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Here’s how to set your Tripod up to point True South ( it will get you closer than a compass with magnetic declination offset )
Also Synscan Polar Alignment Routine using handcontroller
Finding Celestial True South using Solar noon ( Shadow ) method
Items needed
1 length of 12mm diameter timber dowel or rod with a 2mm deep hacksaw cut 90 degree criss cross on one end
2 x 3m pieces of 1mm diameter cotton builders string or similar
4 house bricks or pavers or weights
1 x straight edge , ruler or aluminium angle about 500 or 600mm long
1 x fine point permanent marker
1 x Stanley or similar 350mm builders bubble level
1 x PC or laptop with Stellarium down loaded or Smart phone
Location
Your observing location ( approx 2m2 ) or where you will set up your telescope mount should be a reasonably flat or level area with a good view of the sun around midday ( a paved, tiled or concrete ground is preferable) At a remote site you will have to clear the ground of rocks and debris to leave a fairly clear flat area
Procedure
Setting up for your solar noon shadow
Erect timber dowel or rod vertically at your telescope mount location and use the 2 strings to anchor the dowel to the ground like tent guy ropes at north , south , east and west. Use bricks , pavers or weights to hold down the strings tight so dowel sits firm upright. Now use a bubble level vertically against the dowel to ensure it is 90 degrees on all 4 sides N,S,E, W, The hacksaw cuts in the top of the dowel make it easy to make fine adjustments
either way
Finding Solar Noon Time
(Using a Planetarium like Stellarium )
Start your PC or laptop in the morning and open Stellarium
Move your planetarium view to the left or right until you reach the north (N) cardinal point and move up until you see the Sun
Click on the Sun and you will see it’s read out data on the top left of the screen
Now open the Time window and move the time forward until you view the Sun bisecting the north meridian line or until read out data on Az/ Alt degrees goes from 359 degrees to 0 degrees
At that very point and time , record the time from the clock ( eg 12.35pm )This time is your Solar noon time which you will use later
(Finding Solar noon on a website )
Most meteorological websites show solar noon times at or near your location
Marking your Celestial True South Line
Go to your location about 15 minutes before the designated solar noon time with your smart phone , ruler or straight edge and permanent fine tip marker
The timber dowel or rod should be casting a 500mm long thin shadow across the ground towards the south
At exactly solar noon time , mark a line on the ground from the centre base or the timber dowel or rod outward along the exact centre of the shadow to at least 500mm out. Use your ruler or straight edge and be as precise as you can.The more precise you are , the closer you will be to true south and eventually polar alignment.
This line represents the True South line and can now be used again and again when you set up your tripod , mount and telescope
I found the above method of finding True South far more accurate than any compass with magnetic declination or phone app etc....
Setting up a HEQ5 ,NEQ6 and EQ6-R Tripod
NB: This procedure is based on having your True South line already marked on the ground from a previous procedure ( length of true south line marked on ground approximately 500mm long or alternatively 2 fixed points marked on the ground 500mm apart)
1/ Open your tripod fully out and extend all 3 legs out by about 100mm then lock them
2/ Place foot of front tripod leg marked “N” directly on True South line and roughly line up the 2 rear tripod legs equally spaced in respect to the True South line
3/ Level the base platform of your tripod by adjusting the legs in or out as required .Check level of the tripod base in both north/south and east/west directions using a good quality builders aluminium bubble float level.Level the base as accurate as you can then lock the tripod leg adjusters nice and tight.
4/ Extend out your True South Line along the ground just past the intersection of the 2 rear tripod legs using a string line, aluminium angle or a straight edge. The feet of both rear tripod legs must be equidistant from the intersection of the extended True South Line. When adjusting make sure you only move the 2 rear tripod legs left or right whilst keeping the front tripod leg “N” stationary or pivoting but not moving off the True South Line
5/ Once the 2 rear tripod legs are equidistant from the true south line , the tripod is now set up level and pointing to Celestial True South
6/ Ensure you take care in setting up the tripod and measuring accurately to the nearest millimetre.This will assist the accuracy of your polar alignment procedure.
