Sun,Star Shots, Astronomic azimuth, hour angle method observation

Hi Everyone, For those of you have never done this,you do not know what you are missing.  I think every surveyor needs to do this ,if it is just for the fun or experience of doing it,a lot of old Deeds, even today have yesterday bearings,magnetic bearings or Declinations where once used not to long ago, a surveyor should be on guard, when taking Bearing from plats or old Deeds,  Astronomic azimuth were and are used in some cases for Geodetic surveys on today's Monuments.A direction determined from Sun or Star observations results in an astronomic azimuth which usually differs slightly from geodetic azimuth. Simply stated,  astronomic azimuth is base on the direction of the vertical and axis of rotation of the Earth. Geodetic azimuth is based on a mathematical approximation of the Earth shape The term Azimuth is define as a clockwise angle from astronomic North.This method  at one time was widely use to help improve the line of Directions that were being recorded on modern surveys. Modern surveyor no longer used magnetic bearings that had Declinations applied for their surveys, so before GPS this was the only way to determine North.and be more accurate than a Compass of yesterday surveys. In fact they are real accurate to say a lease.To do this you had to plan it all out. Lat. and Long had to be known and you had to have a real accurate time piece. The HP 41 CX has one of the most accurate clocks that is made in a calculator even today. I may have used it more than any other to do this. That includes the HP 48 GX and TDS Recon.But this is something to experience , if you have never done it. Looking at the Sun move (the Sun does not move) puts you in prospective with how fast we are moving thru space and more how fast we are turning. But this all had to be planed. If you had a filter you could take a Sun Shot, If not a Star Shot, but this means it had to be done at night.( Many Thanks to Ron Dry,Polaris shots Day Time) This was even more work to prepare for it, Both has to be done at certain times of the day or night.Your angle on the horizon can be to less and also to great, There are no midday Shots and the same for looking at Polaris , Also Clouds could stop you from taking one, also the Seasons ,in Winter you have less time in the day more at night . You have to take 6 sightings as fast as you can do them, This may seem hard but you get good at doing it.  But your work for property had to include it,to be completed.  Cell Towers when they came in all had to have this done for their alignment to North. GPS.replaced this method, but it is still required in some surveying. Like i mention you can find geodetic monuments that includes astronomic azimuth in their Data, When you look at them notice the different in this Azimuth and the Geodetic Azimuth.  So i will give you 2 links to download a Sokkia Celestrial Observation Hand Book on Ephemeris, this download is for educational purposes only from the three Authors who are all Professors,  this book has programs for HP 41CX,HP 42s and the HP 48GX,

Later in replys i will feature the 41cx and  48gx programs  with instructions and go over the notes. This was also one of the last books i used, You had to have this book to do it Plus knowing how to set your clock that you were using, then you would need a stopwatch with it or the calculators clocks, I have a large stack of these books, one for every year. So see how the Hour Angle Method HAM, was done.

Below i have attached two txt. files ,one is the 48 program and the other is the instructions to it.

"Thanks to Ron Dry for his input on Polaris During the Day"ésRuiz-jul-2013-g24731

This Content Originally Published by a land surveyor to Land Surveyors United Network

Views: 2272

See Your Saved Posts Timeline

Download Survey Documents-Members Only
Was this resource helpful? Show your appreciation with a comment below. 

Donations are how we exist and grow for the surveying community worldwide.

☇ Reply to this

Replies to This Discussion

Awesome... thanks for sharing Billy!  gonna look this over..

To shot the sun without a filter, the image of the sun and the telescope's reticle can be viewed on a white surface, such as a field book page or an index card. Don't do this on a total station because it will burn out the edm. DON'T LOOK AT THE SUN THROUGH THE TELESCOPE  WITHOUT A FILTER!

Hi Tom , That's why i didn't say anything about the paper, I have done this using a Transit,  but those day's are gone by. Everyone Filters Please, I was talking about doing a sun shot to my boss, and when it need to be done. In the meantime our new rod man hear all of this and went and turn our very new Total Station.  up to the Sun and was trying to look at the Sun before we saw him , he was blind in that eye for a few days and lucky and we were out of a Total Station . It needs to be said, to never leave you gun pointing toward the sky or Sun, and this has nothing to do with a Sun Shot ,this is everyday work practice. Yes i remember  focusing the cross hairs on the paper, Everyone should do this with a T.S. at lease one time, for the experience , a Polaris Observation also. Because it is night, it is very challenging , But can be very rewarding also.

thanks for bring that up.

Thanks Survenator, glad you like it,  checked out Translate,Rotate and Scale Recon TDS.

and I am going to show how to do Sun Shot with the 41 Cx also  HP 48GX TDS Programs

G. Ephemeris method and H. Almanac method .

Hi Tom, You mentioned the paper trick, I have use filters on Transits, this was a Great improvement over using a Compass, but i have also used Transits with solar attachment. In fact i used one on a "retracment" survey,we had it, plus a Transit,with a gold inlaid compass,that had a railroad  company's name Inlaid  inside the compass .I can not remember it, but it belong to one of the PLS and copies of the governments notes, quadrangle maps, all the data on Variations in Declination,secular,daily,annual and irregular,all the charts on all of this plus Isogonic Charts and local attraction notes, watches and stopwatches and 5 PLS,in which one was US Government Surveyor.  what a team, I was lucky to get to work on this project with them. IT seems like a life time ago, we had to run Section's lines that were cut into by a big lake,so we had to come from both sides,You could not see across it because of trees. The Solar Transit we did not use as much, it was less calculating, but also less accurate . But all this different data was recorded, the Section's corners had been lost. this was the reason for this survey.the lake was big problem. This area stayed Flooded ,most of the year. Just though i share it with you and everybody else.

