Talk:Real-time kinematic positioning

Error

Seems like there is an error in this text:

"In general receivers are able to align the signals to about 1% of one bit-width[1]. For instance, the C/A signal sent on the GPS system sends a bit every 1/10th of a microsecond, so a receiver is accurate to 1/100th of a microsecond, or about 3 metres in terms of distance."

Getting rid of the fractions by using nanoseconds makes it easier to follow. Converting to nanoseconds the text says that the bit time is 100ns. Thus 1% of the bit times is 1ns. The text goes on to say the receiver is accurate to 10ns. Something is wrong here. The bit time, the % of the bit time, and the accuracy don't match. 67.142.130.29 (talk) 07:10, 12 February 2008 (UTC)

Hydrographic survey

I added a note that RTK is used in hydrographic survey (as well as land survey as was previously specified) - this is my background, and we use it regularly. It's only possible of course when you are within range of a base-station situated on land or on a static offshore installation such as an oil platform. Girth Summit (talk) 21:48, 29 July 2008 (UTC)

mangano rtk

mafia of the liberty tré organiser pré a conquérir un collége —Preceding unsigned comment added by 193.251.180.167 (talk) 12:28, 17 June 2009 (UTC)

RTK's origins

This article should probably make reference to Dr. Benjamin Remondi. He is considered by most people in the industry to be the "Father of Real-Time Kinematic Survey" and invented most of the techniques that are still used by people doing RTK today. See: https://www.ion.org/awards/2003-ionfellow-Remondi.cfm.

Here is the abstract from Using the Global Positioning System (GPS) phase observable for relative geodesy: modeling, processing, and result from some of his work in 1984:

After removing the modulation from the Global Positioning System (GPS) signal (L1 or L2) a pure carrier signal remains. Suppose this carrier is continuously and precisely tracked by a GPS receiver. Furthermore, suppose the phase of the carrier is periodically measured and recorded (nearly simultaneously at two or more locations) with respect to receiver oscillators having the same nominal frequency as the GPS carrier. This paper first considers alternative modeling and processing approaches to these observational data for static operations. Then an approach to dynamic relative positioning using triple differences is presented. This approach should lend itself to performing centimeter accuracy relative surveys in seconds rather than hours. An approach to fixing cycle slips, automatically, is included. — Preceding unsigned comment added by 98.218.152.99 (talk) 04:32, 7 February 2012 (UTC)

Corrections Needed

There is some good information in this article, but much of it is erroneous. I am not qualified to correct it, but certainly somebody out there is.

For starters, RTK is not “a technique used to enhance the precision” at all. RTK is about getting real-time correctors which in turn supports knowing the position of the receiver instantaneously even while on the move (kinematic), hence Real-Time Kinematic = instantaneous on the move GPS.

Therefore, RTK is not about carrier wave phase. Static GPS and PPK (Post-Processed Kinematic) as well as RTK all use carrier phase measurement. The description of the two signals and how they are used is reasonable, and the carrier phase method does result in measurements that are more precise. However, RTK is not about the measurement process, but about getting the corrector information in “real-time” via the radio or cell phone link from one or more base stations. That information needs to be cleaned up and the details about the carrier phase moved to a different topic. I do not know if the quantitative data is accurate or not.

RTK does not necessarily use a single base station, although that is common. The statement is even contradicted later in the article.

By definition, a Bench Mark is not a “known surveyed location”. A bench mark may in atypical examples have a known location (to some sort of survey accuracy), but most often it has only an elevation and a rough location consisting of a narrative description and maybe coordinates scaled from a quad map. The concept is correct as described, but not using a bench mark. http://en.wikipedia.org/wiki/Benchmark_(surveying) is even linked from the article and belies the statement.

“Virtual Reference Station” (or at least the abbreviated form “VRS”) is a registered trademark Trimble Navigation Limited ( http://www.trimble.com/vrs.shtml ), and should not be used here without so stating. Additionally, VRS is only one system for providing correctors in real time from a network of base stations. A more correct term would be “RTN” or “Real-Time Network”.

The terms Continuously Operating Reference Station and CORS have nothing to do with RTK either, although a CORS station could also be part of an RTN. CORS stations predate widespread use of RTK and refer to a GPS receiver in a (presumed) permanent location that logs data continuously for later use in post-processing. Just because a station has been designated by the National Geodetic Survey as a CORS station (or somebody else has applied the term to their station) does not imply that there are real-time correctors available from that station. http://www.ngs.noaa.gov/CORS/ — Preceding unsigned comment added by 167.131.0.194 (talk) 00:50, 19 January 2013 (UTC)

Membership costs

Mention if one must be a paying member to be able to decode broadcast signals. Or if in some countries it is an open public service. Mention if 4G/5G networks are also used. Jidanni (talk) 18:10, 20 September 2021 (UTC)