Synscan Polar Alignment Routine V3 and V4 Skywatcher EQ Mounts ( used when no view of SCP )
1/ You will be using a 2 Star Alignment to start the process so nominate your 2 Alignment Stars on the same side of the meridian, one of which will be your Polar Alignment Star ( Alignment Stars should be fairly bright stars where possible to ensure they appear in the Synscan hand controllers data base, usually greater than magnitude 2.5 )
(Alignment stars for polar alignment ideally should be located between 35 degrees and 70 degrees in Altitude and no more than 50 degrees in Azimuth from the meridian) Important - Your Polar Alignment Star or 1st Star Alignment Star will be the one closest to the south meridian. To assist with locating and nominating your Alignment Stars use a Star Chart, a Planetarium like Stellarium or Cartes Du Ciel.
2/ Complete a 2 Star Alignment generally in accordance with Syncan 2 Star Alignment procedure. Start with your 1st Alignment Star close to the south meridian ( this will be your Polar Alignment Star as well ) and then 2nd Alignment Star away from south meridian no further than 50 degrees in Azimuth
3/ After completing a 2 Star Alignment press “Menu” then “Alignment” then “Polar Alignment” and then “Enter”
4/ The screen will display “ Select Star”. Scroll through list of stars until you find your previous nominated Polar Alignment Star and press “Enter”
5/ Mount will slew to the selected Polar Alignment Star
6/ Use direction keys on the hand controller to centre the Polar Alignment Star in the telescope eye piece reticle or Computer screen reticle. Once centred press “Enter”
7/ The hand controller screen will now display the polar alignment error ( degrees: minutes: seconds) then press “Enter” to proceed
8/ The mount will now slew to the new Altitude position. Now use the Altitude adjustment bolts only to move the Star to the closest point to the centre of FOV on the reticle eye piece or computer screen reticle. Remember this position and then press “Enter” to show the new polar alignment error ( degrees: minutes: seconds )
9/ Press “Enter” again and mount will slew to the new Azimuth position. Now use the Azimuth bolts only to move the Star to the closest point where the Star was centred in step 8. Press “Enter” to show the new polar alignment error
10/ Press “Enter” again to end the Polar Alignment procedure
11/ Go back to the “Alignment” menu in the hand controller and execute another “2 Star Alignment”. 1st Alignment Star will be your Polar Alignment Star which you should be already centred on from the previous Polar Alignment routine and 2nd Alignment Star is further away from the south meridian.Once the 2 Star Alignment is completed , the polar alignment error will be displayed on the hand controller ( degrees: minutes : seconds )
12/ Repeat the above procedures ( iterations) 2 or more times as required to reduce your polar alignment error below 1 arc second in both Altitude and Azimuth.
Polar Alignment Error displayed on hand controller should show as many zeros as possible
Eg: 1 arc minute error 000 01’ 00” Eg: 20 arc sec error 000 00’ 20”
Try and get below 1 arc minute error in both Altitude and Azimuth if conditions and time permit.
13/ Note: you must perform a 2 Star Alignment before you start with a Polar Alignment routine each time
14/ To improve accuracy of your Star centering and alignments , de focus the star slightly into a small donut shape, this way you can perform more accurate centering operations looking into your reticle eye piece or at your computer screen reticle
15/ The 2 Star Alignment stars you use for Polar Alignment maybe different from 2 Star Alignment stars you use for locating objects ( Goto) as the accuracy of Goto may improve with a wider distance between alignment stars in Azimuth.The 2 Star Alignment stars for Polar Alignment are fairly close to each other near the meridian and only span a small part of the night sky. The Polar Alignment routine obtains better results ( lower error ) when Alignment stars are within 50 degrees apart in Azimuth and closer to the south meridian at between 35 degrees and 70 degrees in Altitude.
16/ With some experience the Synscan Polar Alignment routine can usually be completed with sub arc minute PA error in around 15 to 20 minutes depending on seeing conditions
17/ Note: Star Alignment and Polar Alignment are two different processes
Star Alignment is used to tell the mount exactly its location in the night sky on an object using singular or multiple pointing model algorithms.
Polar Alignment is aligning the central axis of the mount and telescope to the South Celestial Pole using the Altitude and Azimuth adjustments. Depending on the accuracy of Polar Alignment,the celestial object will remain stationary in the FOV for at least a minute or so before any noticeable drift.
However Polar Alignment and Star Alignment do affect each other when adjustments are made. An adjustment of Altitude or Azimuth affects your star alignment accuracy, that’s why you perform a 2 Star Alignment after PA is adjusted.
Hope the above helps
Cheers
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