The PCW (Polar Communications and Weather) mission is a dual satellite mission with each satellite in a highly eccentric orbit with apogee ~42,000 km and a period (to be decided) in the 12–24 hour range to deliver continuous communications and meteorological data over the Arctic and environs. Such as satellite duo can give 24×7 coverage over the Arctic. The operational meteorological instrument is a 21-channel spectral imager similar to the Advanced Baseline Imager (ABI). The PHEOS-WCA (weather, climate and air quality) mission is intended as an atmospheric science complement to the operational PCW mission. The target PHEOS-WCA instrument package considered optimal to meet the full suite of science team objectives consists of FTS and UVS imaging sounders with viewing range of ~4.5° or a Field of Regard (FoR) ~ 3400×3400 km2 from near apogee. The goal for the spatial resolution at apogee of each imaging sounder is 10×10 km2 or better and the goal for the image repeat time is targeted at ~2 hours or better. The FTS has 4 bands that span the MIR and NIR with a spectral resolution of 0.25 cm−1. They should provide vertical tropospheric profiles of temperature and water vapour in addition to partial columns of many other gases of interest for air quality. The two NIR bands target columns of CO2, CH4 and aerosol optical depth (OD). The UVS is an imaging spectrometer that covers the spectral range of 280–650 nm with 0.9 nm resolution and targets the tropospheric column densities of O3 and NO2 and several other Air Quality (AQ) gases as well the Aerosol Index (AI).
The Canadian Space Agency issued, in 2007, a Request for Proposals on The Atmospheric Processes on Climate and its
Changes (APOCC). Innovative mission concepts were selected on the basis that they: Lead to new scientific
understanding of atmospheric processes that regulate Earth's climate; Address questions of particular importance for
northern latitudes; Build on Canada's experience and capacity in atmospheric science; Complement/ be synergistic with
planned international missions. With the concept studies finished, the foreseen way forward is to issue support initiatives
to develop those reformulated concepts that combine the most promising ideas in several affordable instrument
contributions and Canadian spacecraft missions. This paper presents the rationale for the continued implementation of
the APOCC initiative.
The need for High Data Rate (HDR) communications and Near Real Time (NRT) meteorological information for the
Canadian North led by the Canadian Space Agency (CSA) to propose the Polar Communication and Weather (PCW)
mission to facilitate sovereignty operations in the Canadian North by providing reliable communications and increase the
ability to model and predict environmental changes occurring in the northern regions. Rapid coverage of the full Earth disk
from the highly elliptical PCW orbit requires that the scanning pattern of the Meteorological Payload be well understood.
To that effort, we carried out a study to simulate and then analyze the scan mirror geometry and error sources. Multiple scan
patterns and mirror geometry (gimbaled, two mirrors) have been investigated to guide the system design to minimize mirror
displacements (duty cycle) and image distortions due to viewing geometry and Earth curvature. Results from simulations
and comparative evaluations of both mirror geometry and scanning patterns (gimbaled, two mirrors) are provided with
interpretations and conclusions.
The Canadian Space Agency (CSA) is developing a pre-operational spaceborne Hyperspectral Environment and Resource Observer (HERO). HERO will be a Canadian optical Earth observation mission that will address the stewardship of natural resources for sustainable development within Canada and globally. To deal with the challenge of extremely high data rate and the huge data volume generated onboard, CSA has developed two near lossless data compression techniques for use onboard a satellite. CSA is planning to place a data compressor onboard HERO using these techniques to reduce the requirement for onboard storage and to better match the available downlink capacity. Anomalies in the raw hyperspectral data can be caused by detector and instrument defects. This work focuses on anomalies that are caused by dead detector elements, frozen detector elements, overresponsive detector elements and saturation. This paper addresses the effect of these anomalies in raw hyperspectral imagery on data compression. The outcome of this work will help to decide whether or not an onboard data preprocessing to remove these anomalies is required before compression. Hyperspectral datacubes acquired using two hyperspectral sensors were tested. Statistical measures were used to evaluate the data compression performance with or without removing the anomalies. The effect of anomalies on compressed data was also evaluated using a remote sensing application.