best map projection for california


You can't squash a grapefruit peel flat without breaking it into many pieces (try it sometime). Cylindrical projections are the only one of the three main types that can show the entire globe, and so most world maps are cylindrical. It's somewhat flattened at the Poles, so an ellipsoid represents Earth better (an ellipsoid is formed by rotating an ellipse around one of its axes). It would be 4,203,600 meters, or 4,203.6 km, north of the Equator. How can you determine coordinates more precisely? (accuracy: 4.0) Area of use: United States (USA) - California - counties Imperial; Orange; Riverside; San Diego. (accuracy: 1.0) Our survey system no doubt contributed to the ideal of American individualism. For these reasons, lat/long is usually replaced by other coordinate systems, especially at the local level, for most descriptions of location. Choosing projected coordinate system for mapping all US states? Instead, they simply have equations that tell where to plot each latitude/longitude coordinate from the globe. Often east-west correction lines were set up, along which townships were re-aligned. The US Public Land Survey, described below, became the US answer to the problem. Powered by EPSG database 9.8, EPSG:3310 The Mercator shows Greenland almost as large as South America, when in reality it is about 1/8 the continent's size. Getpositiononamap, EPSG:2230 Even today, land titles are more difficult to verify in areas surveyed by metes-&-bounds. Strange coordinates for San Francisco: 5979762, 2085921 from Shapefile, Choosing between several very similar projections, EPSG codes for projections to use when computing the area of global polygon sets in python env. In this case, the globe is projected onto a flat surface. Away from the tangent locations, the map surface gets further from the globe, and hence more distorted. Getpositiononamap, EPSG:2771 with transformation: 15931, EPSG:2875 It is used extensively in remote sensing, computerized mapping, and geographic information systems. The idea is very simple: a land parcel is described based on going from one point to another, in a polygon that encompasses the parcel. Actually, the diameter at the equator is only about 42.8 km more than the polar axis. If someone asks you, "where is Hawaii? Then we have two lines of tangency, or two standard parallels, along which the map is extremely accurate. But if you need a general--purpose map of the world or continental area, an equal--area map, or a map that is very close to equal--area, is your best bet. Area of use: United States (USA) - California. The third type of projection is made onto a cone. Within each UTM zone, x,y coordinates can be given in meters. Each zone used its very own projection and coordinate center and system. The best answers are voted up and rise to the top, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company. This puts the "false origin" off to the southwest. An important fact about survey systems is that once land is surveyed under a given system, that's it--the description of the land stays with it permanently. First, notice that meridians converge at the Poles. Usually tick marks on the margins of the map show regular spacing of the grid, and selected marks have the actual coordinates in feet. Most of the time, this worked alright, and in a sense it shapes human use of the land according to the landscape itself, rather than imposing an artificial pattern on the land.

