in the formula of calculating the experimetal variogram and the fitted model you need to. from math import atan, cos, radians, sin, tan from haversine_distance import haversine_distance def lamberts_ellipsoidal_distance( lat1: float, lon1: float, lat2: float, lon2: float ) -> float: """ Calculate the shortest distance along the surface of an ellipsoid between two points on the surface of earth given longitudes and latitudes. !pip install haversine. The haversine formula is an old equation used by navigators before the invention of modern-day navigation systems. Following is the code for a C function, haversine(), which computes the great-circle distance of two points on earth (or another sphere), using the Haversine formula. Hàm ShowLocation () giúp tính toán khoảng cách giữa 2 điểm và trả về cho người dùng. hav (Θ)는 하버사인 함수로 다음과 같이. The problem is I'm finding it hard to implement the Haversine Formula on the Arduino IDE, I'm relatively beginner on Arduino. Resolvendo d aplicando o haverseno inverso ou usando a função seno inversa, obtemos: ou. Java code to calculate the distance between two points using Haversine formula: public double getDistance (double startLat, double. Ch. Here's the code for this part. -. Once I remove the absolute value, the code works fine. Use the haversine distance formula to find the distance. 半正矢公式. Cite. MySql spatial data query for finding near locations using haversine formula. I share this background because it helps frame the Haversine formula’s key benefit: It provides a much more accurate distance "as the crow flies" over long. the code kindly suggested by blah238. Please note: The following script does not account for the curvature of the earth. Implement a great-circle. This is accomplished using the Haversine formula. 371 km), d é a distância entre dois pontos , é a latitude dos dois pontos e é a longitude dos dois pontos, respectivamente. Where; R = Radius of the Earth. Law of Haversine: To derive law of Haversine one needs to start the calculation with spherical law of cosine i. We would like to show you a description here but the site won’t allow us. Haversine Formula: As per wikipedia,The haversine formula determines the great-circle distance between two points on a sphere given their longitudes and latitudes. The haversine formula 1 ‘remains particularly well-conditioned for numerical computation even at small distances’ – unlike calculations based on the spherical law of cosines. Related. UPDATE Clarification in response to OP's comment:. The Haversine Formula is one result of such manipulations. The function takes two coordinates as input, each consisting of latitude and longitude values. 1. Include the <math. read_csv (filename) def haversine_wrapper (row): # return None when. I use this formula: φ2 = asin ( sin φ1 ⋅ cos δ + cos φ1 ⋅ sin δ ⋅ cos θ ) λ2 = λ1 + atan2 ( sin θ ⋅ sin δ ⋅ cos φ1, cos δ − sin φ1 ⋅ sin φ2 ) where φ is latitude, λ is longitude, θ is the bearing (clockwise from north), δ is the angular distance d/R; d being the distance travelled, R the earth’s radius. I am doing a silverlight bing map application. PI; However, atan2 let's the angle increase in CCW direction. MySql spatial data query for finding near locations using haversine formula. To associate your repository with the haversine-formula topic, visit your repo's landing page and select "manage topics. haversine_lib = ctypes. Combine already present Geo coordinates with the new ones. It gives the shortest distance between the two yellow points. The formula for distance between two point (x1, y1) and (x2, y2) is. SELECT v. Sin (dlat), 2) +. 1. The expression under the radical, that you call a in your question, equals roughly 0. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. Net instead, since I code in C++(no . atan2 is a common function found in almost all. Haversine formula isn't bad. Geolocation. The second is that the ArcGIS Map will only display 1,000 points without upgrading to Plus. 0. The Jaro similarity between strings and is defined using the formula: Where: is the number of matching characters. The formula is rather straightforward as the distance is calculated from the cartesian coordinates of the points using the Pythagorean theorem. It's analogous to calling the function for finding the distance between two Cartesian coordinates Pythagorean instead of Distance. We indebted to the formulas written here. The calculation can be done by computer, or by hand via tabular methods and longhand methods. There are numerous documents Convert lat/long to XY explaining this problem. The Haversine formula accounts for the curvature of the earth, but assumes a spherical earth rather than an ellipsoid. You can read more about the benefits and limitations of the haversine formula and a discussion of other formulas here. Copyright © 2000–2022, Robert Sedgewick and Kevin Wayne. 141592653589793; const double RADIO =. Apply Haversine Formula to Calculate Distance Between Two Cities. 