Question 1: How are latitude and longitude divided? Longitude:
The line connecting the north and south poles and intersecting perpendicularly with the latitude, also called the meridian. Meridians indicate the north-south direction; all meridians are semicircular and of equal length; two opposing meridians form a meridian loop; any meridian loop can bisect the earth into two hemispheres.
Lines of latitude:
On the globe, the circles that surround the globe in the east-west direction are called lines of latitude. All lines of latitude are parallel to each other and perpendicular to the lines of longitude, which indicate the east-west direction. The latitude coils vary in size, with the equator being the largest. The latitude coils gradually shrink from the equator to the poles, and then shrink to points at the north and south poles.
The origin of latitude and longitude lines
In 334 BC, Alexander crossed the sea and invaded the south, and then marched eastward. The geographer Neelchus who accompanied the army searched for information along the way and prepared to draw a "world map" ". He found that along the route of Alexander's Eastern Expedition, from west to east, the seasons and the length of daylight were very similar. So an important contribution was made - for the first time, a latitude line was drawn on the earth, which started from the Strait of Gibraltar, along the Taurus and Himalayas to the Pacific Ocean.
Later, Eratos, who had long been the director of the Library of Alexandria in ancient Egypt, calculated that the earth’s circumference was 46,250 kilometers. He drew a world map with 7 longitudes and 6 latitudes. .
In 120 AD, Claudius Ptolemy synthesized previous research results and believed that drawing maps should be based on fixed points with known longitude and latitude, and proposed the concept of drawing a network of longitude and latitude lines on the map. To this end, Ptolemy measured the longitude and latitude of important cities and observation points in the Mediterranean area, and wrote eight volumes of geography. It includes the latitude and longitude of 8,000 places. In order to draw the longitude and latitude lines on the earth on a flat surface, he tried to draw the longitude and latitude lines into a simple fan shape, thus drawing a famous "Ptolemaic map".
In the early 15th century, Henry the Navigator began to put the "Ptolemaic Map" into practice. However, after repeated inspections, it was discovered that this map was not practical. Some of Henry's captains said regretfully: "Although we admire the famous Ptolemy very much, we find that the facts are contrary to what he said."
To correctly determine longitude and latitude, the key is to have "standards" bell". Making accurate clocks to keep time at sea is obviously much more convenient and practical than relying on celestial bodies to keep time. Harrison, a clockmaker in Yorkshire, England, spent 42 years making five timepieces in a row, each one more accurate than the last. The fifth unit is only the size of a pocket watch and has an error of only 0.54 kilometers in measuring longitude. At the same time, a marine timepiece designed and manufactured by French clockmaker Pierre Leroy was also put into use. At this point, the problem of longitude determination at sea has finally been initially solved.
On a map containing a latitude and longitude network, longitude lines are represented by the capital English letter E, and latitude lines are represented by the capital letter N. The letters are followed by the specific longitude and latitude values ??of the locations.
Question 2: How to distinguish between longitude and latitude. Meridians are semicircles and equal lengths. Latitude lines are circles and not equal lengths. The equator is the longest
Longitude is divided into east longitude and west longitude, and latitude is divided into southern latitude and northern latitude
The horizontal line on the globe is latitude, and the vertical line is longitude
Question 3: How to distinguish latitude and longitude? Most coordinate data expressed in longitude and latitude consists of two sets of numbers. Generally speaking, the first set of numbers is the longitude, and the last set of numbers is the latitude.
Longitude generally ranges from 0° to 180°, divided into east longitude and west longitude. East longitude is represented by the prefix E (EAST) in the coordinates, and west longitude is represented by the prefix W (WEST) in the coordinates; latitude starts from 0 ° to 90°, divided into northern latitude and southern latitude. North latitude is represented by the prefix N (NOTH) in the coordinates, and southern latitude is represented by the prefix S (SOUTH) in the coordinates.
1. Prefix
Simply put, if there is a prefix, the longitude and latitude can be distinguished according to the prefix. If the prefix is ??E or W, it must be longitude, and if the prefix is ??N or S, it must be longitude. Is the latitude (for example, E 78°36′43″, N 43°56′32″ means 78°36′43″ east longitude and 43°56′32″ north latitude);
2. If there is no prefix
It is divided into the following situations:
The first thing to declare is that if there is no prefix, you must know which hemisphere the coordinates are located, or the approximate location, such as the west of the northern hemisphere, Or the eastern part of the southern hemisphere. Otherwise, the data will have four groups and cannot be judged!
After figuring it out, read on:
1) If there is a set of numbers exceeding 90°, then this set of numbers must be longitude (because the latitude cannot exceed 90°). For example
113°36′43″, 43°56′32″, the first one is the longitude.
