What is a UTM Grid Scale Factor

[@TalibHussainAttari]

appreciate sir thank a lot for sharing your knowledge

[@intannooraifatika8031]

Thank you for sharing sir!

[@Diva0205]

Tq u so much for ur videos... I watch ur videos regularly..... U explained well the difference between magnetic declination and convergency...I want to know that.... Why the convergency is varied from one position to another position......

[@JAOM]

Hi Convergence is varied due to varying curvature of earth. It actually depends on Latitude and not Longitude. More North or south you go, you will get more deference between True North and Grid North. I think I have explained that in that video. If not then I must have missed it.

[@Diva0205]

@@JAOM tq u so much sir...

[@Alex-di9wh]

Why in the formula the "easting coordinate of the given location in meters" is 500,000 ?? what type of convertion is? is there a formula?

[@JAOM]

Hi, the formula is given in the description. 500,000 is an assumed number representing the central meridian. You go east of central meridian by 100m, the number will be 500,100. You go 100m to the west of central meridian, the number will decrease to 499,900m. I have a very detailed explanatory video on Easting Northing and Central Meridian in my channel, if you are willing to see. Thanks for visiting.

[@MustafaKamilKASA]

Hi, I have some information about this subjec, but I didn't see before real life. Now ,I have same problem and I don't know exactly what to do on the site. I have cad file and benchmarks but all of them "UTM WGS84 6 degree" (by GPS) , I have total station. How can I use total station this project at site (for design setting out or surveying)

[@JAOM]

Hi, if I understand this correctly, your CAD files and Benchmark have coordinates in WGS 84 and UTM. That means you have easting and Northing in meters. You can directly use the UTM coordinates in Total Station. Depending on what you are measuring and what is the distance, you can take a decision on that. You can find the scale factor as stated in this video and apply that in your distance measurement. One thing I did not understand what is 6 degrees? Where do you see 6 degrees? Is that Latitude? And if you only have Latitude and Longitude in WGS 84, then you should convert them in Easting and Northing using a survey coordinate convertor. At the end of the day there are many factors that can affect your TS measurement. If all your measurement are on wgs84 ellipsoid then you dont have to worry about curvature calc in station height because all will be from ellipsoid. If you are using Local Grid then you need curvature correction and scale factor correction. I am not sure if I am able to answer you properly. Any measurement on actual topo surface is complicated and thats why we have geodesy and scale factor.... do let me know uf your problem is solved or I have complicated things.

[@MustafaKamilKASA]

@@JAOM Thank you for your interest. Please forget about 6 degrees, it's my fault. (That's what we learned when we were students) All measurements ,data and CAD file UTM WGS84 In this case, is it enough to just enter the scale factor into the total station? (for setting out and surveying from CAD file datas)

[@JAOM]

Yes you can enter point scale factor in TS.

[@richardwilmarsalascaballer8746]

excelente video, le agradeceria si sube o recomienda algun libro relacionado con el titulo del video para poder estudiarlo. saludos

[@JAOM]

Muchas gracias. Yo aprecio. No estoy seguro de ningún libro de este tipo, pero puede buscar en Google Scale Factor. Este sitio puede ayudar www.drillingformulas.com/scale-factor-in-utm-mapping-system-and-its-application-in-direccional-drilling/ Quizás tengas que traducirlo al español. 🙏

[@richardwilmarsalascaballer8746]

@@JAOM interesante esa direccion sobre factor de escala, ud quizas pueda sugerir algun libro en pdf que nos hable de conversion de coordenadas UTM a coordenadas TOPOGRAFICAS, calculando factor de escala, factor de elevacion, factor combinado, convergencia, etc. a la espera de sus comentarios. saludos desde PERU.

[@JAOM]

@@richardwilmarsalascaballer8746 Hola, para ser sincero, no estoy seguro de ningún libro de este tipo. He estudiado (Admiralty Manual of Hydrographic Surveying Vol 1 and Vol 2) "Manual del Almirantazgo de Levantamientos Hidrográficos" en la Armada. Pero estos libros no están disponibles en el mercado. Para coordenadas UTM, coordenadas cartesianas, tengo muchos videos en mi canal que puedes consultar. Hoy en día, existen cientos de programas distintos que se encargan de la conversión. Agradezco sus comentarios, pero no puedo ser de mucha ayuda con ningún libro.

[@rory_scott]

Why was a scale factor applied like this in the first place? I would have though that after the map was projected, it would be '1.000' down the middle of the zone on the central meridian, and something like 0.9996 on the edges? Why aim for having '1.000' at the very edges of the zone?

[@JAOM]

You have a very valid question. I tried to lookup your query but could not find anything that would satisfy me. I will keep looking. I thank you for this question. It gives me something to look for that I dont know.

[@rory_scott]

@@JAOM I have only just studied scale factors in one example and it seemed the reason was because the outcome of a transverse Mercator projection is that it’s accurate down the central meridian, but loses accuracy towards the east/west. I studied the local maps I use and it seemed like a scale factor was applied to the map such that the vertical lines of ‘1.000’ were evenly spaced out half way east and west across the coordinate systems, leaving the small error areas down the central meridian, and east/west edges.. but less distortion overall (I think) compared to the example in your video.

[@JAOM]

@rory_scott thanks, let me get back to you after I do some study. I have the resources at my work but presently I am on holiday.. Thanks again.

[@intannooraifatika8031]

In tranverse mercator map projection there are two types of mapping surfaces which are tangent and secant (video mention here). The question you raise here is for tangent mapping surface where the ellipsoid surface and grid surface is intersecting at the central meridian hence the scale factor at the central meridian is 1. Tangent mapping surface is being used for small extend area :)

[@Ombilistanga]

The answer to that is: The curvature touches the grid (the flat plane) on the edges (edges of the zone) hence scale factor 1 (that is where everything comes together and with zero separation) and, on the central meridian you have the maximum distortion (separation of the curvature from the flat grid, hence a large factor needs to be applied along the CM.

[@RUBYKINGSLY]

Sir , thank you so much , sir is there any simple formulas to convert lat lon coordinate to wgs 84 cartesian E , N coordinates .

[@JAOM]

Yes there is. SHould be open source to find in google or in chatgpt. Try it in google. Not simple though :)

[@RUBYKINGSLY]

@@JAOM ok sir thank you

[@JAOM]

To convert latitude, longitude, and height coordinates to Cartesian coordinates, you can use the following formula: It will better if you do the calculation in Microsoft Excel (but convert the Lat Long Degrees into Radians - google it) x = (N + h) * cos(lat) * cos(lon) y = (N + h) * cos(lat) * sin(lon) z = (N*(1 - e^2) + h) * sin(lat) where: x, y, and z are the Cartesian coordinates of the point in meters lat and lon are the latitude and longitude of the point in radians h is the height of the point above the reference ellipsoid in meters N is the radius of curvature in the prime vertical, defined as: N = a / sqrt(1 - e^2*sin^2(lat)) where a is the semi-major axis of the reference ellipsoid, and e is the eccentricity of the ellipsoid

[@RUBYKINGSLY]

@JAOM thank you sir let me work out this

[@laughinggood]

The easiest way is to use the convertion tool in Arc gis. Try it out it should work.

[@laxmansharma3796]

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