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6

You should be able to do a simple 'select by expression' where DATECOLUMN like "% 12%" This is assuming your date is a string column. Essentially; the query is using the 'pattern' that is formed, and saying "Find me every record where there's a space, followed by 12, follow by a colon. Since your data is in 24h format, the only records criteria that ...


2

First of all, the GPS Almanac consists of information about the GPS constellation, satellites' health and their course in order to make it easier (possible) for your receiver to find them in the air. (Most of the time, you do not need to download that since you did before, but that is a discussion for another Q/A). The point is, almanac is not important for ...


2

If you set the project CRS in QGIS to EPSG:32718 (UTM zone 18), you get the same coordinates as reported by Google Earth. You might get different results if you have chosen another CRS. There are several CRS that are called UTM 18S (=South), but only one is based on the WGS84 ellipsoid. The negative Y coordinate looks like a UTM 18N (=North) CRS. For QGIS, ...


2

A common entry-level GPS has an absolute precision of roughly 40 feets, but there are many "tricks" that help improving this precision. For instance, you can collect several points of the same position and average this position (which is not a good solution if I understand well your case) or you can use WAAS enabled GPS. I see that you live in the States, so ...


1

My favorite app for doing these kinds of things is Locus map free. It can import KML file amongst many other formats, and can work completely offline. If you need a base map, you can either download it within the app (for a fee) or add your own data either in mbtiles, or one of the other myriad formats that it supports.


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I have never tried them myself, but it looks like the iScreenDisplay interface has rotation functions: iScreenDisplay Also check out screenDisplay.DisplayTransformation.Rotation() Might be a good starting point.


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One example is if you are setting up an RTK survey, but don't have any permanent marks. In this situation, you set up a base station and observe for 6+ hours while you undertake your field work with a radio-connected rover (you might be able to do this disconnected?), then you can post-process to identify the coordinates of your base station. ...


1

First, RTK stations are not always available. There are some countries where there are no or little stations, and according to this source even in the US you have states without public RTK. So you then need your own base station and if you want to make you own RTK you need an emitter in addition to the GPS receiver, so this i more expensive. EDIT: for the ...



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