Value chain · CLM-0978
In plain terms
In 1979 Boeing wrote down where the timing errors in the transmitter would come from. Most of the allowance, about six of the seven degrees, went to the cables and waveguides carrying the reference around the structure; the electronics at each tube got about one degree each.
The claim as recorded
Boeing's 1979 Phase II budget for random phase error in a three-layer distribution allocates, in degrees: phase jitter 1.13, transmitter noise at 30 dB carrier-to-noise 0.36, conjugators 1.04, lines 6.22, diplexers 2.56, transmitters 1.60, differential Doppler 0.18 - RSS 7.09 degrees, peak 13.09, "Phase Error Caused Loss: 1.53%". The cable and waveguide lines are the dominant term, larger than conjugators, diplexers and transmitters combined. The systematic pointing budget on the same table is 6.44 x 10^-3 degrees RSS with one pilot station and 3.22 x 10^-4 with three, dominated by atmospheric and ionospheric differential refraction.
Evidence behind this: T3-contractor final report, an error budget stated as goals by component.
Scope and limits
GOALS FOR A DESIGN, NOT A MEASURED SYSTEM, AND FOR A THREE-LAYER TREE. How each per-source delta becomes its line entry (1.04 from 0.6, 6.22 from 2.54) is not shown on the table. The 1.53 per cent loss uses the report's own loss relation, not stated on this page.
What it assumes
Goals, not measurements: the per-source deltas in brackets are the assumed unit errors from which each line is built.
Where it comes from
Table 7.1-2 from the render: "Random Errors for 3 Layers Phase Distribution, Phase Errors (Deg): Phase Jitter 1.13; Transmitter Noise (C/N = 30 db) .36; Conjugators (delta_c = .6 deg) 1.04; Lines (delta_l = 2.54 deg) 6.22; Diplexers (delta_d = 1.81 deg) 2.56; Transmitters (delta_p = 1.6 deg) 1.60; Differential Doppler (v_d = 6.25 m/s) .18; Peak: 13.09, RSS: 7.09; Phase Error Caused Loss: 1.53%." Recomputed: the seven entries sum to 13.09 and their root sum of squares is 7.09. Systematic errors (pointing, degrees), one pilot station and three: Doppler 1.43e-6 and 7.15e-8; aberration 19.3e-6 and 9.65e-8; ionospheric differential 2.35e-3 and 1.17e-4; atmospheric differential 6.00e-3 and 3.00e-4; RSS 6.44e-3 and 3.221e-4; pointing loss RSS 0.92 and 0.46 per cent.
Basis: degrees rms of phase error per source, three-layer phase distribution; per cent loss
Related records
- Answers question
- QST-013 not published in this release
Cite this
energyaperture.com/c/clm-0978
CLM-0978, Energy Aperture, as of 1979.
Connected records
Other published records linked to this one. A list, not a judgement.