2) If both sets of numbers exceed 90°, you must know the approximate location of the coordinates on the map. You can first look at the approximate location of the integer longitude and latitude on the map, such as: the known coordinates are 48° 36′43″, 43°56′32″. You can first look at where E48°30′00″ and N43°30′00″ are. If they are closer to this coordinate, the front must be longitude, otherwise it is vice versa.
3) The two sets of coordinates are too close, such as: 48°36′43″, 48°1332″. Then ask the guy who gave you the coordinates. Who are you fooling if he doesn’t tell you the longitude and latitude?
4) The two sets of coordinates are the same. There is no need to explain this. It seems that the one is longitude and the other is latitude does not make much sense.
Third, there is another extreme situation.
Just give a set of numbers to know where the coordinates are. Please refer to method 2 without prefix! If there is no prefix or an approximate location, go find the person who gave you the coordinates and beat him! ! !
I typed for a long time, (I accidentally deleted it once when I was almost finished;_ Question 4: How to distinguish the longitude and latitude of the Northern Hemisphere: the further north (North Pole direction) the higher the latitude, and the closer to the equator the lower the latitude.
Southern Hemisphere: The farther south (in the direction of the North Pole) the higher the latitude, and the closer to the equator the lower the latitude.
Question 5: How to identify the longitude and latitude lines of fabrics:
Selvage: It is a narrow and tightly woven edge along the longitudinal edge of the fabric. Do not use it. It must be cut off.
Warp texture: It is parallel to the edge of the fabric. When cutting the length of the fabric, it is very important that the horizontal edge (cutting edge) across the width of the fabric is straight.
Twill: Yes. A diagonal line to the warp and weft texture rubber. In order to find the positive twill, measure the equal lengths on the selvage edge and the weft edge. However, you must first make sure that the weft edge and selvage edge are aligned. Right angle. Then use drawing powder and a meter ruler to mark the length of the measured size, and connect the two points with a straight line. This line marks the forward twill
Weft grain: It runs at right angles to the edge of the cloth. The direction of the warp and weft lines of each piece of fabric is different. Pay attention to it when cutting, otherwise the finished product will not have a sagging feel.
When cutting the fabric, place your left hand lightly on the cloth. Cut along the left side of the pattern or drawing: Hold the scissors in your right hand so that the pattern or drawing line is on the right side of the scissors.
Cut in the same direction. The length of the fabric. Some fabrics have a very obvious design direction, as if the edge of the fabric actually has the word "top edge" printed on it. For other fabrics, even plain weaves, have to look carefully as the fabric may have a sheen that affects the appearance. , this luster makes them produce different effects in different lights.
Question 6: Who can tell me how to distinguish the warp and weft direction of fabrics? (1) If the fabric to be identified has a selvedge, the direction of the yarn parallel to the selvage is the warp direction, and the other direction is the weft direction.
(2) The sizing is in the direction of the warp yarn, and the sizing is in the direction of the weft yarn.
(3) Generally, the denser fabric is in the warp direction, and the smaller fabric density is in the weft direction.
(4) For fabrics with obvious reed marks, the direction of the reed marks is the warp direction.
(5) For half-thread fabrics, usually the strand direction is the warp direction and the single yarn direction is the weft direction.
(6) If the yarns of single yarn fabrics are twisted at different times, the Z twist direction is the warp direction and the S twist direction is the weft direction.
(7) If the warp and weft yarn characteristics, twist direction, and twist degree of the fabric are not very different, the yarn will be uniform and shiny in the warp direction.
(8) If the yarn twists of the fabric are different, the twists will mostly be in the warp direction and the twists in the weft direction will be small.
(9) For towel fabrics, the direction of the terry yarn is the warp direction, and the terry-free yarn direction is the weft direction.
(10) Strip fabric, the strip direction is usually in the warp direction.
(11) If the fabric has a system of yarns with multiple different characteristics, this direction is the warp direction.
(12) For leno fabrics, the direction of the twisted yarn is the warp direction, and the direction of the untwisted yarn is the weft direction.
(13) In interwoven fabrics of different raw materials, generally cotton and wool or cotton and linen interwoven fabrics, cotton is the warp yarn; in wool and silk interwoven fabrics, silk is the warp yarn; in wool, silk and cotton interwoven fabrics, silk , cotton is the warp yarn; in the interweaving of natural silk and spun silk, the natural thread is the warp yarn; in the interweaving of natural silk and artificial silk, the natural silk is the warp yarn. Since fabrics have a wide range of uses and varieties, and the requirements for fabric raw materials and organizational structures are also diverse, the judgment must be based on the specific conditions of the fabric.