@geeoddmike?ÿ ?ÿI understand. If you ever get to Tombstone, AZ?ÿ let me know and I will pull out my toys and you can have some fun.
@geeoddmike?ÿ I have that pub.?ÿ I keep thinking it was published someplace else but can't remember where.
While I prefer reading peer-reviewed literature, the cost to access such material is excessive. I hope that government entities like the US NGS will start to publish in these journals using the ??Open Access? option.?ÿ
?ÿ
?ÿ
The discussion of observer bias sort of circles back to the original post. The MS60, with its 0.5" accuracy, delivers repeatability of astronomic bearings of 0.3" according to the slide in the linked presentation. The MS60 removes the observer bias.
I'm curious, since we brought up the T4, which has a 0.1 arc second precision (horizontal) and 0.2 arc second precision (vertical), what sort of accuracy in astronomic bearings was it able to achieve? Is it still the best geodetic theodolite or since modern electronic instruments have tilt compensation, are the newer instruments better for geodetic bearings? Would a T4 deliver better than 0.3" accuracy?
A lot of time and money was expended on the Transcontinental Traverse (TCT) program in the 60's and 70's. Years ago I had access to the observations in the NGS database (security issues killed that) and I wanted to extract a really long line across the US and compare against high GPS positions to see if they really met the 1:1,000,000 (1 ppm) accuracy that was their goal. The specs for that (which evolved over time) make for interesting reading.?ÿ
@bill93 About MICA: the Delta-T file is out of date, so you would have to work in Terrestrial Time (formerly known as ephemeris time) and correct for Delta-T separately. Unless someone knows how to construct a Delta-T correction file that would work with the program.
@shawn-billings?ÿ There are many factors that affect the accuracy of?ÿany Theodolite. If it's a Wild T2, Wild T4 or the MS60.
Removing observer bias is just one of them(and can be one of the largest) but there are others. Its still has wobble in the horizontal and vertical axis.?ÿ
You mention the T4 and precision: that's?ÿNOT precision it's just reading direct to 0.1 seconds in the horizontal and reading 0.2 seconds in the vertical. Leveling bubbles can only be made so accurate. For a report on the bubbles of a Wild T4 theodolite see Bulletin Geodesique?ÿ #81, Sept.?ÿ 1966 page 5-11 (The Dependence of the level-Sensitivity on the position and Length of the bubble on the Wild T-4 Theodolite). It is very important to read this paper if using a Wild T-4.
?ÿ
?ÿ
?ÿ
@john-hamilton?ÿ ?ÿI am having trouble understanding some of your post above about the TCT.
1. "security issued killed that"?ÿ ?ÿ?
2."compare against high GPS positions"?ÿ ?ÿdo you mean high precision GPS positions?
3. "specs... made interesting reading"?ÿ What about results of the comparison
?ÿ
1) I was given a login to a server at NGS that I could telnet into and access conventional observations (not GPS) from the database and extract the values for use in my adjustments. As hacking became a problem, they got rid of telnet access, and my ability to use that was cutoff.?ÿ
2) High accuracy GPS, I inadvertently left out the word accuracy. My idea was to extract the observations for a thousand mile line, run an adjustment, and use the high accuracy GPS positions to see what the accuracy achieved was. However, what was lacking was vertical info, such as vertical angles or height differences. They had directions, mark to mark distances, azimuths, astro latitudes and longitudes, but not vertical angles for the distances.?ÿ Here is, for example, all of the observations from/to APPAL...
