Comments on: C#, GPS Receivers, and Geocaching: Vincenty’s Formula http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/ Mike Gavaghan blogs on Java, C#, .Net, and the software industry Fri, 21 Nov 2008 00:34:22 +0000 http://wordpress.org/?v=2.1.3 By: Jay Allen http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-45 Jay Allen Wed, 22 Aug 2007 19:21:45 +0000 http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-45 Read this on CodeProject.com. Great stuff - and great blog! Read this on CodeProject.com. Great stuff - and great blog!

]]> By: Russ Lankenau http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-87 Russ Lankenau Tue, 04 Dec 2007 18:15:52 +0000 http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-87 Mike, Great post! I've been looking over the Vincenty paper trying to get a handle on this, and I found some FORTAN and C++ code on the web, but your post is explained much more clearly than anything else I've found. Mike,

Great post! I’ve been looking over the Vincenty paper trying to get a handle on this, and I found some FORTAN and C++ code on the web, but your post is explained much more clearly than anything else I’ve found.

]]> By: Klaus Lenssen http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-98 Klaus Lenssen Sat, 05 Jan 2008 12:07:35 +0000 http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-98 Mike, excellent work - I am new to geodesy and I found your C# class very handy to write an small application to analyse the tracks I recorded with my new GPS mouse. Next thing is write a class to create kml files. Mike,

excellent work - I am new to geodesy and I found your C# class very handy to write an small application to analyse the tracks I recorded with my new GPS mouse. Next thing is write a class to create kml files.

]]> By: Binaryjam http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-101 Binaryjam Fri, 01 Feb 2008 10:10:22 +0000 http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-101 Mike, you are an absolute star ! I'm absolutely terrible at maths like this and your easy to use library enabled me to calculate all the adjacent postcodes in the UK for each other. Using this library I can improve the legacy car sharing app I wrote to accurately find other car sharers by bounding box filter and distance calculations. This is undoubtedly the best bit of C# code/ Complete library I have ever come across. Thankyou Soooo much !!!! Mike, you are an absolute star ! I’m absolutely terrible at maths like this and your easy to use library enabled me to calculate all the adjacent postcodes in the UK for each other.

Using this library I can improve the legacy car sharing app I wrote to accurately find other car sharers by bounding box filter and distance calculations.

This is undoubtedly the best bit of C# code/ Complete library I have ever come across.

Thankyou Soooo much !!!!

]]> By: Marcelo Ois Lagarde http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-140 Marcelo Ois Lagarde Thu, 05 Jun 2008 21:29:08 +0000 http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-140 Hi Mike, thanks for your excellent explanation. Your link to Vincenty's original work is very useful too. Reading the GeodeticCalculator class I wonder why do you implement equations 3, 4 and 6 inside the loop. I think if you postpone that after the convergence question you could gain an extra performance. Hi Mike, thanks for your excellent explanation. Your link to Vincenty’s original work is very useful too. Reading the GeodeticCalculator class I wonder why do you implement equations 3, 4 and 6 inside the loop. I think if you postpone that after the convergence question you could gain an extra performance.

]]> By: Mike Gavaghan http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-141 Mike Gavaghan Fri, 06 Jun 2008 00:38:58 +0000 http://www.gavaghan.org/blog/2007/08/06/c-gps-receivers-and-geocaching-vincentys-formula/#comment-141 Marcelo, Thanks for the kind words. Eqs. 3, 4, and 6 must be inside the loop because they change on each iteration. They are used to calculate the next value of lambda - and are derived from the previous value of lambda (albeit, through a complex sequence of calculations). A and B are functions of u2, u2 is a function of alpha, and alpha is a function of lambda. "deltaSigma" is similar (it's a function of B). The equation numbering is admittedly nonintuitive - but they aren't my numbers. They correlate directly back to Vincenty's publication. --Mike Marcelo,

Thanks for the kind words.

Eqs. 3, 4, and 6 must be inside the loop because they change on each iteration. They are used to calculate the next value of lambda - and are derived from the previous value of lambda (albeit, through a complex sequence of calculations). A and B are functions of u2, u2 is a function of alpha, and alpha is a function of lambda. “deltaSigma” is similar (it’s a function of B).

The equation numbering is admittedly nonintuitive - but they aren’t my numbers. They correlate directly back to Vincenty’s publication.

–Mike

]]>