Introduction
A brief technical summary of the Thoth Technology 46 m antenna on the site of the Algonquin Radio Observatory (ARO) in the Province of Ontario, Canada is provided.
Location
The antenna is located at 45 deg 57 min 19.8 sec latitude, 281 deg 55 min 37.0 sec east longitude, 260.4 m elevation.
Antenna Performance
The following table presents the estimated performance information for the 46 m antenna at ARO.
Table 1 Antenna Performance, 46 m Antenna at ARO
| Aperture efficiency |
0.42 at 10 GHz (full surface); 0.29 at 22 GHz (inner solid surface) |
| Area gain |
74 dBi at 10 GHz |
| Effective aperture gain |
70 dBi at 10 GHz, 69.1 dBi at X-band, 68.6 dBi at S-band |
The Antenna Structure
The following table presents information on the structure of the 46 m antenna.
Table 2 Antenna Structure, 11 m Antenna at ARO
| Antenna diameter |
150 feet (45.8 m) |
| Focal length |
Prime focus 60 feet (18.3 m) |
| Parabolic reflector |
Inner surface of 0.635 cm (1/4 in) thick steel plate, 36.6 m (120 feet) in diameter. Outer surface of panels of galvanized steel square mesh of 1 mm diameter wire with 10 mm spacing, 4.55 m (15 feet) in radius width all round. The solid surface is adjustable with one adjuster screw at every 4-corner intersection of the steel plates |
| Focii |
Both prime focus and Gregorian capability with 10 foot (3 m) diameter elliptical subreflector |
| Focal ratio |
F/D = 0.4 for full surface and F/D = 0.5 for inner solid surface |
| Feed support |
Tetrapod feed legs supporting prime focus aerial cabin. Prime focus cabin: cylindrical 2.5 m diameter by 3.7 m length |
| Gregorian focus |
Located in the Vertex Room: cylindrical 5.8 m diameter by 6.4 length |
| Surface accuracy |
rms departure from best fitting paraboloid = 0.85 mm. Maximum departure from best fitting paraboloid = ±0.32 mm (inner solid surface) = ±0.64 mm (outer mesh surface) |
Antenna Operations and Control
The following table presents operations and control information for the 46 m antenna at ARO.
Table 3 Operations and Control, 46 m antenna at ARO
| Altitude/Azimuth antenna mount |
Computer controlled pointing |
| Azimuth range of motion |
±215 degrees in Azimuth centred on an Azimuth of 112.5 degrees West of North |
| Elevation range of motion |
102 degrees (-5 degrees to 97 degrees) in elevation |
| Maximum operating wind velocity |
80 kmhr-1 (50 mph) |
| Extreme operational temperature range |
-46oC to +40oC |
| Azimuth slewing |
Variable in rate up to 24 degrees per minute |
| Elevation slewing |
Variable in rate up to 10 degrees per minute ascending and up to 15 degrees per minute descending |
| Pointing accuracy |
Current performance ±20 arc sec. With enhanced pointing model in place ±10 arc sec |