c ************************************************************************************************************************************
c 10147204 APPAL N393211.46258 W0773618.17139 A 83 JV3581 MD 043 1958 (1991)
c ASTRO LATITUDE N N393215.5 S A3858 19680822 104 N 4 0.28 A156
c ASTRO LONGITUDE W0773633.43 T A3858 19680824 104 N 5 0.34 A156
c 389.6153 A 88 N 00000025
c PAC_SAC= [ ]
c ************************************************************************************************************************************
c
c 10147204 APPAL JV3581
c ST/COUNTY= MD/(043)WASHINGTON
c STAMPING = APPAL 1957
c MONUMENT = DS TRIANGULATION STATION DISK
c SETTING = 7 SET IN TOP OF CONCRETE MONUMENT
c STABILITY= C MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO SURFACE MOTION -
c MAGNETIC =
c
c
c LAST RECOVERED
c TYPE COND DATE AGENCY SAT TRANS PACK
c ---- ---- -------- ------ --- ----- ----
c H G 1968 CGS P 0000
c
c (Year=1958 Agency=CGS Type=U Cond=S)
c ------------------------------------------------------------------------
c THE STATION IS LOCATED ABOUT 13 MILES NORTHWEST OF FREDERICK,
c 10 MILES SOUTHEAST OF HAGERSTOWN AND JUST NORTH OF U.S. HIGHWAY
c 40 WHERE IT CROSSES SOUTH MOUNTAIN. THE MARK IS 40 FEET WEST OF
c A FENCE, 15 FEET NORTHEAST OF AN 8 INCH BLAZED TREE, 15 FEET
c SOUTHWEST OF A 4 INCH BLAZED TREE, 7 FEET NORTHWEST OF A WITNESS
c POST AND IN THE CENTER OF AN OLD TRAIL. THE MARK PROJECTS
c 4 INCHES AND THE DISK IS STAMPED APPAL 1957.
c
c REFERENCE MARK NO. 1 IS 20 FEET EAST OF THE CENTER OF OLD TRAIL
c AND 10 FEET WEST OF FENCE. THE MARK PROJECTS 4 INCHES AND THE
c DISK IS STAMPED APPAL NO 1 1957.
c
c REFERENCE MARK NO. 2 IS 12 FEET NORTH OF CUT BANK OF
c HIGHWAY. THE MARK PROJECTS 4 INCHES AND THE DISK IS STAMPED
c APPAL NO 2 1957.
c
c NO AZIMUTH MARK WAS SET.
c
c TO REACH FROM THE JUNCTION OF U.S. HIGHWAYS 340 AND 40 IN THE
c WEST EDGE OF FREDERICK, GO WEST ON HIGHWAY 40 2.2 MILES TO THE
c JUNCTION OF ALTERNATE U.S. HIGHWAY 40. CONTINUE ON U.S. HIGHWAY
c 40 8.3 MILES TO STATE HIGHWAY 153. CONTINUE ON HIGHWAY 40 3.1
c MILES TO THE TOP OF SOUTH MOUNTAIN AND SIGN APPALACHIAN TRAIL,
c TURN RIGHT FOR ABOUT 50 YARDS, TURN RIGHT ABOUT 50 YARDS, TURN
c RIGHT ABOUT 300 FEET ON OLD TRAIL TO THE STATION.
c
c HEIGHT OF LIGHT ABOVE STATION MARK 23 METERS.
c 2.4 MI SE FROM MOUNT LENA.
c 1.2 MILES SOUTHEAST ALONG THE MAIN ROAD FROM THE JUNCTION OF SAN
c MAR ROAD AT MOUNT LENA, THENCE 1.0 MILE SOUTH ALONG U.S. HIGHWAY
c 40, THENCE 0.05 MILE NORTH ALONG A GRAVELED ROAD, THENCE 0.1 MILE
c EAST ALONG A TRACK ROAD, THENCE 0.05 MILE SOUTH, 75 FEET NORTHEAST
c OF THE TOP OF A CUT BANK FOR U.S. HIGHWAY 40, 7.0 FEET NORTH OF A
c WITNESS POST, AND SET IN THE TOP OF A CONCRETE POST PROJECTING
c 0.6 FOOT ABOVE THE GROUND.
c
c (Year=1968 Agency=CGS Type=U Cond=G)
c ------------------------------------------------------------------------
c THE STATION AND REFERENCE MARKS WERE RECOVERED IN GOOD
c CONDITION. DIRECTION AND DISTANCE TO THE REFERENCE MARKS CHECKED
c ADEQUATELY.
c
c THE LAND ON WHICH THE STATION IS ESTABLISHED IS OWNED BY A
c MR. H. M. IRWIN.
c
c AN AZIMUTH MARK HAS NOW BEEN ESTABLISHED AND IS VISIBLE FROM THE
c STATION MARK.
