Recently I ran into a project using an instrument known as ground penetrating radar and imaging instrument. There appears to be several manufacturers that provide such capability. There was a discussion on finding hidden objects in this forum. Here is an example -
There are many different types of antennas available, and measurements could be 5-30 or more meters depth. It was originally developed for evaluation of roads and bridge foundations, but has been adapted by research folks in archeology. I have seen a research paper or two using it for an excavation in Ireland.
The instrument costs around $120,000 and it is likely that companies that provide inspection services for infrastructure may have one, perhaps not for the depth one may need. A low frequency antenna is about $4000, and one can cover a decent area in a single day. It does require a trained person to interpret the signal. A 3-D mapping software linked to a GPS system can also be done. If this is augmented with conductivity and ultrasonic measurements, one can reduce false signals.
Our old temples have, I believe, many undiscovered characteristics. A non-invasive method might be a good way to go about examining temple premises without disturbing regular temple schedule.
Regards, Raj Mutharasan
The GSSI SIR-30 is a multi-channel GPR data acquisition unit that when combined with the requested antenna can be used to investigate road structures, concrete and materials integrity analysis, both deep and shallow geological investigations, archaeology and cultural preservation investigation, railroad bed inspections, mining applications, bridge deck inspections, environmental applications for subsurface exploration and remediation, shallow seismicity, geotechnical investigation including landslide prediction, prevention, and remediation and many other combined applications across curriculum. The GPR coupled with an integrated computer running GSSI�s RADAN 7 GPR for data acquisition and portability makes acquisition and processing of data in remote terrain possible. Collection of 3D subsurface images using this system is simple, integrated and completed using a Windows-based system allowing for a variety of users at many different levels of understanding. The SIR-30 provides reliable GPR data and can be used in flexible situations when vehicle mounted or on a cart system. The SIR�30 is compatible with all requested antennas, can use up to two antenna channels at one time which allows for all research areas to use the GPR effectively to obtain high quality data. In general the lower mega-hertz antenna provides deeper subsurface data. For more shallow applications such as concrete inspection or void analysis a 400 MHz antenna is necessary while a 200 MHz antenna would be more appropriate for geotechnical or shallow seismic investigations. For existing free-standing infrastructure air horn applications are standard. We propose to acquire the following antenna which can be combined for inter-disciplinary uses: 200 MHz, 270 MHz, 400, 900 MHz and 2 GHz air horn. The SIR- 30 can combine hardware antenna inputs from 2 antenna channels which will allow for deep investigations without compromising detailed surface analysis. As research needs change and extend beyond the current necessities, acquisition of more antennas is possible and seamless with the use of GSSI�s SIR-30. To facility infrastructure investigation the SIR-3000 BridgeScan system is requested to facility existing faculty research in civil engineering structural bridge design. The SIR-3000 is a selfsupporting, robust, portable acquisition system created for existing infrastructure investigation and is capable of being used by itself or in combination with the SIR-30. It is a robust, application-specific use that requires only a single operator for investigations. The SIR-3000 incorporates advanced signal processing and display capability for �in-the-field� 3D imaging and is interchangeable with all GSSI antennas, making it a flexible option for multi-application users.
if we are thinking about these technologies in the context of unearthing hidden structures........... why is that many of these lost structures are in mounds, sometimes 40 50 feet in height actually debunks the theory that archeology was about the underground structures and while we are on it are metal detectors banned in india?
I don’t think there is a ban on metal detectors. To build something to sense traces of it in the granite clutter in buried structures might require a bigger setup.
Lets explore and see if we can build a prototype as outlined by sash and with guidance from Raj mutharasan and other specialists in the fields. We can approach any of the Eng colleges within our contact range to do this as a final year project with some funding / support from us.
My daughter also studied image progressing ( but more from bio-medical imaging side , but can be leveraged )in her BE final this year. Will ask her to explore more on this.
Raj /Sash : can we put to gether a small doc on what can be done as a small prototype using existing material , as a college final year project.
Imagine such small ventures on the maligai medus ( with folk lore ) scattered over kumbakonam and surroundings and small breaks it can produce.
Looking forward to more suggestions / ideas on this from the seniors in this field.
This is a specialized instrument and image processing software is a critical and a central enabling technology. I would not recommend developing one. Instead buy the technology. Raj Mutharasan
I posted a message that GPR was used in Ayodhya and the canadian company's report was submitted to the court. That post has not appeared. Is it anything to do with the new policy?sampath
In this case where it is better to use existing tech, can we as a group explore a project where we rent it for a short period and target on probable old chola temple / palace buried in mounds , based on the folklore around the place.
This will be our contribution towards rediscovering history, in addition to discussing and exploring historical literature.
One way to do what you are thinking about is to develop a research project - meaning an investigation of a target area or site. If an instrument is available in one of the institutions in India, one try to seek their support and involvement. If that is not the case, one can write a research proposal in collaboration with researchers at IIT Madras or Guindy Engineering College or others, State Department of Archeology (if the site is under their supervision) and possibly MCC (Tambaram) or Tamil University (Tanjavur) for the instrument as well as the funding for the expedition/measurements. It seems to me like a worthwhile project. Raj Mutharasan
More important than either hardware or software is expertise.
These images are complicated to manipulate, even when you have the right software (which isn't such a problem for me - I can at least help with access). The trouble is getting someone who can actually make a useful image out of it.
If there's a serious proposal, I can try to dig up some contacts and see if it goes anywhere.
That is encouraging. Probably the difficult part from software perspective is signal processing. The software would need to manage the launch of the waveform, and collect noisy return signal adjusting for depth and travel time, process the resulting spectrum to create an image. There are many parameters - both in waveform analysis as well as return signal time and gain; recall velocity is a function of the medium (a bit of guess work as iteration as to be incorporated) and thus associating return signal with a particular depth plane becomes an adjustment in calculation.
I am certain this is doable with expertise available at the engineering colleges. But time to a reasonable working model would take time, I am afraid quite some time. It might be easier to lease or rent such an equipment as it gets to data collection quicker. Interpretation of the constructed images would still need to be done.