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We present a simple way of coding and compressing the data on board the Planck instruments (HFI and LFI) to address the problem of the on board data reduction. This is a critical issue in the Planck mission. The total information that can be downloaded to Earth is severely limited by the telemetry allocation. This limitation could reduce the amount of diagnostics sent on the stability of the radiometers and, as a consequence, curb the final sensitivity of the CMB anisotropy maps. Our proposal to address this problem consists in taking differences of consecutive circles at a given sky pointing. To a good approximation, these differences are independent of the external signal, and are dominated by thermal (white) instrumental noise. Using simulations and analytical predictions we show that high compression rates, $c_r simeq 10$, can be obtained with minor or zero loss of CMB sensitivity. Possible effects of digital distortion are also analized. The proposed scheme allows for flexibility to optimize the relation with other critical aspects of the mission. Thus, this study constitutes an important step towards a more realistic modeling of the final sensitivity of the CMB temperature anisotropy maps.
Data on board the future PLANCK Low Frequency Instrument (LFI), to measure the Cosmic Microwave Background (CMB) anisotropies, consist of $N$ differential temperature measurements, expanding a range of values we shall call $R$. Preliminary studies an
Powerful constraints on theories can already be inferred from existing CMB anisotropy data. But performing an exact analysis of available data is a complicated task and may become prohibitively so for upcoming experiments with gtrsim10^4 pixels. We p
We present simulations of different scanning strategies for the Planck satellite. We review the properties of slow- and fast-precession strategies in terms of uniformity of the integration time on the sky, the presence of low-redundancy areas, the pr
Suggestions have been made that the microwave background observed by COBE and WMAP and dubbed Cosmic Microwave Background (CMB) may have an origin within our own Galaxy or Earth. To consider the signal that may be correlated with Earth, a correlate-b
The standard inflationary model presents a simple scenario within which the homogeneity, isotropy and flatness of the universe appear as natural outcomes and, in addition, fluctuations in the energy density are originated during the inflationary phas