c
c A NEW DESCRIPTION TO REACH THE STATION FOLLOWS--
c
c THE STATION IS REACHED FROM THE JUNCTION OF U. S. HIGHWAYS 40 WEST
c AND 15 NORTH IN FREDERICK BY GOING NORTHWEST ON HIGHWAY 40 FOR
c 1.6 MILES TO THE JUNCTION OF U. S. HIGHWAY 40 ALTERNATE. CONTINUE
c NORTHWEST ON HIGHWAY 40 FOR 8.3 MILES TO THE JUNCTION OF STATE
c HIGHWAY 153. CONTINUE NORTHWEST ON HIGHWAY 40 FOR 2.0 MILES TO
c THE AZIMUTH MARK ON THE LEFT IN A HIGHWAY CONCRETE CURB AS
c DESCRIBED BELOW. CONTINUE STRAIGHT AHEAD ON HIGHWAY 40 FOR
c 1.15 MILES TO A PRIVATE ROAD RIGHT WHICH BELONGS TO A MR.
c FREEMAN. TURN RIGHT AND GO 0.15 MILE TO THE END OF THE ROAD,
c A POLE GATE AND MR. FREEMANS HOME. MR. FREEMAN HAS TWO
c KEYS FOR TWO LOCKED GATES WHICH ARE IN ROUTE TO THE STATION FROM
c THIS POINT. PASS THROUGH THE POLE GATE AND CONTINUE ACROSS A
c PASTURE LOT FOR ABOUT 60 FEET TO A LOCKED GATE. PASS THROUGH
c THE GATE AND CONTINUE ACROSS A PASTURE LOT FOR ABOUT 250 FEET
c TO ANOTHER LOCKED GATE. PASS THROUGH THE GATE, THEN LEFT
c AND GO SOUTHWESTERLY ON AN OLD WOODS ROAD FOR ABOUT 300 FEET TO
c A ROAD FORK. KEEP LEFT AND GO STRAIGHT AHEAD ON ROAD FOR ABOUT
c 200 FEET TO THE STATION MARK IN THE ROAD.
c
c THE STATION MARK (NOTE 1A AND 7A) IS STAMPED APPAL 1957 AND
c PROJECTS ABOUT 4 INCHES.
c
c REFERENCE MARK 1 (NOTE 11A) IS STAMPED APPAL NO 1 1957 AND
c PROJECTS ABOUT 4 INCHES.
c
c REFERENCE MARK 2 (NOTE 11A) IS STAMPED APPAL NO 2 1957 AND
c PROJECTS ABOUT 4 INCHES.
c
c THE AZIMUTH MARK IS A CORPS OF ENGINEERS, U. S. ARMY DISK
c STAMPED APPAL AZ MK ARMY MAP SERVICE 1968, CEMENTED IN A DRILL
c HOLE IN THE TOP OF A HIGHWAY CONCRETE CURBING WHICH IS ABOUT
c 6 INCHES HIGHER THAN THE HIGHWAY LEVEL. IT IS ABOUT 250 FEET
c SOUTHEAST OF A DRIVEWAY WHICH LEADS TO THE WILLIAMS CONSTRUCTION
c COMPANY, 27 FEET SOUTHWEST OF THE CENTERLINE OF U. S. HIGHWAY
c 40, 4.5 FEET NORTHEAST OF A METAL WITNESS POST WHICH HAS A METAL
c SIGN ATTACHED AND 2.0 FEET NORTHWEST OF THE SOUTHEAST END OF THE
c CONCRETE CURBING.
c
c HEIGHT OF LIGHT ABOVE STATION MARK 72.8 FEET.
c
c AIRLINE DISTANCE AND DIRECTION FROM NEAREST TOWN
c 13 MILES NORTHWEST OF FREDERICK.
