Provide an overview of the trade being evaluated, including its objectives and scope. Describe the context in which the tradeoffs are being considered and the decision-making process involved.
The parameter being evaluated in this trade is the slit width. Slit width is, as the name suggests, the width of the slit, which is an integral component of the payload responsible for determining how much light is let into the system. Larger slit width increases throughput but decreases optical resolution. This is due to the larger slit width increasing the optical power available for analysis in exchange for increasing the minimum difference in wavelength that can be resolved.
Identify the key criteria that will be used to evaluate and compare the different options being considered and how they will be weighed against one another. These criteria might include factors such as cost, performance, schedule, risk, and other relevant considerations.
There are many parameters that are affected by slit width. The primary ones are signal-to-noise ratio, spatial resolution, and spectral resolution. Other parameters that are affected include field of view, diffraction efficiency, and diffraction angle. The criteria for the parameters listed above are as follows.
Present a summary of the options being considered, along with their key characteristics and potential impacts. This might include information on costs, performance, schedule, risk, and other relevant factors.
Slits are available in a wide range of widths, ranging from 5 µm up to a maximum of 800 µm, and are typically between 1 mm and 2 mm in height, with a 1 mm height being the standard.
Also, it is important to note that one the slit is selected, it is permanently mounted, so it is difficult and costly to install a new one.
Compare and contrast the different options, highlighting the tradeoffs and challenges associated with each one. Evaluate the tradeoffs qualitatively and/or quantitatively that are required in order to achieve the desired objectives, and consider using tables or graphs to visually compare the options.
https://docs.google.com/spreadsheets/d/1jDxFkQcEjNeIFitOFyfM40F-0KgUTBhYNsgtCXl0Vm0/edit#gid=0
Looking at the values tabulated and the criteria, there are a few glaring observations. The spectral resolution is completely fine regardless of the slit width chosen. However, there are major problems with the spatial resolution and the SNR. the SNR is incredibly low, regardless of the slit width chosen, as an increase in slit width is associated with approximately a linear change in SNR. In regards to the spatial resolution, the instantaneous optical resolution is a little greater than the criteria set. However, when the integration time and the velocity of the CubeSat are taken into consideration, the resulting spatial resolution is much greater.
Provide recommendation(s) for next steps based on the findings of the tradeoff analysis. This might include a recommendation for a preferred option.
My primary recommendations are to first, increase the slit height to around 7mm which will increase swath width and SNR by a factor of 7. Given that we have already chosen the sensor, there isn’t too much to be done about the spatial resolution. If we increase the focal length, then we can decrease the spatial resolution at the cost of lower SNR. But given that SNR is so low already, I would hesitate to change it.