They also lettered north--south segments of each zone from A (south) to Z (north). Alas, early map--makers didn't do this, exactly. To learn more, see our tips on writing great answers. Transformcoordinates | The township is also a certain number of Townships north or south of the baseline (note the dual use of the term township, as an area and as a coordinate). Transformcoordinates | Identifying coordinate system of San Francisco data? Phone: 510.746.7334 In Louisiana and other areas settled by the French, long-lots were used. Show that involves a character cloning his colleagues and making them into videogame characters? These rectangularly-surveyed areas look like PLS areas as you travel over them, even though officially they're not. with transformation: 1188 A degree of longitude decreases from about 111 km at the Equator to 0 at the Poles; 1 is about 88 km in Sonoma County. Much of the land was given or sold to large landowners for ranchos as Spanish Land Grants. The UTM grid is shown on all recent USGS topographic maps. A final problem with metes-&-bounds was that the US government wanted to sell off land in the West quickly, in order to raise cash (no income taxes back then). Transformcoordinates | This way, you can follow the straight segments on the Mercator map with a compass, and turn only when you need to follow the next segment. This two--line approach is also called the secant case, as opposed to the simple tangent case. This is simply a sheet of paper, plastic or other material that has finer distance intervals marked off that match the scale of the map. That's designed for large scale purposes. Since surveys were done as land was claimed, overlapping claims often resulted--with lengthy court battles ensuing. Townships are designated on the east-west direction as being a certain number of Ranges east or west of the principal meridian. Since all land is divided into squares, the landscape itself looks very square. Choosing map projections specifically for San Francisco Bay Area? But it is enough to throw off exacting measurements, like property lines. In the EPSG Geodetic Registry, they are 7131 and 7132. with transformation: 1188 The map surface onto which the projection is made can be various shapes, and can also be at various places. with transformation: 15931 Most land purchases were for less than one section; the Homestead Act of 1863 allowed people to receive one-quarter section if lived on by the claimant. This resulted in a series of long but narrow plots of land that are still evident on topo sheets of Louisiana, coastal Texas, and Mississippi River towns, even as far upstream as Wisconsin. Lat/long is cumbersome to use for at least two reasons. Within each zone, then, the grid is very accurate in matching true Earth distance and direction. Nearly all states have multiple zones, but zones never cross county lines. Most planar projections preserve true direction away from the center of the map (usually the Pole) and so azimuthal is nearly synonymous with planar projection. Unfortunately, it greatly distorts the sizes of areas near the Poles (see section 3 below), so it should not be used as a general--purpose world map! The UTM grid, even if drawn in on the map, may not give us the exact coordinates for a given location. (in 0.068738 seconds), EPSG:3310 Use the UTM or SPC grid instead. What drives the appeal and nostalgia of Margaret Thatcher within UK Conservative Party? Although we cannot use conic projections for a world map, they are excellent for continent--sized areas in the mid--latitudes. Most all projections nowadays are done by computer using equations that relate lat/long to x/y coordinates on the map. Not very far, but you'd have trouble giving me the distance even in terms of degrees/minutes/seconds. The land along important lanes of commerce, usually rivers, was divided into narrow strips extending back into the interior. The initial point is the intersection of the principal meridian and baseline. with transformation: 15930, EPSG:26946 For smaller scale mapping, use state plane, commonly referred to as "CCS" by California surveyors. Area of use: United States (USA) - California - counties Imperial; Orange; Riverside; San Diego. A square mile contains 640 acres, so a quarter section has 160 acres, a quarter-quarter 40 acres, and so on. with transformation: 15931, EPSG:2771

They wanted low numbers on both sides of the Prime Meridian (the 0 line). Surveying in wet or mountainous terrain is difficult, and lines often went astray. Remember, once surveyed, never again. 120 zones cover the US. Convergence makes lat/long poor for use as a rectangular grid, where we want simple x,y coordinates for locations. The UTM coordinates for SSU are: 4,243,540 m E, 528,390 m N (these are actually close to the coordinates for Stevenson 3065). There are many irregularities, which are especially noticeable in certain regions. The UTM has many zones, each with its own projection centered on a meridian.

UTM zones extend north--south, practically from Pole to Pole. Is there any criminal implication of falsifying documents demanded by a private party? In order to keep all SPC numbers positive, the origin for each zone is placed off to the southwest of the actual zone covered.

You may see maps of the US with a statement on the bottom like: "Lambert Conformal Conic Projection, 48 and 33 Standard Parallels." Any x,y coordinate system needs an origin, that is, where the coordinates are (0,0). Since gravity and Earth's surface are irregular, the geoid is not a smooth surface, and can't be represented with equations easily, so it's rarely used for mapping. I am asking because I am not familiar with specific map projections for the San Francisco Bay Area. How does a tailplane provide downforce if it has the same AoA as the main wing? http://epsg.io/4430 if you want survey feet.http://epsg.io/32610 if you want meters. As with the SPC system, going across zones is difficult, so the UTM is meant primarily for local and regional measurement.The UTM was adopted and thus popularized by the Army in 1947. Getpositiononamap, EPSG:26946 Conic projections are usually made more accurate by "sinking" the cone part way into the globe (remember, this is all done with computers, not literally!). Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. Press question mark to learn the rest of the keyboard shortcuts. The division was into 36 sections, one square mile each. A bigger problem is that the boundary markers (oak tree, big rock) eventually are obliterated, with the boundaries becoming ambiguous.