Ground penetrating radar survey
A ground penetrating radar (GPR) was used for a characterization of the “martian” subsoil. This is a non-invasive, sub-surface imaging technique for, among others, geological applications. In the GPR scanning process electromagnetic energy (in the form of radio waves) is pulsed into the substrate via an antenna at a certain frequency (100 Mhz in this case). These pulses bounce off structures into the soil (new layers, ect). They are then captured by a receiver antenna. This technique is interesting for Mars because the material is light and easy to use compared to other geophysical techniques. The output of this kind of survey is a radargram where different layers of soil of buried structures can be visible.
During the simulation, the following material (provided by Exploration Instruments) was used:
- Shielded monostatic antenna 100 Mhz, model 3207
- Control unit SIR4000
- Survey wheel 12’’
Three surveys were done:
- A field of 500 m² near the quarry (518500 4255500)
- A field of 15000 m² 2km northern the station (518500 4251500)
- A field of 10000 m² 1km southern the station (0519938 4247631)
Although a post-processing is still necessary for the results (the “radargram”), preliminary observations can be done: Two different layers were identified, northern the station and it seems that the layers are quite uniform with no cavities. Thanks to the numerous geophysical profiles that were collected, 3D-mapping will be set.
After these two weeks of survey, it would be interesting to analyse other fields near the station with other type of antenna (especially a bistatic antenna or antenna that pluses electromagnetic energy at a higher frequency [200 Mhz or 400 Mhz]). Morever, other interesting areas were found during the EVA’s.
