SMOS EADS CASA Espacio Payload Project Manager: interview with Andrés Borges
Since ESA elected EADS CASA Espacio as Prime Contractor for the MIRAS instrument, Andrés Borges has been in charge of consolidating the instrument design and leading an industrial consortium of European companies to develop and manufacture all the sub-systems and equipments of the instrument.
Borges graduated in Electrical Engineering from the University Polytechnic of Valencia, Spain, in 1989. After graduation, he worked at ESA as a Software Engineer, specialising in software development for space robotics.
In 1992, Borges joined EADS CASA Espacio in Madrid, Spain, where he worked on several space projects for six years as a Software and System Engineer. In 1998, he was appointed as the Project Manager of the MIRAS Demonstrator Project, a technology development project for SMOS, and he later continued as Project Manager throughout the development phases of the SMOS payload, MIRAS.
At present, he is the project manager of INGENIO, the first Spanish optical satellite. He completed his studies with a Master of Business Administration (MBA).
ESA: What does being the Espacio Payload Project Manager involve?
I have spent more than 10 years of my professional career working with SMOS. My company started working with the SMOS mission in 1996, mainly in the development of basic technologies. Later, with a solid background of instrument technology and operations, we were successful in getting SMOS selected as an Earth observation mission.
Since then I have contributed to the development of the instrument mainly from the managerial point of view, although I started as a system engineer. During these years and with the help of ESA and the Spanish administration (CDTI), we have consolidated the instrument design and technologies. We have also created a very motivated industrial consortium to develop and manufacture all the sub-systems and equipments of the instrument.
ESA: Soil moisture is a very difficult variable to estimate with several factors, such as soil type and vegetation cover, contributing to the variability in the soil moisture estimates. How have you overcome this challenge?
The information on soil moisture properties (the same is applicable to ocean salinity) is contained in the microwave emission from the soil captured by the SMOS instrument, MIRAS. The principle is that the variation of the electromagnetic properties of the soil depends on the water content. Then, the soil emits an electromagnetic energy that is detected by the instrument’s sensors to make the brightness temperature of the surface.
The intensity of the electromagnetic energy is very low but fortunately the frequency emissions is at L-band, 1413 MHz, a frequency protected for astronomy which ensures no interference from man-made emissions.
By measuring the power emitted by Earth in this frequency and by doing a very complex post processing of the data retrieved by MIRAS, the soil moisture maps of Earth can be made. The algorithms are very complex and take into account many variables as perturbations and contamination effects.
The challenge is to design and manufacture the sensors and the data chain to fulfil the radiometric sensitivity and accuracy requirements. Otherwise the quality of the instrument data will not be good enough for the scientists to convert them into soil moisture maps of Earth.
ESA: How is the MIRAS instrument able to measure both soil moisture and ocean salinity?
MIRAS is a microwave radiometer based on a Synthetic Aperture antenna with interferometry.
In fact, Synthetic Aperture Radiometry was developed in the 1950s to obtain high resolution radio images and was applied initially to Radio Astronomy. MIRAS is using this principle but for Earth observation. Indeed, the most important contribution of MIRAS is the application of this technology and theory to Earth observation.
Traditionally the radiometers were based on real and large antennas with a mechanical scan of-the-field view to synthesise the ground pixels. The pixel resolution is linked to the antenna size, so the larger the antenna the better the resolution.
The advantage of the MIRAS concept is the good pixel resolution achieved by using a set of small individual antennas. MIRAS can also be scaled up. By increasing the number of antennas, the resolution improves. The result is a more affordable instrument that maintains a very good performance.
ESA: MIRAS is the first instrument to apply the techniques of ‘aperture synthesis’ and ‘interferometry’ in space. What does this mean and what technical challenges had to be overcome to make these concepts work?
MIRAS consists on a set of antennas, all of them with the same field of view. The signal captured by every antenna is cross-correlated with the signal captured by the other antennas. The result is like having a large antenna and this antenna is scanning the field of view electronically to synthesise the pixels.
The MIRAS challenge is to develop the technologies and to implement them in the instrument chain, from antenna to correlator, including the very sensitive receivers, the internal calibration means, a thermal control design to keep the receivers temperature in orbit within less than 5ºC range or the signal transmission using optical fibres to avoid interferences and samplings drifts.
The MIRAS development is the result of 13 years of research and development work done by the European industry.
ESA: What role will EADS CASA Espacio play once SMOS is operational?
EADS CASA Espacio is very committed with SMOS. We started years ago in SMOS contributing in the development of the technology needed for this satellite. After that, we worked with our industrial partners, the users, CDTI (the Spanish delegation at ESA) and ESA in the appointment of SMOS as one Earth Observation Mission and once achieved we have intensively contributed to the development of the SMOS instrument. Certainly, once the satellite is in orbit and begins its operational life, we will follow its behaviour and functionality.
We are interested in helping the ground segment operators to command the satellite and the users to validate the operational modes and performances of the instrument as well as the data provided.
We want to contribute to the success of the mission and, as we have been involved from the beginning, we know how the instrument should behave and how we need to command it during the first phase up until the successful validation of its commissioning.
Moreover, EADS CASA Espacio still has the tools used in the development of the instrument and these tools can be used to analyse the data sent to the satellite to see if the instrument is behaving as expected.
ESA: Where will you be for launch?
My plan is to be at ESA’s ground station in Spain (VILSPA), where the MIRAS team will control and monitor the instrument during the launch and early operations phase (LEOP) and the in-orbit calibration (IOC) phase. I want to see with my own eyes how the instrument behaves once in orbit and to help the ground segment operators in the commissioning phase.
This is one in a series of interviews with a few of the key people involved in the SMOS mission. Please check back, as the list will be added to over the coming weeks.