D3A Mount Design
Specifications
Concept
The concrete block has dimensions of 74 cm × 74 cm × 152 cm (or 29" × 29" × 152") and a mass of 2 tonnes.
In this concept the elevation angle would be continuously adjustable over a zenith angle range of ±30° using a manually-actuated jack screw.
The zenith angle could be measured with an electronic inclinometer such as this one which has an accuracy better than an arcmin.
Alignment Procedure
- Use standard surveying techniques to place the concrete blocks.
- Align elevation axis on each dish so that relative pointing is within 1 arcmin. Could use laser tracker for this step.
- Attach dishes to mounts and verify 1 arcmin relative alignment using laser tracker measurements of targets on the rim of each dish.
- Final radiometric alignment by comparing drift scans as a source passes through the beam of each dish. From time differences between dishes as a source passes through the peak and/or first nulls, make fine adjustments to azimuth. (See table in D3aTestPlan for arcmin/sec for different declinations.)
Results
-- WayneGretzsky - 2019-04-05