Difference between revisions of "New site and tripod setup description"

From GeodesyLab
Jump to: navigation, search
m (maxk put the finishing touches on it. Thanks, Ronni!)
 
Line 22: Line 22:
 
<tr>
 
<tr>
 
   <td>'''3.'''</td>
 
   <td>'''3.'''</td>
−
   <td>fasten tribrach onto middle of the tripod head.</td>
+
   <td>fasten tribrach only onto middle of the tripod head.</td>
 
   <td>place entrire tribrach/optical plumb on tripod.</td>
 
   <td>place entrire tribrach/optical plumb on tripod.</td>
 
</tr>
 
</tr>
Line 39: Line 39:
 
<tr>
 
<tr>
 
   <td>'''5.'''</td>
 
   <td>'''5.'''</td>
−
   <td>With leg clamp loose, stomp tripod feet firmly in soil (stabelize with rocks if necessary)</td>
+
   <td>With leg clamp loose, stomp tripod feet firmly in soil (stabilize with rocks if necessary)</td>
 
   <td>same.</td>
 
   <td>same.</td>
 
</tr>
 
</tr>
Line 52: Line 52:
 
   <td>'''7.'''</td>
 
   <td>'''7.'''</td>
 
   <td>attach optical plumb to tribrach and focus 2 things:<br/>
 
   <td>attach optical plumb to tribrach and focus 2 things:<br/>
−
1. focus large knob on marker<br/>
+
1. turn large knob to focus on marker<br/>
−
2. focus small knob for black ring sign.<br/>
+
2. turn small knob to focus black ring sights.<br/>
 
both should be sharp and in focus.
 
both should be sharp and in focus.
 
   </td>
 
   </td>
Line 61: Line 61:
 
<tr>
 
<tr>
 
   <td>'''8.'''</td>
 
   <td>'''8.'''</td>
−
   <td>loosen tribrach using the hollow screw and the steer the dot in the sight over to within 1 cm of center punch on marker.
+
   <td>using tribrach knobs steer the dot in the sight over to within 1 cm of center punch on marker.
 
   </td>
 
   </td>
 
   <td>Take your nail w/ pre-existing punch mark or small drill hole in head. One person pounds nail into ground while other person guides its placement - centered under the leveled tripod.</td>
 
   <td>Take your nail w/ pre-existing punch mark or small drill hole in head. One person pounds nail into ground while other person guides its placement - centered under the leveled tripod.</td>
Line 68: Line 68:
 
<tr>
 
<tr>
 
   <td>'''9.'''</td>
 
   <td>'''9.'''</td>
−
   <td>re-level the tribrach bulls-eye by adjusting the leg length. </td>
+
   <td>re-level the tribrach bulls-eye by adjusting the tripod leg length. </td>
 
   <td>celebrate the new benchmark.</td>
 
   <td>celebrate the new benchmark.</td>
 
</tr>
 
</tr>
Line 91: Line 91:
 
<tr>
 
<tr>
 
   <td>'''12.'''</td>
 
   <td>'''12.'''</td>
−
   <td>rotate optical plumb by 180° ti see if long bubble is correctly balanced. If not then split the difference back towards the center so the bubble is off by the same number of ticks (e.g. to the left) at 180° opposite orientations of optical plumb.<br/><br/>
+
   <td>rotate optical plumb by 180° to see if long bubble is correctly balanced. If not then split the difference back towards the center so the bubble is off by the same number of ticks (e.g. to the left) at 180° opposite orientations of optical plumb.<br/><br/>
−
For example a badly balanced bubble might be level wehn it is 2 ticks off to the left (as you face the bubble).
+
For example a badly balanced bubble might be level when it is 2 ticks off to the left (as you face the bubble).
 
<br/>
 
<br/>
 
</td>
 
</td>
Line 100: Line 100:
 
<tr>
 
<tr>
 
   <td>'''13.'''</td>
 
   <td>'''13.'''</td>
−
   <td>Once the tribrach is finely leveled, you are not neccessarily still centered on the marker. You must loosen the hollow screw just slightly enough to allow for translation without rotation of the tribrach (slide it on the  
+
   <td>Once the tribrach is finely leveled, you are not necessarily still centered on the marker. You must loosen the hollow screw just slightly enough to allow for translation without rotation of the tribrach (slide it on the  
 
tripod head with braced hands) while looking through sight so that dot in scope is centered on punch mark.
 
tripod head with braced hands) while looking through sight so that dot in scope is centered on punch mark.
 
<br/>
 
<br/>
Line 119: Line 119:
 
<tr>
 
<tr>
 
   <td>'''16.'''</td>
 
   <td>'''16.'''</td>
−
   <td colspan="2" align="center">Orient true north (if no magn. declenation is given, use 25°E for Alaska) and screw lock adapter to keep it from rotating</td>
+
   <td colspan="2" align="center">Orient true north (if no magn. declenation is given, use 25°E for Alaska) and screw-lock adapter to keep it from rotating</td>
 
</tr>
 
</tr>
  
 
<tr>
 
<tr>
 
   <td>'''17.'''</td>
 
   <td>'''17.'''</td>
−
   <td colspan="2" align="center">measure out slant height with height stick to underside inner egde of 3 notches. Read stick from opposite undersite of tripod. Record heights on logsheet to nearest half mm. All three measurements should be within 1 or 2mm of each other. (if not, try to find the problem by starting over at any of the above steps, check brass element for dirt, check antenna for being bent etc.)
+
   <td colspan="2" align="center">measure antenna slant height with height stick to underside inner egde of 3 notches. Read stick from opposite underside of tripod. Record heights on logsheet to nearest half mm. All three measurements should be within 1 or 2mm of each other. (if not, try to find the problem by starting over at any of the above steps, check brass element for dirt, check antenna for being bent etc.)
 