c
c 1 14242 APPAL 19680923 10976974 OCTIN N 0.5 1 N 0000000.00 GAITHMUN *
c 1 14242 APPAL 19680923 10976975 OCTIN RM A AMS 1968 N 0.5 1 N 0000602.25 GAITHMUN *
c 1 14242 APPAL 19680923 10977160 SPEILMAN RM A N 0.5 1 N 1584352.51 GAITHMUN *
c 1 14242 APPAL 19680923 10977161 SPEILMAN RM 3 N 0.5 1 N 1584915.62 GAITHMUN *
c 4 14242 APPAL 19680923 10976964 CATOCTIN MTN RADIO WFMD FM MST N 3.2 1 N 3363924.20 GAITHMUN *
c 0 14242 APPAL 19680923 11351571 APPAL AZ MK N 005.1 1 A 3451307.40 GAITHMUN *
c 0 14242 APPAL 19680923 11351571 APPAL AZ MK N 005.1 2 Z 0000000.00 GAITHMUN *
c 0 14242 APPAL 19680923 11351573 APPAL RM 2 N 060.1 2 R 0945141.30 GAITHMUN *
c 0 14242 APPAL 19680923 11351572 APPAL RM 1 N 060.1 2 R 2871026.50 GAITHMUN *
c 1 14242 APPAL 19680924 10976974 OCTIN N 0.5 3 N 0000000.00 GAITHMUN *
c 1 14242 APPAL 19680924 10976975 OCTIN RM A AMS 1968 N 0.5 3 N 0000600.94 GAITHMUN *
c 1 14242 APPAL 19680924 10977160 SPEILMAN RM A N 0.5 3 N 1584352.09 GAITHMUN *
c 1 14242 APPAL 19680924 10977161 SPEILMAN RM 3 N 0.5 3 N 1584914.82 GAITHMUN *
c 1 14242 APPAL 19680927 10976974 OCTIN N 0.5 4 N 0000000.00 GAITHMUN *
c 1 14242 APPAL 19680927 10976975 OCTIN RM A AMS 1968 N 0.5 4 N 0000601.84 GAITHMUN *
c 1 14242 APPAL 19680927 10977161 SPEILMAN RM 3 N 0.5 4 N 1584915.28 GAITHMUN *
c 1 14242 APPAL 19680927 10976974 OCTIN N 0.5 5 N 0000000.00 GAITHMUN *
c 1 14242 APPAL 19680927 10977160 SPEILMAN RM A N 0.5 5 N 1584352.46 GAITHMUN *
c 1 14242 APPAL 19680927 10976974 OCTIN N 0.5 6 N 0000000.00 GAITHMUN *
c 1 14242 APPAL 19680927 10977160 SPEILMAN RM A N 0.5 6 N 1584351.21 GAITHMUN *
c 2 11611 APPAL 19580127 10977002 LAMBS KNOLL N 1.0 1 N 0000000.00 MHSHFBLT *
c 0 11611 APPAL 19580127 11351573 APPAL RM 2 N 060.1 1 R 0264728.90 MHSHFBLT *
c 0 11611 APPAL 19580127 11351572 APPAL RM 1 N 060.1 1 R 2190730.70 MHSHFBLT *
c 4 11611 APPAL 19580127 10976964 CATOCTIN MTN RADIO WFMD FM MST N 3.2 1 N 2832254.90 MHSHFBLT *
c 4 11611 APPAL 19580127 10976957 MYERSVILLE AM TEL TWR KGB 25 O 3.2 1 N 2863622.30 MHSHFBLT *
c 2 11611 APPAL 19580127 10977156 SPEILMAN N 0.7 2 N 0000000.00 MHSHFBLT *
c 2 11611 APPAL 19580127 10173539 WAGNERS N 0.7 2 N 0222528.23 MHSHFBLT *
c 2 11611 APPAL 19580127 10213934 DAYSDAIR N 0.7 2 N 0231138.17 MHSHFBLT *
c 3 11611 APPAL 19580127 10137533 JERU N 0.8 2 N 1861525.93 MHSHFBLT *
c 2 11611 APPAL 19580127 10976961 HIGH KNOB 2 N 0.7 2 N 1951552.71 MHSHFBLT *
c 2 11611 APPAL 19580127 10977002 LAMBS KNOLL N 0.7 2 N 2543840.92 MHSHFBLT *
c 3 11766 JERU 19580129 10147204 APPAL N 0.8 1 A 0000000.00 MHSHFBLT *
c 0 11766 JERU 19580129 10137535 JERU RM 2 N 060.1 1 R 0143331.80 MHSHFBLT
c 0 11766 JERU 19580129 10137534 JERU RM 1 N 060.1 1 R 1842258.30 MHSHFBLT
c 3 11766 JERU 19580129 10126054 CANDY N 0.8 1 N 1875455.79 MHSHFBLT
c 2 11766 WAGNERS 19580123 10147204 APPAL N 0.7 1 N 0000000.00 MHSHFBLT *
c 2 11766 WAGNERS 19580123 10977002 LAMBS KNOLL N 0.7 1 N 0354555.02 MHSHFBLT
