License GEOBATHY




 
1 - NO NEED for field data, nor for atmospheric correction
2 - this is demonstrated in this website, using a variety of hyper/multi spectral data
 
Requirements are
1 - homogeneous water body and atmosphere
2 - some coverage of optically deep water
3 - some coverage of dry land
 
Problems are
1 - the precision on estimated depth is found wanting, because the noise-equivalent change in radiance  of accessible data is too high for shallow water column correction work 
2 - radiance data should be preprocessed by the provider at level 1 in order to improve S/N ratio
3 - exponential decay: the deeper/darker the bottom, the poorer the performances
 
So
I keep digging
until suitable data
become available
 

The following is a certified translation of the license granted by IFREMER to Yann MOREL in 1999.
see the conditions

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LICENSE FOR USE OF GEOBATHY SOFTWARE
Ref. IFREMER Nb. 99/12 13282

BETWEEN

The INSTITUT FRANCAIS DE RECHERCHES POUR L'EXPLOITATION DE LA MER, public institute with industrial and commercial status, SIRET No 330 715 368 00297, hereinafter referred to as IFREMER, headquartered at 155, Rue Jean-Jacques Rousseau, 92138, ISSY-LES-MOULINEAUX Cedex, France, and represented by its Chief Executive Officer or his proxy,

AND

M. Yann MOREL, natural person, whose address is pk 13.500, Côté Mer, PUNAAUIA, BP 4616, Papeete, French Polynesia, hereinafter referred to as the Licensee

Hereinafter referred to together as the Parties.

RECITALS:

The Licensee has developed, within the framework of his activities at IFREMER, software for the modeling of shallow water bottoms using multispectral images, hereinafter referred to as the Software.

Pursuant to article L. 113-9 of the Copyright Code, IFREMER is the sole holder of proprietary rights for the exploitation of the Software.

IT HAS BEEN AGREED AS FOLLOWS:

ARTICLE 1. - PURPOSE

1.1. The purpose of this license contract is the granting by IFREMER to the Licensee, of the right to use and modify the Software, subject to the terms and conditions set out hereunder.

1.2. A description of the Software is attached to the present contract.

ARTICLE 2. - GRANTING OF RIGHTS TO EXPLOIT THE SOFTWARE

2.1. IFREMER grants the Licensee, free of charge and non-exclusively, the right to use the Software to provide services and carry out work for third parties in exchange for payment.

2.2. IFREMER also grants the Licensee the right to adapt and modify the Software in order to make it compatible with other image processing systems or other operating systems, and/or to improve its functionalities.

It is agreed that the Licensee will be exclusively entitled to the rights of exploitation of any software programs derived from the Software which he will have developed as per the preceding paragraph and will therefore be able to exploit them, whether directly or indirectly, for his sole profit.

2.3. The rights to use and adapt the Software are granted on a worldwide basis and for the duration of the copyright in France.

ARTICLE 3. - TRANSMISSION OF THE SOFTWARE

3.1. IFREMER will communicate to the Licensee the source codes for the Software, and all existing documentation, as of the date of signature of this contract by the parties.


3.2. The licensee shall not mention or refer to the term "IFREMER" when using the Software or software derived from it, whether orally or in writing.

ARTICLE 4. - CONFORMITY OF THE SOFTWARE

4.1. IFREMER pledges to supply the Software to the Licensee, as is, subject to its good operability, without warranty.

In no case shall IFREMER guarantee the aptitude of the Software to perform any particular task.

4.2. The Licensee shall implement the basic software and acquire the relevant licenses, and configure the appropriate equipment for exploitation of the Software.

4.3. IFREMER shall not be deemed responsible for any prejudice or damage, direct or indirect, that the Licensee might suffer due to use of the Software.

4.4. The Licensee shall not be entitled, by way of this contract, to the improvements or later versions of the Software, which IFREMER may develop.

ARTICLE 5. - INFRINGEMENT

5.1 IFREMER authorizes the Licensee to take legal action for infringement, at his own risk, against anyone copying or counterfeiting all or part of the Software.

5.2. The Licensee waives recourse to any warranty action against IFREMER, should a third party take legal action against the Licensee, alleging that the Software breaches intellectual or proprietary rights held by that party according to French law in force.

ARTICLE 6.- DURATION. TERMINATION

This contract is valid for the duration of the copyright protection in France, from April 1, 1999 on.

However each of the parties shall have the right to terminate this contract in the case of non-fulfillment by the other party of its contracted commitments, one month after formal notification for performance has been sent to the defaulting party and has remained to no avail.

ARTICLE 7.- DISPUTES

Any dispute with respect to the validity or performance of this contract shall be submitted to the Tribunal de Grande Instance de Nanterre (District court of Nanterre, France).

ARTICLE 8.- APPENDIX

Appendix 1: Description of the Software.

On behalf of IFREMER

Signed in Brest, 7 thof April 1999

Pierre DAVID

Chief Executive Officer

On behalf of the Licensee

Yann MOREL

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APPENDIX


DESCRIPTION OF THE GEOBATHY SOFTWARE

NATURE AND FUNCTIONALITIES

The GEOBATHY software for "bathymetric modeling of shallow bottoms using multispectral imagery" is based on simplified equations of the radiative transfer of light through water found in manuals. Maritorena, Morel and Gentilly* have recently confirmed that these equations can be safely applied to radiance data sets obtained using remote sensing techniques. It is also based on optical properties of marine waters described by Jerlov in his reference book "Marine Optics" (1976), which was first published in 1963.

Under these conditions, and provided that part of the multispectral imagery represents dry land, the software provides complete calibration of calculations, thus obtaining an estimate of depth and reflectance of the shallow bottom, without using any field data.

The GEOBATHY software has been successfully tested, using a databank of multispectral SPOT satellite images representing a great number of islands and atolls in French Polynesia, and sparse field data (existing maps, data from SHOM).

TECHNICAL SPECIFICATIONS

The GEOBATHY software is written in C programming language.

It is run on a computing platform under the UNIX operating system.

It is based on the image format and functionalities of the GEOimage image processing system, marketed by the French firm GEOimage, France.

It is exclusively adapted to processing the three channels of the multispectral image of the satellite SPOT, i.e., the XS1 (green at 550 nm), XS2 (red at 650 nm) and XS3 (near infrared at 850 nm) bands.

Its execution results in one image of the computed water depth and one image of the computed bottom reflectance, both in the GEOimage image format.

ACCURACY FOR WATER DEPTH

According to Philpot**, and under the best imaging conditions (i.e., clear skies, absence of wind and clouds, sun high in the sky, near-vertical viewing), the error calculation for the most frequent cases of SPOT or Landsat satellite images (8-bit coded images), should provide accuracy for the computed depth on the order of 10% of the actual depth.

ACCURACY FOR BOTTOM REFLECTANCE

There is no known, published reference which can be used as a specification. However, it can be mentioned that, according to the equations used (those used by Philpot** and Maritorena et al.*), accuracy for bottom reflectance will necessarily be an exponential function of accuracy for depth of that bottom.

REFERENCES

* S. MARITORENA, A. MOREL and B. GENTILLY, 1994, "Diffuse Reflectance of Oceanic Waters: Influence of Water Depth and Bottom Albedo". Limnology and Oceanography, vol. 39, No 7, pp. 1689-1703.
** W. D. PHILPOT, 1989, "Bathymetry Mapping with Passive Multispectral Imagery". Applied Optics, vol. 28, No 8, pp. 1569-1578.