</td>
 
</td>
 
</tr>
 
</tr>
Line 130: Line 130:
 
<tr>
 
<tr>
 
   <td>'''18.'''</td>
 
   <td>'''18.'''</td>
−
   <td colspan="2" align="center">connect receiver power and antenna cables. All lights flash during boot, green light should come on. If not, press (green) power button.
+
   <td colspan="2" align="center">connect receiver power and antenna cables. All lights flash during bootup, green light should come on. If not, press (green) power button.
 
   </td>
 
   </td>
 
</tr>
 
</tr>
Line 136: Line 136:
 
<tr>
 
<tr>
 
   <td>'''19.'''</td>
 
   <td>'''19.'''</td>
−
   <td colspan="2" align="center">Receiver should track satellites in a minute (quick red blinking) to show slow red flash. Good.
+
   <td colspan="2" align="center">Receiver should track satellites in a minute (quick red blinking) to slow red flash. Good.
 
   </td>
 
   </td>
 
</tr>
 
</tr>
 
<tr>
 
<tr>
 
   <td>'''20.'''</td>
 
   <td>'''20.'''</td>
−
   <td colspan="2" align="center">orange logging light should be on / blink slowly; if not press blue button to start logging. Wrap everything and store it safely so that neither bear, moose nor tides can carry it away. done. Find next site and continue with step 1 :)
+
   <td colspan="2" align="center">orange logging light should come on / blink slowly; if not press blue button to start logging. Wrap/bag everything and store it safely so that neither bear, moose nor tides can carry it away. done. Find next site and continue with step 1 :)
 
   </td>
 
   </td>
 
</tr>
 
</tr>
  
 
</table>
 
</table>

Latest revision as of 02:17, 11 July 2008

This a description Max Kaufman had written up; Yuning and Ronni volunteered as guinea pigs for the pre-existing site part.

  pre-existing site new site
1. extend tripod legs equally to chest height. same.
2. adjust tribrach knobs to reference line. same.
3. fasten tribrach only onto middle of the tripod head. place entrire tribrach/optical plumb on tripod.
4. use tribrach to position tripod correctly over marker by satisfying the following 3 conditions:

1. bulls eye level bubble is level
2. you can look down through hollow screw and see marker
3. all tripod feet are on ground.
(Note: this is the most tricky, but if carefully done most rewarding step for everything that follows.)

spread tripod feet out @ 1 m separation and locate them so that tribrach is level.
5. With leg clamp loose, stomp tripod feet firmly in soil (stabilize with rocks if necessary) same.
6. roughly level tribrach again by adjusting tripod leg length. same.
7. attach optical plumb to tribrach and focus 2 things:

1. turn large knob to focus on marker
2. turn small knob to focus black ring sights.
both should be sharp and in focus.

same.
8. using tribrach knobs steer the dot in the sight over to within 1 cm of center punch on marker. Take your nail w/ pre-existing punch mark or small drill hole in head. One person pounds nail into ground while other person guides its placement - centered under the leveled tripod.
9. re-level the tribrach bulls-eye by adjusting the tripod leg length. celebrate the new benchmark.
10. confirm still centered near the punch mark in view. celebrate a little more.
11. fine tune the leveling of long level bubble on optical plummet:

1. align bubble between 2 tribrach knobs and level it by turning knobs equally and in opposite directions.
2. rotate optical plumb so long level bubble is at 90° to previous measurement.
3. use the 3rd knob on tribrach to level it.
Note: note directions on opt. plumb for bubble adjustment!

same.
12. rotate optical plumb by 180° to see if long bubble is correctly balanced. If not then split the difference back towards the center so the bubble is off by the same number of ticks (e.g. to the left) at 180° opposite orientations of optical plumb.

For example a badly balanced bubble might be level when it is 2 ticks off to the left (as you face the bubble).

same.
13. Once the tribrach is finely leveled, you are not necessarily still centered on the marker. You must loosen the hollow screw just slightly enough to allow for translation without rotation of the tribrach (slide it on the

tripod head with braced hands) while looking through sight so that dot in scope is centered on punch mark.

same.
14. Repeat steps 11 to 13 until level and centered
15. Now you are level and centered. Screw lock optical plumb to prevent it rotating. Fasten antenna to top of optical plumb with brass adapter.
16. Orient true north (if no magn. declenation is given, use 25°E for Alaska) and screw-lock adapter to keep it from rotating
17. measure antenna slant height with height stick to underside inner egde of 3 notches. Read stick from opposite underside of tripod. Record heights on logsheet to nearest half mm. All three measurements should be within 1 or 2mm of each other. (if not, try to find the problem by starting over at any of the above steps, check brass element for dirt, check antenna for being bent etc.)
18. connect receiver power and antenna cables. All lights flash during bootup, green light should come on. If not, press (green) power button.
19. Receiver should track satellites in a minute (quick red blinking) to slow red flash. Good.
20. orange logging light should come on / blink slowly; if not press blue button to start logging. Wrap/bag everything and store it safely so that neither bear, moose nor tides can carry it away. done. Find next site and continue with step 1 :)
Retrieved from "http://gps.alaska.edu/internal/index.php?title=New_site_and_tripod_setup_description&oldid=1592"