Optical quantum communication utilizing satellite platforms has the potential to extend the reach of quantum key distribution (QKD) from terrestrial limits of ∼200 km to global scales. We have developed a thorough numerical simulation using realistic simulated orbits and incorporating the effects of pointing error, diffraction, atmosphere and telescope design, to obtain estimates of the loss and background noise which a satellite-based system would experience. Combining with quantum optics simulations of sources and detection, we determine the length of secure key for QKD, as well as entanglement visibility and achievable distances for fundamental experiments. We analyze the performance of a low Earth orbit (LEO) satellite for downlink and uplink scenarios of the quantum optical signals. We argue that the advantages of locating the quantum source on the ground justify a greater scientific interest in an uplink as compared to a downlink. An uplink with a ground transmitter of at least 25 cm diameter and a 30 cm receiver telescope on the satellite could be used to successfully perform QKD multiple times per week with either an entangled photon source or with a weak coherent pulse source, as well as perform long-distance Bell tests and quantum teleportation. Our model helps to resolve important design considerations such as operating wavelength, type and specifications of sources and detectors, telescope designs, specific orbits and ground station locations, in view of anticipated overall system performance.2. Photons undergo a rotation to simulate imperfectly aligned polarization optics, and appropriate losses are applied to the quantum channel.3. Photons are measured resulting in count rate statistics, with added noise accounting for background light and detector dark counts. A realistic detector efficiency is used.4. These statistics are taken in various loss and background count rate regimes to assess optimal and typical expected performance.

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Corrigendum: A comprehensive design and performance analysis of low Earth orbit satellite quantum communication (2013 New J. Phys. 15 023006) Abstract. Optical quantum communication utilizing satellite platforms has the potential to extend the reach of quantum key distribution (QKD) from terrestrial limits of ∼200 km to global scales. We have developed a thorough numerical simulation using realistic simulated orbits and incorporating the effects of pointing error, diffraction, atmosphere and telescope design, to obtain estimates of the loss and background noise which a satellite-based system would experience. Combining with quantum optics simulations of sources and detection, we determine the length of secure key for QKD, as well as entanglement visibility and achievable distances for fundamental experiments. We analyse the performance of a low Earth orbit satellite for downlink and uplink scenarios of the quantum optical signals. We argue that the advantages of locating the quantum source on the ground justify a greater scientific interest in an uplink as compared to a downlink. An uplink with a ground transmitter of at least 25 cm diameter and a 30 cm receiver telescope on the satellite could be used to successfully perform QKD multiple times per week with either 4

AIM-North is a proposed satellite mission that would provide observations of unprecedented frequency and density for monitoring northern greenhouse gases (GHGs), air quality (AQ) and vegetation. AIM-North would consist of two satellites in a highly elliptical orbit formation, observing over land from $40 N to 80 N multiple times per day. Each satellite would carry a near-infrared to shortwave infrared imaging spectrometer for CO 2 , CH 4 , and CO, and an ultraviolet-visible imaging spectrometer for air quality. Both instruments would measure solar-induced fluorescence from vegetation. A cloud imager would make near-real-time observations, which could inform the pointing of the other instruments to focus only on the clearest regions. Multiple geostationary (GEO) AQ and GHG satellites are planned for the 2020s, but they will lack coverage of northern regions like the Arctic. AIM-North would address this gap with quasi-geostationary observations of the North and overlap with GEO coverage to facilitate intercomparison and fusion of these datasets. The resulting data would improve our ability to forecast northern air quality and quantify fluxes of GHG and AQ species from forests, permafrost, biomass burning and anthropogenic activity, furthering our scientific understanding of these processes and supporting environmental policy. R ESUM E AIM-North est une proposition de mission satellitaire visant a acqu erir des observations de l'h emisph ere nord a une fr equence et une densit e sans pr ec edent pour le suivi des gaz a effets de serre (GES), de la qualit e de l'air (QA) et de la v eg etation. AIM-North serait constitu ee de deux satellites plac es dans une orbite hautement elliptique permettant d'observer les surfaces situ ees entre 40 N et 80 N a plusieurs reprises au cours d'une journ ee. Chaque satellite transporterait un spectrom etre imageur op erant dans le proche infrarouge et l'infrarouge de courte longueur d'onde pour la mesure du CO 2 , CH 4 et CO, ainsi qu'un spectrom etre imageur op erant dans l'ultraviolet et le visible pour mesurer la qualit e de l'air. Ces deux instruments mesureraient aussi la fluorescence de la v eg etation induite par le soleil. La d etection des nuages en temps quasi-r eel permettrait de pointer les satellites sur les r egions ARTICLE HISTORYles moins ennuag ees. De multiples satellites g eostationnaires (GEO) pour la mesure de la QA et des GES sont pr evus pour la d ecennie 2020 mais ils ne couvriront pas les r egions les plus nordiques. AIM-North pallierait a ce manque et chevaucherait la couverture des satellites GEO, facilitant ainsi l'inter-comparaison de divers jeux de donn ees. Ces donn ees am elioreraient notre capacit e a pr evoir la QA des r egions nordiques et a quantifier les flux de GES et de QA provenant des milieux naturels et des activit es anthropiques, approfondissant notre compr ehension de ces processus et appuyant les politiques environnementales.

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