Search

The Remote sensing and Interference detector with radiome-Try and vegetation Analysis (RITA Payload) [1] is a development of the UPC NanoSat Lab, aimed at Earth Observation (EO). It is one of the winners of the Second IEEE GRSS Student Grand Challenge, and will fly on-board AlainSat-1, a 3U CubeSat developed by the National Space Science and Technology Center (NSSTC) of the United Arab Emirates.RITA hosts three experiments. An L-band microwave radiometer (MWR) will gather data of soil moisture and sea ice thickness and concentration, aided with a Radio-frequency Interference (RFI) detection algorithm. A LoRa transceiver will perform on-demand execution of the EO experiments [2]. Finally, a Near-Infrared (NIR) Hyperspectral Camera will gather data for vegetation monitoring, agriculture applications, hydrology and coastal and inland waters mapping, among others [3].This work is focused on the calibration and validation of the Hyperspectral imager, at optical, electronic and spectral levels, as well as in the verification of its performance to measure Normalized Difference Vegetation Index (NDVI)., This project is supported and funded by the IEEE Geoscience and Remote Sensing Society (GRSS), as one of the winners of the 2nd IEEE GRSS Student Grand Challenge. It is also part of the project ”GENESIS: GNSS Environmental and Societal Missions – Subproject UPC”, Grant PID2021-126436OB-C21 funded by the Ministerio de Ciencia e Investigación (MCIN) / Agencia Estatal de Investigación (AEI) / 10.13039/501100011033 and EU FEDER “Una manera de hacer Europa., Peer Reviewed, Postprint (author's final draft)

The 3Cat-4 mission is a 1-unit CubeSat platform that serves as a technology demonstrator and educational platform for students at Universitat Politècnica de Catalunya (UPC). Promoted by the UPC Nanosatellite and Payload Laboratory (UPC NanoSatLab), the most notable subsystems that innovate in the nanosatellite scenario are (1) the Flexible Microwave Payload - 1 (FMPL-1) [1], a cost-effective payload to execute Global Navigation Satellite System Reflectometry (GNSS-R), and L-band microwave radiometry experiments using a commercial off-the-shelf (COTS) software-defined radio (SDR) and (2) the Nadir Antenna Deployment Subsystem (NADS) [2], an in-orbit deployable high-directivity antenna used by Earth Observation (EO) payloads. This paper presents the findings of the 3Cat-4 mission during Phase D, the qualification and production phase of the project. Since the publication of the first introductory work for this mission in 2019[3], several sections of the subsystems have been redesigned and upgraded to correct previous design flaws or to meet new requirements. In addition, this paper addresses the educational perspective of this mission, analyzing its performance and usefulness in the aforementioned subject.

The Remote sensing and Interference detector with radiomeTry and vegetation Analysis (RITA) is one of the Remote Sensing payloads selected as winners of the 2nd GRSS Student Grand Challenge in 2019, to fly on board of the 3U AlainSat-1. This CubeSat is being developed by the National Space Science and Technology Center (NSSTC), United Arab Emirates University. RITA has been designed as an academic mission, which brings together students from different backgrounds in a joint effort to apply very distinct sensors in an Earth Observation mission, fusing their results to obtain higher-accuracy measurements. The main payload used in RITA is a Total Power Radiometer such as the one on board the FSSCat mission. With these radiometric measurements, soil moisture and ice thickness will be obtained. To better characterize the extensive Radio-Frequency Interferences received by EO satellites in protected bands, several RFI Detection and Classification algorithms will be included to generate a worldwide map of RFI. As a novel addition to the 3Cat family of satellites and payloads, a hyper-spectral camera with 25 bands ranging from 600 to 975 nm will be used to obtain several indexes related to vegetation. By linking these measurements with the soil moisture obtained from the MWR, pixel downscaling can be attempted. Finally, a custom- developed LoRa transceiver will be included to provide a multi-level approach to in-situ sensors: On-demand executions of the other payloads will be able to be triggered from ground sensors if necessary, as well as simple reception of other measurements that will complement the ones obtained on the satellite. The antennas for both the MWR and the LoRa experiments have been developed in-house, and will span the entirety of one of the 3U sides of the satellite. In this work, the latest development advances will be presented, together with an updated system overview and information about the operations that will be conducted. Results obtained from the