and can’t find it on Geocaching.com, use whatever information you have about the mark (such as its coordinates, station name, or county) to look for it in the NGS datasheet database. The NGS database can be found at http://www.ngs.noaa.gov/cgi-bin/datasheet.prl. If the mark is not in the NGS database, it won’t have a PID and you will not be able to submit a recovery.



Q: I found a PID a couple years or so ago and logged it on the Geocaching site. Should I submit a mark recovery on the NGS site?


A: That depends. Check on the NGS database (NOT the geocaching.com database) and see if the mark has been recovered in the part 12 months. If you choose to submit a mark recovery, in the entry box called "Enter date of recovery", you must enter the date you found the disk, not the date you submit the mark recovery.



Q: I found an error on the datasheet. What should I do?


A: We would love to hear what the error is. To report it, don’t submit an update, but instead send an e-mail to cheryl.malone@noaa.gov



Q: I have a question that is not addressed here, what should I do?


A: There are lots and lots of question that are not addressed here. This is just a basic FAQ. If you have any other questions, feel free to make a new thread and ask away. There are lots of helpful folks around here who are happy to answer your questions.


Thanks, and happy benchmarking.

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