c 3 11766 WAGNERS 19580123 10977086 FAHRNEY N 0.8 1 N 0983659.38 MHSHFBLT
c 2 11766 WAGNERS 19580123 10977156 SPEILMAN N 0.7 1 N 1483950.94 MHSHFBLT
c 2 11766 WAGNERS 19580123 10213934 DAYSDAIR N 0.7 1 N 1812145.91 MHSHFBLT
c 2 11766 WAGNERS 19580123 10147204 APPAL N 1.4 2 N 0000000.00 MHSHFBLT *
c 0 11766 WAGNERS 19580123 10173541 WAGNERS RM 2 N 060.1 2 R 1700656.40 MHSHFBLT
c 0 11766 WAGNERS 19580123 11353999 WAGNERS AZ MK N 005.1 2 A 1713531.40 MHSHFBLT
c 4 11766 WAGNERS 19580123 10977107 HAGERSTOWN RADIO STA WARK MAST N 3.2 2 N 1790922.20 MHSHFBLT
c 0 11766 WAGNERS 19580123 10173540 WAGNERS RM 1 N 060.1 2 R 3531805.50 MHSHFBLT
c 2 11766 WAGNERS 19580206 10147204 APPAL N 0.8 3 N 0000000.00 MHSHFBLT *
c 2 11766 WAGNERS 19580206 10977156 SPEILMAN N 0.7 3 N 1483950.44 MHSHFBLT
c 2 11766 WAGNERS 19580206 10213934 DAYSDAIR N 0.8 3 N 1812145.24 MHSHFBLT
c 2 11766 HIGH KNOB 2 19580205 10976910 BART N 0.7 4 N 0000000.00 MHSHFBLT
c 2 11766 HIGH KNOB 2 19580205 10976952 DETRICK N 0.7 4 N 0004401.16 MHSHFBLT
c 2 11766 HIGH KNOB 2 19580205 10158803 FRED N 0.7 4 N 0272627.38 MHSHFBLT
c 3 11766 HIGH KNOB 2 19580205 10976956 GAMBRILL N 0.9 4 N 0651156.42 MHSHFBLT
c 2 11766 HIGH KNOB 2 19580205 10976967 GLARE N 0.7 4 N 0772406.69 MHSHFBLT
c 3 11766 HIGH KNOB 2 19580205 10976971 KLIPP N 0.8 4 N 0890351.48 MHSHFBLT
c 2 11766 HIGH KNOB 2 19580205 10977002 LAMBS KNOLL N 0.7 4 N 1495829.82 MHSHFBLT
c 2 11766 HIGH KNOB 2 19580205 10147204 APPAL N 0.7 4 N 1985645.96 MHSHFBLT *
c 1 14242 OCTIN 19680912 10116353 MILL N 0.5 2 N 0000000.00 GAITHMUN
c 1 14242 OCTIN 19680912 10976975 OCTIN RM A AMS 1968 N 11.6 2 N 1094118.58 GAITHMUN
c 1 14242 OCTIN 19680912 10147204 APPAL N 0.5 2 N 1773222.24 GAITHMUN *
c 2 14242 OCTIN 19680912 10976971 KLIPP N 1.0 2 N 2225203.34 GAITHMUN
c 0 14242 OCTIN 19680912 11353269 OCTIN AZ MK N 005.1 2 A 2711426.95 GAITHMUN
c 1 14242 OCTIN 19680919 10116353 MILL N 0.5 3 N 0000000.00 GAITHMUN
c 1 14242 OCTIN 19680919 10976975 OCTIN RM A AMS 1968 N 11.6 3 N 1094052.52 GAITHMUN
c 1 14242 OCTIN 19680919 10147204 APPAL N 0.5 3 N 1773221.58 GAITHMUN *
c 2 14242 OCTIN 19680919 10976971 KLIPP N 1.3 3 N 2225203.80 GAITHMUN
c 0 14242 OCTIN 19680919 11353269 OCTIN AZ MK N 005.1 3 A 2711425.92 GAITHMUN
c 1 14242 OCTIN RM A AMS 1968 19680912 10147204 APPAL N 0.5 1 N 0000000.00 GAITHMUN *
c 0 14242 OCTIN RM A AMS 1968 19680912 11353269 OCTIN AZ MK N 005.1 1 A 0941543.86 GAITHMUN
c 1 14242 OCTIN RM A AMS 1968 19680912 10976974 OCTIN N 11.6 1 N 1120256.60 GAITHMUN
c 1 14242 OCTIN RM A AMS 1968 19680912 10116353 MILL N 0.5 1 N 1821638.63 GAITHMUN
c 1 14242 OCTIN RM A AMS 1968 19680919 10147204 APPAL N 0.5 2 N 0000000.00 GAITHMUN *
c 1 14242 OCTIN RM A AMS 1968 19680919 10116353 MILL N 0.5 2 N 1821639.06 GAITHMUN
c 1 14242 OCTIN RM A AMS 1968 19680919 10147204 APPAL N 1.0 3 N 0000000.00 GAITHMUN *
c 0 14242 OCTIN RM A AMS 1968 19680919 11353269 OCTIN AZ MK N 005.1 3 A 0941543.08 GAITHMUN
