# A New Orbiting Deployable System for Small Satellite Observations for Ecology and Earth Observation
## 5 Radiometric Model as Tool for DORA Feasibility Study  
In this paper, we have presented a selection of study cases that are not exhaustive of all the possible marine, atmospheric, and oceanographic research topics, but they have been selected for being quite wide-ranging to carry out the feasibility study of the DORA project. In Table 3, we summarize the state-of-the-art of the presented study cases, which will highlight how new space missions, such as the one studied within the DORA project, can be of great benefit for their investigation and progress. Indeed, current remote sensing data are only partially available because of the high costs of the large satellite data acquisition and/or the still limited use of small satellites. \begin{table}
\begin{tabular}{c c c c c} \hline
**ID** & **Scientific Area** & **Goals** & **State-of-the-Art** & **What We Need** \\ \hline \multirow{6}{*}{_A1_} & & & Large satellites (e.g., ESA Sentinel, NOAA/NASA POESS, or EUMESAT MeUp programs) and & \(\bullet\) & Having the payload on a constellation of small satellites allows for a short revisiting time, critical to study real-time evolution of natural and anthropogenic events \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\ \hline \multirow{6}{*}{_A2_} & & High resolution continuous monitoring of polynyas dynamics to study the evolution of the seasonal ice production & MODIS onboard Aqua EOS has a short revisiting time, but a low spatial resolution (1 km) & A short revisiting time provided by a constellation is associated with higher resolution to investigate the small-scale variability that characterizes the ice-water border \\ \hline \multirow{6}{*}{_A3_} & & & Available data are not at resolutions of space and time needed to have a comprehensive monitoring of the sea state and altimetry dynamics and of coastal natural phenomena & Monitor narrower regions, allowing the acquisition of data at higher spatial resolution (few hundred meters), in various spectral ranges, on a daily basis, allowing for instance to track the evolution of pollutant spillage \\ \hline \multirow{6}{*}{_A4_} & & & & \\  & & & & \\  & & & & \\  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \hline \multirow{6}{*}{_A5_} & & & In many regions, such as the Mediterranean basin, & \\  & & hot-spot: measuring vertical precipitation profiles in this area can be of essential relevance for capturing the entire development process of a thunderstorm clouds and, therefore, to reduce their impacts & & Data with spatial and temporal resolutions good enough for a continuous and real-time characterization of fast-changing vertical structure of convective cells originated during extreme rainfall in the Mediterranean region \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \hline \end{tabular}
\end{table} 
Table 3: Summary of the study cases presented in Section 3. The forth column reports the current available data to study the specific research case, whereas the last one shows what it is still missing for a complete understanding of the related topics. Generally, for all the cases considered here, the remote sensing system should include instrumentation operating in the spectral range from VIS to NIR and in MW range, and on a global coverage, in order to accurately investigate and monitor the terrestrial environment. Such a system might be launched on a small satellite (mass \(\leq\) 100 kg), operating on a circular polar orbit, with an altitude of \(\sim\)400 to \(\sim\)800 km (LEO), resulting in an orbital speed of \(\sim\)7.5 km/s, which corresponds to a 6.91 km/s ground speed. The orbit should be also heliosynchronous, with an orbital period of about 100 min, i.e., about 15 orbits in one day, and equatorial passes at \(\sim\)10:00 \(\div\) 14:00 local time.