887 1 1 gold badge 9 9 silver badges 18 18 bronze badges $endgroup$ 13. A simple haversine formula module for Node. 5:1-5 John is weeping much because only Jesus is worthy to open the book. Tap into an extensive set of aviation data, including real-time flight status, historical flights, schedules, airline routes, airports, aircrafts, and more. MySql Latitude and Longitude. 3. If the length of the three sides is (from u to v), b (from u to w), and c (from v to w), and the angle of opposite view c is C, so that the law of haversines consists of three, as follow: haversine(c)=haversine(a−b) sin(a)sin(b)haversine(C) (1) The Haversine formula serves to find the distance between the user's location and the destination Add a comment. The function takes two coordinates as input, each consisting of latitude and longitude values. I can't use math methods in Java-1. The dotted yellow line is an arc of a great circle. When the two points are antipodal (on opposite sides of the Earth), the Haversine Formula is ill-conditioned (see the discussion below the Law of Cosines for Spherical Trigonometry), but the error, perhaps C++ implementation of the Haversine formula. sql-server × 9. The intermediate result c is the great circle distance in radians. Problem can be solved using Haversine formula: The great circle distance or the orthodromic distance is the shortest distance between two points on a sphere (or the surface of Earth). It is a special case of a more general formula in spherical trigonometry, the law of haversines, relating the sides and angles of spherical "triangles". sin (), math. from. I'm trying to use the Haversine formula for this. 하버사인 공식 (Haversine Formula) 이런 경우 두 위경도 좌표 사이의 거리를 구할 때 사용하는 것이 하버사인 공식입니다. Spherical Trigonometry. hava = 1 − cosa 2 = sin2a 2. Generated by CODECOGS. Haversine in C#: Calculate the distance between two points along the surface of a sphere. If you master this technique, you can tackle any required distance and bearing calculation. Currently explicitly supports both cardinal (north, east, south, west) and intercardinal (northeast, southeast, southwest, northwest) directions. Important in navigation, it is a special case of a more general formula in spherical trigonometry, the law of haversines, that relates the sides and angles of spherical. I was just hoping come up with something that would work for. Remember minutes and seconds are out of 60 so S31 30' is -31. Where: s is the geodesic distance along the surface of the ellipsoid (in the same units as a & b); α 1 is the initial bearing, or forward azimuth; α 2 is the final bearing (in direction p 1 →p 2); Note: Vincenty observes that eqn. 4305/W (Kahului Airport), where the LA Airport is the starting. The first table of haversines in English was. 90210) and either the central point of the zip code or the entire area covered by the zip code in another column (or both if that makes sense for your application). Calculates a point from a given vector (distance and direction) and start point. 8987/N 156. You signed out in another tab or window. Select the units in which you want to measure the distance between. λ1, λ2: 1지점과 2지점의 경도 (라디안 단위). To match that in ArcGIS, you'd have to have the data's CRS use the same sphere model. GPS - Is the haversine formula accurate for distance between two nearby gps points? 3. Calculating distance with latitudes and longitudes. The Haversine formula gives the "as-the-crow-flies" distance, i. import math def get_distance (lat_1, lng_1, lat_2, lng_2): d_lat = lat_2 - lat_1 d_lng = lng_2 - lng_1 temp = ( math. e. When used for points on the Earth, the calculated distance is approximate as the formula assumes the Earth to be a perfect sphere. In order to obtain the haversine formula of the previous section from this law, one simply considers the special case where u is the north pole, while v and w are the two points whose separation d is to be determined. pairwise() accepts a 2D matrix in the form of [latitude,longitude] in radians and computes the distance matrix as output in radians too. 1. Important in navigation, it is a special case of a more general formula in spherical trigonometry, the law of haversines, that relates the sides and angles of spherical triangles. Better still if you want to say find a list of stores within a certain radius, you could apply a WHERE clause in SQL or a LINQ filter in C# to it. Now, the angular lengths of the sides of the triangle (in radians) are then , , and , and the actual arc lengths. This seemed like an excellent opportunity to create a. 5) before running more resource intensive. /** * Calculate the distance between two points in meters using the Haversine formula * * @param lat latitude of the first point * @param lon longitude of the first point * @param lat2 latitude of the second point * @param lon2 longitude of the second point * @return the distance between the two points in meters **/ public static double. Implement a great-circle. 