c 1 14242 OCTIN RM A AMS 1968 19680919 10976974 OCTIN N 11.6 3 N 1120227.88 GAITHMUN
c 2 11766 LAMBS KNOLL 19580127 10977156 SPEILMAN N 0.7 1 A 0000000.00 MHSHFBLT
c 2 11766 LAMBS KNOLL 19580127 10173539 WAGNERS N 0.7 1 N 0311052.37 MHSHFBLT
c 2 11766 LAMBS KNOLL 19580127 10147204 APPAL N 0.7 1 N 0473810.44 MHSHFBLT *
c 2 11766 LAMBS KNOLL 19580127 10976961 HIGH KNOB 2 N 0.7 1 N 1191704.93 MHSHFBLT
c 0 11766 LAMBS KNOLL 19580127 11352864 LAMBS KNOLL RM 1 N 060.1 1 R 2200200.90 MHSHFBLT
c 0 11766 LAMBS KNOLL 19580127 11352865 LAMBS KNOLL RM 2 N 060.1 1 R 3395151.30 MHSHFBLT
c 2 11766 LAMBS KNOLL 19580205 10147204 APPAL N 0.7 2 N 0000000.00 MHSHFBLT *
c 2 11766 LAMBS KNOLL 19580205 10976961 HIGH KNOB 2 N 0.7 2 N 0713854.89 MHSHFBLT
c 2 11766 LAMBS KNOLL 19580205 10976967 GLARE N 0.7 2 N 1082322.62 MHSHFBLT
c 2 11766 SPEILMAN 19580123 10216661 HUTZEL N 0.7 2 N 0000000.00 MHSHFBLT
c 2 11766 SPEILMAN 19580123 10213934 DAYSDAIR N 0.7 2 N 0174151.32 MHSHFBLT
c 2 11766 SPEILMAN 19580123 10173539 WAGNERS N 0.7 2 N 0444719.95 MHSHFBLT
c 2 11766 SPEILMAN 19580123 10147204 APPAL N 0.7 2 N 0534203.46 MHSHFBLT *
c 2 11766 SPEILMAN 19580123 10977002 LAMBS KNOLL N 0.8 2 N 0804234.40 MHSHFBLT
c 2 11766 SPEILMAN 19580206 10213934 DAYSDAIR N 0.7 6 N 0000000.00 MHSHFBLT
c 2 11766 SPEILMAN 19580206 10173539 WAGNERS N 0.7 6 N 0270528.39 MHSHFBLT
c 2 11766 SPEILMAN 19580206 10147204 APPAL N 0.7 6 N 0360009.60 MHSHFBLT *
c 1 14242 SPEILMAN RM A 19680926 10977163 DAVIS N 0.5 3 N 0000000.00 GAITHMUN
c 1 14242 SPEILMAN RM A 19680926 10977161 SPEILMAN RM 3 N 10.3 3 R 0804447.05 GAITHMUN
c 0 14242 SPEILMAN RM A 19680926 11353748 SPEILMAN AZ MK RESET N 005.1 3 A 1501344.41 GAITHMUN
c 1 14242 SPEILMAN RM A 19680926 10147204 APPAL N 0.5 3 N 1973802.62 GAITHMUN *
c 1 14242 SPEILMAN RM A 19681001 10977163 DAVIS N 0.5 1 N 0000000.00 GAITHMUN
c 1 14242 SPEILMAN RM A 19681001 10977161 SPEILMAN RM 3 N 10.3 1 R 0804442.85 GAITHMUN
c 0 14242 SPEILMAN RM A 19681001 11353748 SPEILMAN AZ MK RESET N 005.1 1 A 1501343.32 GAITHMUN
c 1 14242 SPEILMAN RM A 19681001 10147204 APPAL N 0.5 1 N 1973803.09 GAITHMUN *
c 1 14242 SPEILMAN RM 3 19680926 10147204 APPAL N 0.5 2 N 0000000.00 GAITHMUN *
c 1 14242 SPEILMAN RM 3 19680926 10977160 SPEILMAN RM A N 10.3 2 N 0630118.20 GAITHMUN
c 1 14242 SPEILMAN RM 3 19680926 10977163 DAVIS N 0.5 2 N 1621118.77 GAITHMUN
c 0 14242 SPEILMAN RM 3 19680926 11353748 SPEILMAN AZ MK RESET N 005.1 2 A 3153247.76 GAITHMUN
c 1 14242 SPEILMAN RM 3 19681001 10147204 APPAL N 0.5 1 N 0000000.00 GAITHMUN *
c 1 14242 SPEILMAN RM 3 19681001 10977160 SPEILMAN RM A N 10.3 1 N 0630114.80 GAITHMUN
c 1 14242 SPEILMAN RM 3 19681001 10977163 DAVIS N 0.5 1 N 1621118.51 GAITHMUN
c 0 14242 SPEILMAN RM 3 19681001 11353748 SPEILMAN AZ MK RESET N 005.1 1 A 3153249.40 GAITHMUN
c
c M 14242 APPAL 196810 11351573 APPAL RM 2 N 0.016 000020.737 GAITHMUN *
c M 14242 APPAL 196810 11351572 APPAL RM 1 N 0.016 000022.806 GAITHMUN *
