**Appendix B**

This section presents the sensors that have been considered in the survey with their corresponding references.The sensors are assessed in terms mass, power consumption, data rate, and orbit altitude.


**Table A4.** Survey of microwave imagers (MWI).

The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements; Light gray: Micro-platform; Gray: Mini-Platform; *<sup>a</sup>* 3 arm size; *<sup>b</sup>* Resolution range for standard products.

**Table A5.** Survey of microwave sounders (MWS).


The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: Very light gray: Nano-platform; Light gray: Micro-platform; Gray: Mini-Platform; *<sup>a</sup>* This instrument has two antennas with different apertures.


#### **Table A6.** Survey of GNSS-R instruments.

The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: Very light gray: Nano-platform; Light gray: Micro-platform; Gray: Mini-Platform; *<sup>a</sup>* Antenna mass doesn't include.



The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: Very light gray: Nano-platform; Light gray: Micro-platform.

**Table A8.** Survey of optical radiometer instruments: multispectral and hyperspectral.

variables and sea surface variables. *c*

Instrument affordable for Observation of land surface (e.g., vegetation), marine biology (e.g., ocean color), and

cloud/aerosol.



The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: Very light gray: Nano-platform; Light gray: Micro-platform; gray: mini-platform; *a* Instrument affordable for cloud analysis, aerosol inference, land surface variables and sea surface variables.


## **Table A10.** Survey of Radar Altimeter instruments.

The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: light gray: micro-platform; gray: mini-platform. \* Interferometry; *<sup>a</sup>* Spatial resolution over land; *<sup>b</sup>* Spatial resolution over ocean.


#### **Table A11.** Survey of scatterometer instruments.

The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: gray: mini-platform; black: large-platform.

10 (Ku-band)



The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: light gray: micro-platform; gray: mini-platform. *<sup>a</sup>* Along track resolution (SAR mode).



The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: Gray: mini-platform; black: large-platform.


**Table A14.** Survey of the lidar instruments.

The background color in the table indicates the type of platform suitable for the instrument according to the power and mass requirements: gray: mini-platform; black: large-platform.