0 / Math. 2. I followed the entire formula so I don't really know where the math/code problem is. The Haversine (or great circle) distance is the angular distance between two points on the surface of a sphere. 5k. I am trying to implement Haversine formula into excel function. The Haversine Formula is defined like this: Haversine Formula. All of the Haversine formulas use a sphere. The ‘(re)versed sine’ is 1−cosθ, and the ‘half-versed-sine’. The problems of k-means are easy to see when you consider points close to the +-180 degrees wrap-around. 1 1. Trong toán học, khoảng cách Euclid ( tiếng Anh: Euclidean distance) giữa hai điểm trong không gian Euclid là độ dài của đoạn thẳng nối hai điểm đó. Versions Compatible and additional computed target framework versions. The haversine formula. . It gives the shortest distance between the two. Then enter the latitude and longitude of your destination point in cells A2 and B2, also in degrees. Reload to refresh your session. ; Cosine Similarity: It measures the angular cosine similarity between 2 vectors. Method 1: Without using the inbuilt. The formula is given below. For example, the Cartesian formula for distance (Pythagoras) involves one call to sqrt(). The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. R = 3960. Here is the example result delivered by Haversine Formula: Lets take one of latitude-longitude for calculation distance, NEBRASKA, USA (Latitude : 41. Here my code I used below code to calculate the distance between two location using their latitude and longitude. You switched accounts on another tab or window. Taken from the codecodex. We can then apply the SortByColumns function around the return value of AddColumns to return the records sorted by distance ascending order. FORMULA: haversine (d/r) = haversine (Φ2 – Φ1) + cos (Φ1)cos (Φ2)haversine (λ2 -λ1) Where d is the distance between two points with longitude and latitude ( λ,Φ ) and r is the radius of the earth. Your formula is almost correct, but you have to swap parameters for longitude an latitude. Here Δφ = 1. Microsoft uses the ellipsoid Earth to calculate distances instead of a sphere providing more accurate. West and South locations are negative. The haversine formula calculates the shortest distance between two points, whose latitudes and longitudes are known, in a sphere. The ‘(re)versed sine’ is 1−cosθ, and the ‘half-versed-sine’. What is the Haversine formula for finding the distance. The distance using the curvature of the Earth is incorporated in the Haversine formula, which uses trigonometry to allow for the Earth’s curvature. The location can be input in two different formats, as latitude and longitude in a character string, e. Implement a great-circle. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. This will avoid any round-Step 1: Installing “haversine” To install haversine type following command in jupyter notebook. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. To do this I needed to convert my lat/lng co-ordinates into radians. The ‘(re)versed sine’ is 1−cosθ , and the ‘half-versed-sine’ is (1−cosθ)/2 or sin²(θ/2) as used above. The Haversine formula is used to calculate the distance. lat1 = lat1 * PI/180 Convert the starting point longitude 'lon1' (in the range -180 to 180) to radians. The Haversine formula accounts for the curvature of the earth, but assumes a spherical earth rather than an ellipsoid. Resolviendo d aplicando el haversine inverso o usando la función seno inversa, obtenemos:Package haversine is a Go library which implements the haversine formula. outcode = 'CB6' ORDER BY distance. To develop this formula it is necessary to recall the following four funda-This is where we can rely on a mathematical function called a haversine. 0. It has many practical applications, including finding the. Esta fórmula toma en cuenta la curvatura de la Tierra para obtener un resultado más preciso. HAVERSINE¶ Calculates the great circle distance in kilometers between two points on the Earth’s surface, using the Haversine formula. Ellipsoidal models: Most accurate at any lat/lon and distance, but is still a numerical approximation that depend on what accuracy you need. haversine_lib = ctypes. It is a special case of a more general formula in spherical trigonometry, the law of haversines, relating the sides and angles of spherical "triangles". We used the Google Maps. The straightforward formula with arccosine has poor accuracy when the angle is small (the most common case), due to the fact that cosine is flat at $0$. Sorted by: 5. The following query would return documents from the places collection within the circle described by. The general formula for calculating the angle (bearing) between two points is as follows: θ = atan2 (sin (Δlong)*cos (lat2), cos (lat1)*sin (lat2) − sin (lat1)*cos (lat2)*cos (Δlong)) Note that the angle (θ) should be converted to radians