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Satellite Usage

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From the NGS Mark Recovery Entry page:

Generally, a station is suitable for satellite observations if there is a clear and unobstructed view of the sky from approximately 15 degrees above the horizon at the location of the station. Small objects such as a light pole or small tree are excepted.

 

Is this station suitable for satellite observations?

Yes No Don't know

 

When logging a find on the NGS website, this screen always comes up when logging a good recovery. How does one determine the suitability for satellite observations? The "general" rule of 15 degrees above the horizon is rather vague. Does this just include disks? Or do water towers, church steeples, and radio towers also count?

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If you aren't sure, it is fine to enter "Don't Know". In many cases an informed amateur can make a good call, but some are too close to be sure and it is probably better to let a pro make the call.

 

The idea is that a surveyor should be able to set up their equipment over the location and get essentially uninterrupted coverage as satellites move across the sky. If the object is a tower or church spire, they aren't going to be able to readily set up equipment, so these are not suitable.

 

If a clump of trees hides a significant part of the sky as seen from head height over a disk, or the location is close to a building, then it is not suitable. If there is one tree that interferes but not a lot, then I might not make the call.

 

Objects on the northern horizon might not be as serious as on the east or west since you usually don't have satellites low in the north. Metallic objects are a bigger problem than a wooden pole because they have more effect in blocking or reflecting the signals.

 

It has been suggested that for most people 15 degrees is about the length from the little finger tip to the thumb tip when the hand is fully open at arms length. This gives you a way to estimate whether the equipment can see over nearby obstacles.

 

There was a thread on this about last month that you might want to search for.

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Suitable for statelite observation is for use by surveyors. It means that you can set up a tripod on the site and see all the SV's. In other words, mark should be out in the open, not under trees or next to tall buildings. While they did occupy the Washington Monument with GPS, it was a one in million chance when the were doing restoration and the scaffolling was in place.

 

Also just because the mark it open does not mean it would be suitable. No one is going to use a mark in a dangerous location.

Edited by Z15

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The fact that this question keeps coming up on this form indicates that the NGS web pages needs a little clarification. Especially since they take input from the general public.

 

This topic was discussed a few months ago in the thread titled Suitable For Satellite Observation?

 

You may find some additional info to help answer your question there. (Others of us may want to forget that thread.)

 

- Kewaneh

 

When a newbie ask questions on a forum I have more knowledge about I answer with respect and in a manner that will help the poster learn. Not everybody does that here and it detracts from the quality of this forum. No one is knowledgeable about everything.

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The fact that this question keeps coming up on this form indicates that the NGS web pages needs a little clarification. Especially since they take input from the general public.

 

This topic was discussed a few months ago in the thread titled Suitable For Satellite Observation?

 

You may find some additional info to help answer your question there. (Others of us may want to forget that thread.)

 

- Kewaneh

 

When a newbie ask questions on a forum I have more knowledge about I answer with respect and in a manner that will help the poster learn. Not everybody does that here and it detracts from the quality of this forum. No one is knowledgeable about everything.

 

The fact is that the original intent of NGS for setting up the station recovery pages was for professional surveyors to report their findings to other profession surveyors and Government agencies who at one time long ago reset some stations that were destroyed. I don't believe it was ever envisioned that the general public would have any interest in recovery survey monuments. The question of "Suitable For Satellite Observation" in many cases is a no brainer for any surveyor who has conducted any static sessions, especially if the station in question was occupied. Any surveyor with GPS experience knows exactly what they are asking. The very fact that someone asks this question means they aren't qualified to answer it and should probably respond "I don't know". That said I think the survey community values the efforts of the general public in taking their time to recovery survey monuments.

 

I have found Kewaneh to be a very informative and valuable contributor to this forum and fail to see any of his posts as disrespectful, having read the thread in question I can see how he could be frustrated by it.

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I have found Kewaneh to be a very informative and valuable contributor to this forum and fail to see any of his posts as disrespectful, having read the thread in question I can see how he could be frustrated by it.

 

Agreed. If Kewaneh was frustrated by my post in that thread I apologize. I was also frustrated, not by Kewaneh.

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The fact that this question keeps coming up on this form...

