The HP 35s Calculator—A Field Surveyor's Companion—Part 3-Traverse

A 416Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

"But no longer to light candles to see the sun by, let me come to my business, which is to speak something concerning the following book; and if you ask, why I write a book of this nature, since we have so many very good ones already in our own language? I answer, because I cannot find in those books, many things, of great consequence, to be understood by the Surveyor. I have seen young men, in America, often nonplus’d so, that their books would not help them forward, particularly in Carolina, about laying out lands, when a certain quantity of acres has been given to be laid out five or six times as broad as long. This I know is to be taught by a mathematician; yet to such as have no more of this learning, than to know how to measure a field, it seems a difficult question: and to what book already printed of Surveying shall they repair to, to be resolved?"
—John Love, Geodaesia: The Art of Surveying and Measuring of Land Made Easie circa 1688 A.D.

John Love’s observations distinguish the Professional Surveyor in America from the singular technical act of measurement. Love identifies the natural cause for professional development and through his work he championed that cause on the American Continent. Rather than entrusting his profession to European Academia he asserted his own undivided professional discretion towards the development of others and openly apportioned his knowledge. Love truly recognized that the Art of Surveying cannot be wholly conveyed from the confined walls of any Institution. I have found that Love’s presentation in 1688 is archetypical of the following references sitting on my bookshelf: Davies 1870 Elements of Surveying and Leveling; the 1913 I.C.S. Civil Engineer’s Handbook; Davis, Foote, and Rayner’s 1928 Surveying; Bouchard and Moffit’s 1969 Surveving Fifth Edition; and Wolf and Ghilani’s 2006 Elementary Surveying. Geodaesia is relevant 326 years later because it shares a true professional understanding of Land Surveying. Imbibing that knowledge recorded in Geodaesia is more binding to professional development than any Pavlovian memorization exercise associated with software keystrokes. It is in this light that our beloved HP calculator becomes a positive augmentation to our individual professional knowledge.

This Month’s Programs
Traverse is a "point and direction" style program. Traverse azimuth entry is based on a 360° north oriented zero circle accepted in decimal degrees. I have included an option to key in p.o.b. coordinates or recall point coordinate values from storage.


This Month We Have a Bonus Equation!

Add this equation to your EQN library. It converts azimuth values from the Argand Plane into a 360° North based system. The Argand Plane is HP’s angular reference plane in which zero is east and the angles progress either left (counterclockwise, positive, north) or right (clockwise, negative, south) of the latitudinal axis to 180°. This is apparent when complex coordinates are both negative (The southwest quadrant to us rope stretchers, right?) and the argument function (or a polar display conversion) yields a modulus (azimuth) for example of -135°. Simply run this equation with the argument of the Argand value (-135°) in the X-reg. The result being 225°. There’s a similar function in Excel named MOD. It follows this form:

=MOD(450-the Argand value,360)

So far we have a pair of tools to create, store and review coordinates. Traverse should be somewhat self-explanatory to most folks familiar with COGO. Anyone that
desires a sample data and/or any additional instructions should not hesitate to contact me. In the next installment I will present an inverse program. Hopefully the information presented herein is clear and genuinely explanatory. Please do not hesitate to send any comments, concerns, questions, or criticism to

Jason Foose is the County Surveyor of Mohave County Arizona. He has been licensed since 11111010000 and believes there are 10 types of people in the world, those that understand binary and those who don’t.

Polecat of the Month

The Polecat of the Month Award goes to Mark Leasure, L.S. I. of GMS, INC. located in Colorado Springs, Co. Mark dug up a grub worm in line H016 of the "Points" listing located on page 15 of the September 2014 issue. The line should read "H016 EQN N x 1i0 + E 190". My apologies to the readers and staff for my oversight and as well as my undying gratitude to Mark Leasure. Thanks for the catch and a toast to our polecat of the month as he dons his orange vest to swim in the melee of traffic that the locals refer to as I-25!

A 416Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

About the Author

Jason Foose, PS

Jason Foose originally hails from the Connecticut Western Reserve Township 3, range XIV West of Ellicott’s Line Surveyed in 1785 but now resides in Township 21 North, Range 17 West of the Gila & Salt River Base Line and Meridian. He is also the Managing Editor of the magazine.