before using this formula and Δlong = long2 - long1. Here's a refactored function based on 3 of the other answers! Please note that the coords arguments are [longitude, latitude]. Maintainer: Ramesh Saud. . θ = Angle introduced at the center of the Earth by the two addresses. between the two points on the longitude and latitude [13]. The Haversine calculator computes the distance between two points on a spherical model of the Earth along a great circle arc. Last updated: Thu Aug 11 10:12:06 EDT 2022. It's a basic Haversine function, using the code below: private static double Haversine (double lat1, double lat2, double lon1, double lon2) { const double r = 6371e3; // meters var dlat = (lat2 - lat1)/2; var dlon = (lon2 - lon1)/2; var q = Math. 0 or above 1. Task. The Haversine formula is a mathematical formula that gives the distance between two points on the surface of a sphere. atan2 (√a, √ (1−a)) d = R. 1 Answer. Outer join to city Geo coordinates with city cluster coordinates to get all possible combinations. Calculating shortest path between 2 points on a flat map of the Earth. Assuming that you want to compute haversine () with the first element in each user id group against all the other entries in a group, this approach will work: # copying example data from OP import pandas as pd df = pd. Using the Haversine formula with PostgreSQL and PDO. e. d = 2r * arcsin (sqrt (sin² ( (lat2-lat1)/2) + cos (lat1) * cos (lat2) * sin² ( (lon2. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. The equatorial radius of the Earth is approximately 3,963. On my site I'm trying to get locations nearby. The problem I'm having is when using the test values given by the instructor I get a greater answer than what he gets. 3. h> file into my C file so that I get pi. The formula here is in kilometres, you will have to change the relevant numbers and it. import numpy as np def Haversine(lat1,lon1,lat2,lon2, **kwarg): """ This uses the ‘haversine’ formula to calculate the great-circle distance between two points – that is, the shortest distance over the earth’s surface – giving an ‘as-the-crow-flies’ distance between the points (ignoring any hills they fly over, of course!). Task. It is the shortest distance between two points on the surface of a sphere, measured along the surface of the sphere (as opposed to a straight line through the sphere's interior). I was recently using Google Maps API geo-location lookups to get the longitude and latitude of an address entered by the user. sin²(ΔlonDifference/2) c = 2. I am trying to find the distance between two longitude and latitude points. Task. We can immediately observe some relationships between , and the angle (measured in radians) that the great circle arc makes with the centre of the sphere: we have. . Also, this example demonstrates applying the technique from that tutorial to. The vectors from the center of the sphere to the vertices are therefore given by , , and . 2. g. Question/Requirement. W. Code. function haversineDistance (coords1, coords2, isMiles) { function toRad (x) { return x * Math. However, you can use it to calculate distances on land as well. GeoCoordinate)' method, and this method cannot be translated. I'm calculating the distance between 33. Here, there are about 111,300 meters in a degree. S = Distance between two addresses. 137, //radius of the earth in kilometer pi = Math. It uses the Haversine formula to calculate the distance based upon the supplied GPS coordinates. Vincenty's formulae are two related iterative methods used in geodesy to calculate the distance between two points on the surface of a spheroid, developed by Thaddeus Vincenty (1975a). lng, p. Accuracy is within 0. atan2 (). 1. d = 2Rarcsin√sin2Δφ 2 + cosφ1cosφ2sin2Δλ 2. I am trying ot use the great circle distance. I want to implement the Haversine Formula to find the distance between two points, in order to compute it with the radius. getPlacesNear (latitude,longitude,distance); } and the endpoint: @GetMapping ("/location") public. Aug 31, 2012 at 22:41. You can cluster spatial latitude-longitude data with scikit-learn's DBSCAN without precomputing a distance matrix. We will use the distance formula derived from Pythagorean theorem. Haver sine formu la is commonly. It is giving wrong distance. As always, the code used in the examples is available over on GitHub. Now simply apply the following formula, where φ stands for latitude and λ longitude. Our free online distance finder also uses the same formula to calculate the distance between places up to most accuracy. Then the haversine formula calculates the distance between the two places. Haversine in C#: Calculate the distance between two points along the surface of a sphere. sin² (Δλ/2) c = 2. Device. Spherical Trigonometry. The Haversine Formula is more accurate than the law of cosines formula because of problems associated with small distances. To calculate, we will first load our data into