 

I'll agree that this question has been asked in this forum before. I'll also agree that a well intentioned question deserves an honest and respectful answer. My link to a previous thread with a similar discussion was not meant to be disrespectful of the OP's question, only to save some time for the OP and the others who may be answering. My intent was not to say, or to be interpreted to say, 'Search the forums before posting another question that's already been asked'. I am a member of forums on other websites of varying interests and they are full of older (and domineering) members who are quick to suggest to newbies to search every topic and read many years of posts before even thinking posting a question, rather than answering the question or politely showing how or where to find a suitable answer. It does make for a hostile environment and is not hospitable to those who have the desire to learn about a certain subject.

 

It should also be noted that I was not the first reply to mention the previous thread. The first person to reply, Bill93, answered the OP's question and mentioned the previous thread. I just provided the link to that thread and mentioned additional information.

 

... indicates that the NGS web pages needs a little clarification. Especially since they take input from the general public. ...

 

This may be true. But it should be remembered that while the Geocaching.com website is a hobbiest's site, the NGS site is most generally intended for professionals in the geodetic, surveying and engineering communities. It is also maintained by professionals for that purpose. Stvanme also mentions this in his post.

 

... The fact is that the original intent of NGS for setting up the station recovery pages was for professional surveyors to report their findings to other profession surveyors and Government agencies who at one time long ago reset some stations that were destroyed. I don't believe it was ever envisioned that the general public would have any interest in recovery survey monuments. ...

 

The data contained in the NGS database is, for the most part, public information, although its primary target audience is geodisists and surveyors, et al. As it is public information, the NGS does readily accept input from the public, and is very appreciative of the input it receives from the public at large, especially the GEOCAC community. When possible, the NGS does make changes to its format to be more user friendly. In fact, it is my understanding that the change that the NGS has recently made to accept new coordinates for a benchmark from a handheld GPSr is partly due to the GEOCAC community.

 

... When a newbie ask questions on a forum I have more knowledge about I answer with respect and in a manner that will help the poster learn. Not everybody does that here and it detracts from the quality of this forum. No one is knowledgeable about everything.

 

To repeat what I said above: I'll also agree that a well intentioned question deserves an honest and respectful answer. That is whether the person asking the question is a newbie or a forum veteran. In this case, Web-Ling is far from a newbie. (In fact, he joined in the Geocaching.com membership nine days before I did.) By linking to the previous thread, I intended to give helpful direction to provide an answer of his question. In the discussion that took place in that thread, many knowledgeable people offered answers and insight to a similar (if not same) question. Rather than repeat the discussion, a re-visit seemed appropriate. The previous thread is not locked, nor is it particularly old, and if more discussion is needed, it can continue.

 

There was no disrespect intended to anyone, in either this thread or the thread I linked to. If I was disrespectful in any of my comments, please let me know and I will do my best to refrain from using similar comments again. At this point, I can only assume that a disrespectful tone was taken with my comment about 'Others of us may want to forget that thread'. That was intended to be jestful comment and I count myself among those others, realizing that I may be a lone 'other'. As well intentioned as I was in answering the posed questions, I can see that in some cases I may have done more harm than good by creating more questions than I answered. My hope and intent is to add to the quality of this forum with my input, not detract.

 

I will agree that 'No one is knowledgeable about everything', myself included. I have, however, been working in the surveying profession for the better part of two decades, and have been able to learn a few things. I enjoy sharing those things I know with others when they ask, and do my best to deliver said answer in an understandable and respectful manner, tech-speak notwithstanding.

 

- Kewaneh

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Kewaneh,

 

Your posts are excellent, well thought out and helpful. The part about “Others may want to forget…” I missed that it was meant in jest and I apologize for that. I have fallen victim of that myself and find I need to use those blasted emoticons or smileys when I attempt humor. I did not think that you were brushing off the OP or disrespectful in any way.

 

I understand the point that the NGS web site was written for professionals by professionals. But they did open it up to the general public to update the database and that’s where the trouble begins.

 

I just retired after 38 years working with gun and missile fire control and weapons systems, search radar and electronic countermeasures aboard Navy ships and submarines. I tend to think of myself as above average technologically speaking. But I was wrong about the meaning of the question. I feel I was partly led astray by Google (and others) and their aerial photos they label as satellite. I know I looked at a couple of benchmarks in Google to see how well the area around the mark looked.

 

My underlining concern here is the integrity of the NGS database. Now there are some stations out there that are labeled as suitable for satellite observation that may not really be suitable. Some professional may spend time and money to go out to the station only to find out the database is wrong. I think answering this question correctly is just as important as the destroyed/not destroyed question that is being debated in other threads.

 

Thank you for using your years of experience and knowledge to help us newbies.

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