Software downloaded from myworld.leica
geosystems.com 10dec19. There are older versions of this software
on the leica usb stick software directory.
This came with the tm50 package on
nov19. It includes lots of leica doc beyond what we
link to directory (local only access)
200708: theodolite elevation angles for various
200129: signal strength from ao9 and platform
The tm50 has a limited elevation angle range
before you need to install a different eyepiece for large
When a new eyepiece is installed, there is a counterweight that needs to be installed on the front of the optics to balance the extra weight.
The eyepiece should probably not be changed once a measurement has started since changing it my move the theodolite a bit.
The picture shows the two additional
eyepieces available for the tm50 (.png)
||chin hits keyboard around elevation =29deg.
||extra eyepiece we got with the dec2019 order
since the eyepiece swivels it can also be used to look horizontally
beyond 66 degrees it hits the side of the theodolite structure.
Can not be used to measure dome at 0deg za from ao9
||eyepiece sent jun20
Can go all the way to 90 deg.
If you want to look horizontally you the eyepiece will be pointing straight up.
Is needed to measure the dome at za=0 from ao9.
I used the 08may2004 sokia theodolite measurement of the
secondary to get an idea of the elevation angles need when
measuring the secondary from the theodolite stand on the edge of
The plot shows the elevation angle of the theodolite for the 51 secondary targets that were used (.ps) (.pdf)
One of the benefits of the tm50 is the motor drive. You can
position to a target before adjusting and measuring. When either
of the extra eyepieces are installed there is a danger that the
motor could move to a position where the eyepiece would hit the
body of the theodolite.
We are contemplating using a p40/p50 to scan the primary dish surface. This will depend on the distance and the reflectivity of the surface. We do not know the reflectivity of the surface (for the laser frequency used by the p40/50). An idea was to used the tm50 to measure the signal strength as a function of slope distance from ao9 and the platform . This would give us an idea of how fast the return signal falls off (and maybe even the reflectivity :).
To measure the signal strength:
On 29jan20 the tm50 was mounted on ao9. The signal strength was measured from the primary surface using reflectorless mode. The tm50 was pointed around az=340 degrees and the elevation was changed from around 0 to 17 degrees (close to ao9 up to the edge of the reflector). The signal strength was recorded for each measurement.Plots were made of the signal strength vs slope distance as well as angle to the surface normal (.ps) (.pdf)
On 06feb20 the tm50 was mounted on the
platform on the outside stairwell of the gregorian dome.
The dome was as za=11 degrees. The tm50 was about 9 meters from za=0, and 2.4 below the rolling surface of the dome.
The azimuth was pointing at az=90 deg (east). points were taken from the edge of the dish down to about za = 10 degrees.
The plots show the tm50
signal strength from the platform (.ps) (.pdf)