Matlab, add the data path, and then load the data as shown below: %% load data acquired by position data %load position data addpath('/MATLAB Drive/MobileSensorData') load sensorlog. Finalmente, a função haversine hav (Θ), aplicada acima para ambos o ângulo central Θ e a diferenças. You will need to choose whether you want miles or kilometers. The Haversine formula is nice and fast, but it has a ‘fatal’ flaw of returning NULL sometimes when measuring the distance between a point and itself. Calculate the distance between two coordinates by latitude and longitude, including a Javascript implementation. Latitude)) <= radius); And got: LINQ to Entities does not recognize the method 'Double GetDistanceTo (System. Multilanguage (C#/Matlab/Rust) library for solving navigation (2D/3D) & geodetic problems: Multilateration (true range), Time-Of-Arrival (TOA), Time-Difference-Of-Arrival (TDOA), Angle-Of-Arrival AOA (Direction-Of-Arrival, DOA); Direct & inverse geodetic problems: Vincenty equations, Haversine formula; Virtual Long Baseline navigation. g. This post described a how to perform this calculation in Power Apps in both kilometers and miles, including a verification of the result. It takes into account the curvature of the Earth’s surface and. It is a special case of a more general formula in spherical trigonometry, the law of haversines, relating the sides and angles of spherical "triangles". The discussion below gives a second version of the haversine formula thatThe Wikipedia article probably does a better job of explaining how the formula works than me, and there's also this aviation formulary page that covers that goes into more detail. This is the distance in a straight line, if you need the distance on a path you will have to find all points on that path and then calculate the distances between each two points and then take the sum of that. In order to use this method, we need to have the co-ordinates of point A and point B. Is there a better formula to get the exact middlepoint ON THE TRACK? – Dirk. Remember. The haversine formula [no capital, haversine = "halve versed sine" is not the name of a person] calculates the distance between longitude/latitude points assuming a spherical earth. To compute the distance between two points, use the Haversine formula. Now for the C code! To convert this code, there were three things I had to do to implement this as C code: A. lat, v. It is a special case of a more general formula in spherical trigonometry, the law of haversines, relating the sides and angles of spherical "triangles". navigation geolocation haversine nelder-mead positioning trilateration time-of-flight haversine-formula tof multilateration toa aoa tdoa hooke-jeeves time-of-arrival vincenty-formula angle-of-arrival vincenty-inverse. Longitude, x. That being said, if the points are close together, the results should. Code Issues Pull requests Discussions ZSWatch - the Open Source Zephyr™ based Smartwatch, including both HW and FW. The algorithm used in this study uses the haversine formula which will later help to find the nearest boarding house location around the campus of Mulawarman University, the haversine formula will. 5. Reload to refresh your session. 4081/W (LA Airport) and 20. You’ll notice I mentioned Earth’s average radius above. Working with atan2. To calculate the distance between two points given longitude and latitude coordinates: Write down each point's coordinates in degrees-only format. . python spatial-analysis haversine latitude longitude spatial-data haversine-formula distance-calculation vincenty vincenty. Distance =. 507483, longitude : -99. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. The Haversine formula is more robust for the calculating the distance as with the spherical cosine formula. Implement a great-circle. C#; nathanrooy / spatial-analysis Star 16. The flat earth formula will be much faster than the haversine. {\displaystyle \operatorname {hav} (c)=\operatorname {hav} (a-b)+\sin(a)\sin(b. You signed in with another tab or window. The formula in this library works on the basis of a spherical earth, which is accurate enough for. Many languages have this function. 今回は緯度経度から2地点間の距離を求めます．GoogleのAPIやMathematicaなど様々な場所で2点間の距離を求める計算が行えますが，これらの計算を行うにあたって地球は回転楕円体なので正確に2地点間の距離を求めることが難しいです．