I think you are confusing scale factor effects of LDPs with those you get with state plane coordinates.?ÿ ?ÿ
Scale Factor effects with state plane are on the order of 1:10,000. That's 0.25' in a half mile. So, yes.?ÿ I can't live with that, either.?ÿ ?ÿ?ÿ
If you are using an LDP, and the scale distortion is 1:100,000, the difference between grid and ground is 0.03' in 1/2 mile. An LDP in Kansas, where the elevation factor is very consistent, would likely have scale distortions much smaller than that. CSFs on the?ÿ order of 1:300,000, or about 0.01' in a half mile, and better, would be common.?ÿ
LDPs are just smaller grid zones.?ÿ Instead of having one or 2 zones to cover your whole state you would have zones that cover 1 or 2 counties. Not exactly a tiny area. A guy like you, who doesn't want to work more than a half hour drive from your base, would probably never use more than one zone.?ÿ ?ÿ ?ÿ
Perhaps. I google "GPS for Land Surveyors pdf" and get a link. I see Amazon.ca wants $120 CDN for a print copy. Ouch.?ÿ The exchange makes that about $90 US. It's about $60 US for those of us south of the line.?ÿ?ÿ
Perhaps. I google "GPS for Land Surveyors pdf" and get a link. I see Amazon.ca wants $120 CDN for a print copy. Ouch.?ÿ The exchange makes that about $90 US. It's about $60 US for those of us south of the line.?ÿ?ÿ
Nothing new.?ÿ Nobody seems to want our "monopoly" money.?ÿ Though, when I go to the links in your pics I get a site that won't load and 2 links go to the same site that want me to buy ballet shoes.?ÿ Google play gives it to me for the low, low price of...........$114 USD............for the ebook.
Is that book you posted a worthwhile buy? I've heard some praise it and others say it was so-so but all of these people giving it reviews were just college students it appeared; not surveyors. Didn't want to buy something without having some real-world feedback
I frequently recommend GPS for Land Surveyors. So, yes, I think it is worth it. It's not perfect. It requires some effort to plow through. But I think it is the single best resource available on the subject.
Some have complained that it doesn't go into enough detail. My answer is that the book is notGPS for Astrophysicists.
I have the 3rd edition of GPS for Land Surveyors.?ÿ There is a lot of good information in it and you will probably learn a lot.?ÿ But it is not as well organized as I would like and not smoothly assembled into a coherent textbook.?ÿ Many statements beg for additional data, such as stating an accuracy of positioning without tying it to observation time, epoch rate, or distance from the base or CORS.?ÿ Various observation methods are listed without describing how they differ in the methods of processing the signals together to get a solution.
It doesn't seem to be carefully edited for clarity, or avoiding trivial errors and wrong word choices.?ÿ A silly example is the statement that it is advisable to limit GPS observations to signals 15% above the horizon, where it should probably say degrees not percent. It says that some of the telemetry words are used by the receiver to integrate itself with the navigation message.?ÿ What does integrate mean here? Obviously the word should be synchronize.?ÿ Subframe 4 contains information that helps a receiver relate UTC to GPS time.?ÿ Why not tell us this is the leap second count??ÿ The rate of GPS time is kept within 1 microsecond ... of ... UTC.?ÿ Rates are not measured in microseconds.
So yes, there is good information, but the little problems, unclear statements, and limited explanations annoy me to no end.
I had the author as one of my professors and he, not too surprisingly, made his book the class text book.?ÿ It was/is a good book, but I would be interested in alternatives.
The Leick book has not been updated since 2004, which is a long time with this technology. And it's a lot more about the inner workings of GPS and the math involved. May be heavy for the average Land Surveyor.
I downloaded a preview from Amazon, which basically gets me a look at the T.O.C.. It looks like it could be a good book, with a couple of caveats. It hasn't been updated since 2006, which is a long time. And while it appears to discuss projection systems generally it does not seem to describe the development of specific datums and projections of interest to US surveyors, or of any other country. And it's treatment of non GPS systems appears to be limited. Which is natural, these systems were quite limited in 2006.
On the flip side, GPS for Land Surveyors discusses the history, current status, and future of US datums and projections at length. It does not discuss any systems from outside the US. Which would limit it's usefulness to those living outside of the land of the free and the home of the brave.
