## 7 Conclusions and Future Work  
The mission measurement concept of _TWVC_ is constructed based on radio sensing of the atmosphere. A system design that measures atmospheric water vapor is proposed, the requirements and specifications are determined, and system interfaces and integration are done. A GNU Radio-based transceiver that has the capability of transmitting and receiving SS signal is also implemented. The SS-BPSK has shown good reception and demodulation of SS-transmitted signals with and without delay. All the transmitted data in 1 s intervals are perfectly recovered, and two satellite payloads are utilized to demonstrate the ISL network successfully considering one orbital plane. This research can be further developed to demonstrate the full success criteria of the _TWVC_ mission based on a constellation of more than two satellites in motion and in different orbital planes of the LEO. If that is achieved, 3D mapping of atmospheric water vapor or _TEC_ can be perfectly deduced. Moreover, this paper only considered the ISL network configuration; however, a combination of fixed and mobile ground stations together with ISL networks can also be implemented to ensure a robust system that determines the 3D mapping of _TWVC_ over a wider area. The test results demonstrate the possibility of reconfiguring the frequency onboard the satellite with the proposed algorithms. The determined duration of frequency translation is measured within 1 s as was proposed. The time delay estimation method with the current configuration has also been successful, and it can be recommended as an effective technique for _TWVC_ or _TEC_ calculations from the signal propagation time delay. For future studies, sweeping through much lower available meteorological frequency bands could be considered as a way to improve mission measurement accuracy. This is because lower frequency bands are more influenced by atmospheric geophysical parameters. However, multiple antennas calibrated for the selected frequencies must be implemented. Also, possible phase delays and errors that may occur in orbit due to the positioning accuracy of the GPS or frequency reconfigurations shall be scrutinized as part of the next objectives. Clock jittering is also successfully removed to ensure the incoming and outgoing signals are not distorted with instrument and clock offsets. This improves mission accuracy within 35 us when a 10 MHz atomic clock such GPS clock is used. Low orbital attitude, lower frequency bands, and a constellation of more than 1000 satellites can give this method improved accuracy and high spatiotemporal resolutions compared to conventional techniques. Based on these results, the proposed system demonstrated that it is feasible to conduct atmospheric measurements using the radio signals onboard small satellites. The acquired data will be incorporated into the global atmospheric databases of geophysical parameters for climate and weather prediction models. Participating and contributing to ongoing research initiatives are necessary for integrating obtained data into global atmospheric databases for climate and weather prediction models, in addition to adherence to the accepted standards and data sharing agreements. The 3D-mapped data of the _TWVC_ will be aligned with standardized formats, units, and metadata acknowledged by the atmospheric research community. Additionally, partnership with organizations that specialize in collecting and distributing atmospheric data will be considered. To guarantee seamless integration of the acquired data with existing global atmospheric databases, data quality control will be conducted by institutions that specialize in data evaluation and validation. Institutions and researchers involved in atmospheric modelling and research will be granted open access to the acquired data. Finally, the institute will hold workshops and forums that bring together researchers, modelers, and data providers to discuss integration challenges, strategies, and opportunities.