そこで，この. If so, I recommend using the build-in geography data type rather than doing the Haversine calculation directly. Thus, from (4) and (7), 1 - 2 hav a = cos b cos c + sin b sin c (1. Here's a refactored function based on 3 of the other answers! Please note that the coords arguments are [longitude, latitude]. It's called the haversine and it's defined in terms of the sine function: The dotted yellow line is an arc of a great circle. Get nearest distance based on geolocation. SELECT LAT, LONG, ( 3959 * acos ( cos ( radians (37) ) * cos ( radians ( LAT ) ) * cos ( radians ( LONG ) - radians (-122) ) + sin ( radians (37) ) * sin ( radians ( LAT ) ) ) ) AS distance FROM Table ORDER BY distance. Performance Centres of Asia. Using the Haversine formula with PostgreSQL and PDO. The method takes four parameters: the latitude and longitude of. Using the Pythagorean formula on positions given in latitude and longitude makes as little sense as, say, computing the area of a circle using the formula for a square: although it. $egingroup$ At first I was thinking that it might be possible to scrape the Haversine formula and just compute the Euclidean distance between the two points -- I guess that would work for most cases since the data points have randomly generated altitudes between 0 and 1200 miles. For any two points on a sphere, the haversine of the central angle between them is. So I'm trying to use the haversine formula in Unity to get the distance between two different points (latitude and longitud given). 5mm (not metre, half a millimetre) instead of 0. For any two points on a sphere, the haversine of the central angle between them is given by: Where. 5% as it is assuming the earth is a sphere. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. Given a list of geographic coordinate pairs, you can implement the Haversine formula directly in Excel. The Haversine Formula is defined like this: Haversine Formula. 2. sin (d_lat / 2) ** 2 + math. The Haversine Formula in C# and SQL: Distance between two points Storm was recently asked to create a local office finder for a client. 它是 球面三角學 中“半正矢定理”公式的特例，该定理涉及了球面三角形的边和角。. The study was conducted by taking the location of drivers and Temporary Shelters in the form of coordinate points, calculating the distance. But if you have GPS coordinates of two. When you’re finding the distance between 2 places on Earth (as the crow flies), a straight line is actually an arc. 2 Answers. atan2 (). Euclidean Distance: It measures the straight line distance between 2 points in space. Below is my code (implementation of Haversine formula) float calcDistance (double latHome, double lonHome, double latDest, double lonDest) { double pi = 3. Task. c# Improve this page Add a description, image, and links to the haversine-formula topic page so that developers can more easily learn about it. so. Input them in the haversine distance formula: d = 2R × sin⁻¹ (√ [sin² ( (θ₂ - θ₁)/2) + cosθ₁ × cosθ₂ ×. The Haversine formula is used to find the distance between two geographical locations. GPS. Multilanguage (C#/Matlab/Rust) library for solving navigation (2D/3D) & geodetic problems: Multilateration (true range), Time-Of-Arrival (TOA), Time-Difference-Of-Arrival (TDOA), Angle-Of-Arrival AOA (Direction-Of-Arrival, DOA); Direct & inverse geodetic problems: Vincenty equations, Haversine formula; Virtual Long Baseline navigation. One can derive Haversine formula to calculate distance between two as: a = sin²(ΔlatDifference/2) + cos(lat1). To convert lon1,lat1 and lon2,lat2 from degrees. The equation of a line in the plane is given by the equation ax + by + c = 0, where a, b and c are real constants. –Inverse Haversine Formula. Haversine formula: The haversine formula can be used to find the distance between two points on a sphere given their latitude and longitude: In the haversine formula, d is the distance between two points along a great circle, r is the radius of the sphere, ϕ 1 and ϕ 2 are the latitudes of the two points, and λ 1 and λ. Calculating distance in kriging using Euclidean distance formula between two points on XY axes, and I found that not sufficient because I specified Lag_units and Lag_distance in meters when I programmed kriging. For some reason this only works in the northern hemisphere and I'm suspecting its because of the abs. The basic idea being at very small scales, the surface of a sphere looks very much like a plane. You're not going to be able to match it even by adjusting the sphere radius in a Haversine formula. The great circle method is chosen over other methods. Once I remove the absolute value, the code works fine. C# Return type that matches type passed to function in. 半正矢公式 是一种根据两点的 经度 和 纬度 来确定 大圆上两点之间距离 的计算方法，在 導航 有着重要地位。. the Earth) in the units system that you want to convert the distance to. It gives the shortest distance between the two yellow points. Learn more about TeamsIf you really need the Haversine formula, you might want to look into this discussion. 5707963; R = 3956; /* the radius gives you the measurement unit*/ a = HalfPi - latoriginrad; b = HalfPi - latdestrad; u = a * a + b * b; v = - 2 * a * b * cos(longdestrad - longoriginrad); c = sqrt(abs(u + v)); return R * c; The Haversine formula calculates the shortest distance between two points on a sphere using their latitudes and longitudes measured along the surface. a bit of background - This Linq-to-SQL makes up a WCF service which connects the database and aims approximately the 25 nearest 'stops' to the user. This is best library to calculate the azimuth angle between two gps cordinates.