c M 11766 APPAL 19580127 11351572 APPAL RM 1 N 0.016 000022.805 MHSHFBLT *
c M 11766 APPAL 19580127 11351573 APPAL RM 2 N 0.016 000020.742 MHSHFBLT *
c E 11766 APPAL 19580131 10137533 JERU N 0.061 002029.475 MHSHFBLT *
c S 14241 OCTIN 19681009 10147204 APPAL N 0.033 13309.832 SPOFFORD *
c S 14241 OCTIN 19681009 10147204 APPAL N 0.033 13309.836 SPOFFORD *
c S 14241 OCTIN 19681009 10147204 APPAL N 0.033 13309.840 SPOFFORD *
c S 14241 OCTIN 19681009 10147204 APPAL N 0.033 13309.841 SPOFFORD *
c S 14241 OCTIN 19681018 10147204 APPAL N 0.033 13309.817 SPOFFORD *
c S 14241 OCTIN 19681018 10147204 APPAL N 0.033 13309.820 SPOFFORD *
c S 14241 OCTIN 19681018 10147204 APPAL N 0.033 13309.823 SPOFFORD *
c S 14241 OCTIN 19681018 10147204 APPAL N 0.033 13309.833 SPOFFORD *
c S 14241 OCTIN RM A AMS 1968 19681009 10147204 APPAL N 0.033 13300.376 SPOFFORD *
c S 14241 OCTIN RM A AMS 1968 19681009 10147204 APPAL N 0.033 13300.378 SPOFFORD *
c S 14241 OCTIN RM A AMS 1968 19681009 10147204 APPAL N 0.033 13300.379 SPOFFORD *
c S 14241 OCTIN RM A AMS 1968 19681009 10147204 APPAL N 0.033 13300.384 SPOFFORD *
c S 14241 OCTIN RM A AMS 1968 19681018 10147204 APPAL N 0.033 13300.375 SPOFFORD *
c S 14241 OCTIN RM A AMS 1968 19681018 10147204 APPAL N 0.033 13300.376 SPOFFORD *
c S 14241 OCTIN RM A AMS 1968 19681018 10147204 APPAL N 0.033 13300.381 SPOFFORD *
c S 14241 OCTIN RM A AMS 1968 19681018 10147204 APPAL N 0.033 13300.384 SPOFFORD *
c S 14241 SPEILMAN RM A 19681031 10147204 APPAL N 0.034 16222.120 SPOFFORD *
c S 14241 SPEILMAN RM A 19681031 10147204 APPAL N 0.034 16222.120 SPOFFORD *
c S 14241 SPEILMAN RM A 19681031 10147204 APPAL N 0.034 16222.123 SPOFFORD *
c S 14241 SPEILMAN RM A 19681031 10147204 APPAL N 0.034 16222.136 SPOFFORD *
c S 14241 SPEILMAN RM A 19681101 10147204 APPAL N 0.034 16222.111 SPOFFORD *
c S 14241 SPEILMAN RM A 19681101 10147204 APPAL N 0.034 16222.127 SPOFFORD *
c S 14241 SPEILMAN RM A 19681101 10147204 APPAL N 0.034 16222.128 SPOFFORD *
c S 14241 SPEILMAN RM A 19681101 10147204 APPAL N 0.034 16222.138 SPOFFORD *
c S 14241 SPEILMAN RM 3 19681031 10147204 APPAL N 0.034 16235.026 SPOFFORD *
c S 14241 SPEILMAN RM 3 19681031 10147204 APPAL N 0.034 16235.028 SPOFFORD *
c S 14241 SPEILMAN RM 3 19681031 10147204 APPAL N 0.034 16235.031 SPOFFORD *
c S 14241 SPEILMAN RM 3 19681031 10147204 APPAL N 0.034 16235.032 SPOFFORD *
c S 14241 SPEILMAN RM 3 19681101 10147204 APPAL N 0.034 16235.034 SPOFFORD *
c S 14241 SPEILMAN RM 3 19681101 10147204 APPAL N 0.034 16235.036 SPOFFORD *
c S 14241 SPEILMAN RM 3 19681101 10147204 APPAL N 0.034 16235.038 SPOFFORD *
c S 14241 SPEILMAN RM 3 19681101 10147204 APPAL N 0.034 16235.044 SPOFFORD *
c z-A3858 APPAL 19680926 10976974 OCTIN N 1.4 1 S 3172300.77 A156
3) I don't remember where I read the actual specs, but the ideas of the narrow triangles ("A" stations"), astro positions every other station, etc were intriguing and helped me to understand what was necessary to achieve high accuracy in the days before GPS