Billy have you ever done solar observations using a Roelof Prism? A very handy filter that can be used with a Total Station as well.


Hi Bernie, Long time ,no see, Bernie No i have used many different  types of Prisms on the front eye piece . and night rods with night targets on Tribrachs and Flip up filters for the front, but i have never used this one , Does this one clamp to the front.and then flip, are  explain more how to use it. I hated those that just slip on and did not flip. You had to remove it while the barrel was free, i even put lube on some,so they would come off real easy, I was happy when i got the flip type.

This one looks very well made. you know they are very expensive now. even the cheap ones.. Glad to hear from you ,hope you are doing well. Thanks for the reply and the PIC, very good PIC.Hope to hear more from you.

Greetings Billy. Yes this prism mounts on the front of the scope. As you can see in the first image I posted, the darkener/prism section is 'hinged' so you can flip it off for sighting your backsight point. When sighting the sun with the prism flipped back on you will see 4 intersecting quadrants of the sun's coronal image that can be adjusted to narrow the cord intersects by turning the prism eye piece. You then turn your tangent screws so that the horizontal and vertical crosshairs intersect at the center of the 4 solar quadrants and the crosshairs are then parallel to the cords of all 4 overlapping arcs. It's a very accurate method. The sketch above what you see in the scope with the crosshairs intersecting the 4 images.

Hi Bernie, And thanks, No I never seen one like this, I did used one that had only one circle, and have used a lot of Transits that had the one circle, and solar attachments. This looks like a very scientific method, learning how to Trail the Sun for your time marks is a Art in itself, and thanks again for this Great information very educational. You get a Kudos from me.

Hi Bernie, I see the BLM mentions your Prism. again thanks for this. I had never  even heard of it. Do not know how.  But now i know of it.


Hi Everyone, This link pages and files ,contains Sun and Polaris Ephemerii for the year of 2016 for the use by land Surveyors.If just for fun, give it a try.

Sun and Polaris Ephemerii for the year of 2016 .

 Home Page

 and for those who like to try Day time Polaris, just be careful,

do not turn the scope toward the Sun at any time. are look at the sun

without a Filter. This is explained below,more data may be required.

Hi Everyone, I have been using this site,for quite some time,I first found it in Chrome Web store. I wanted it just for my love of Star Science and star locations. This  is neave .com. This site has a on line Planetarium, It is also interactive with you. If you are not familiar with star locations and like to learn the Night Shy, this is a good place to Start. It is also very Cool. In this you can see how to located Polaris, because it will produce, your night or day sky , from your Location. so you see the sky not just view of it , but a view from where ever you are at or located. At real time, so how Cool is that. so get this, Not for just to help you survey , but if you like. So here is some links. this is very neat. There is also many other things at,

neave .com  ,Games and also Zoom Earth, Nasa Satellite, Taken and updated every day.

also Live maps,Satellite, Earth Map, Aerial Maps. by Google,   Enjoy!

also available on chrome web store, Go there i could not get there link to work , it has a Info page on how it works also you can install there  for Chrome users.


Where Thousands of Professional Land Surveyors, Students of Surveying and Educators are United through Collaborative Knowledge and Purpose.

Land Surveyors Forum

Survey Abstract Coordinates

Started by John J Rodriquez in Introduce Yourself to the Community. Last reply by Kevin D. Allen on Friday. 13 Replies

Control surveying problem

Started by shree ram bhandari in Land Surveying Jobs. Last reply by Billy Brooks on Saturday. 11 Replies

Magnetic North Update

Started by Billy Brooks in Surveying Best Practices. Last reply by Billy Brooks Feb 6. 2 Replies


Started by Lalith Senanayake in Surveying Related Links. Last reply by shree ram bhandari on Tuesday. 4 Replies

Job Quotation

Started by Nitesh Shrestha in Land Surveying Jobs. Last reply by Nitesh Shrestha Jan 21. 3 Replies

Survey under tree canopy

Started by Massimo in Surveying Best Practices. Last reply by Maurice Heter on Saturday. 7 Replies

Mean Sea Level (MSL)

Started by Chuck Turlington in Geospatial Industry Types. Last reply by Kim Noblitt Jan 17. 6 Replies

Surface pro

Started by Malik in Surveying Field Tips and Tricks. Last reply by Kevin D. Allen Jan 7. 5 Replies


Started by Mthulisi Mloyi in Professional Advice for New Surveyors. Last reply by ⚡Survenator⌁ Jan 4. 2 Replies

Tools,Apps and Quick Guides


Help With Survey Equipment

Social Support For Equipment

Surveying Video Categories

Surveying Photo Categories

United States Hub Forums

International Surveyor Hub Forums

Resources for Company Owners

Land Surveyor Social Media

Surveyor Resources Collections

Getting Started & Newsletter

Featured Land Surveyor Hubs

Surveyor Birthdays

© 2019   © Created by Land Surveyors United   Powered by

Badges  |  Contact LSU  |  Privacy Policy  |  Terms of Service

Site Explorer