?ÿ
@john-hamilton?ÿ John H. Thank you for the clarification on your post. I hope it did not take you too long to post all that.
I??m am glad you enjoyed Ryans presentation. He has done a lot of work developing a field ready system. I was part of the GEMS survey with him in AK last fall. I wasn??t part of the astronomy crew, that??s way past my bedtime. I was there to do the GNSS observations along the line. Weather is a big factor, it??s got to be clear. But the system works, that??s for sure.?ÿ
I use my T2 and T3 a lot. I used to do a lot of star shots. But I get about 3? with solar, so I haven??t done much night work in the past couple of years.
Z12, Opus, and T2 solar az and ZA is quite satisfying. Not much commercial application, but it??s a great way to keep your skills sharp.?ÿ
I use my T2 and T3 a lot. I used to do a lot of star shots. But I get about 3? with solar, so I haven??t done much night work in the past couple of years.
Z12, Opus, and T2 solar az and ZA is quite satisfying. Not much commercial application, but it??s a great way to keep your skills sharp.?ÿ
That's great. When I was doing solar observations about 20 years ago, I was using a 3" total station with a solar filter and got time from a handheld GPS receiver and used ephemeris data from Jerry Wahl's website (www.cadastral.com). I seemed to be able to get consistent 15" accuracy. Getting 3" accuracy from solar observations is very impressive.
I only did a Polaris observation one time, just to say I did it, and it wasn't rigorous so I don't really know what sort of accuracy potential I might have had with it. Polaris is not an easy star to sight without a right-angle optic. I know more of the stars now, so I might pick something a little easier to see if I were to do a night observation.
I did learn how to switch the reflector for the cross-hair illumination on and off in the T2 a few nights ago. Very ingenious.
I live in the Shenandoah valley, Hagerstown MD. There are several radio towers on the mountain ridges visible all across the valley. I occupied about 45 random points well scattered throughout the valley. ZA and astro azimuth on all.
I did specifically to locate the towers sufficiently accurate to have 1 second azimuth reliability of azimuth. The towers are about 25 mi apart in a nice triangle.
I prefer tropical stars over Polaris. Vertical angles less than 30?ø.
Solar azimuth has been routinely discounted. But with Xi Eta deflection and GPS timing so easily available I don??t think solar is any less accurate than tropical stars, and 40?ø vertical to Polaris is difficult.
And often I use the Z-XII??s camera event recording for UTC, and always correct to UT1 ?ÿ
it??s been a multi year muse. Several points I have many repeat observation. In Starnet azimuth global a priori error at 3.5? returns error factor of 1.2.?ÿ
