Please refer one of my research paper below uploaded in RG for more information. "Reclamation of Land and Improve Water Productivity of Jaffna Peninsula of Northern Sri Lanka by Improving the Water Quality of the Lagoons"

with regards-Siva

What is the scale of your domain? For studies of chlorophyll in coastal waters using bands with 300 m, 500 m, 1000 m this is already consider a fairly high-resolution approach. As you said, most studies have used MODIS and MERIS, and also SeaWIFS for this purpose. If using MODIS be aware that MODIS-Aqua is a really good option but MODIS-Terra has serious issues in the blue bands by which is not recommended. Also, the classic algorithms for chla (OC3, OC4) are not a really good option for coastal waters with turbid conditions (case 2 waters), and thus there are many recent studies modifying these algorithms at local scales in order to measure chla properly. In case 2 waters as many coastal regions, the chla signal is commonly masked with the CDOM and sediments signatures, so modifying the algorithms is a good idea. This has been done using MODIS-Aqua and MERIS mostly. Now, for an adequate "monitoring" you need an adequate delta t (time interval), so using a low temporal resolution sensor is not a good idea. Most energetic processes in coastal regions are within the synoptic band, and using a 16 days time interval would not let you resolve these signals. A basic concept; according to the Nyquist frequency you are not able to resolve frequencies higher than 1/2dt. In other words you will not be able to resolve any signal with periods shorter than 32 days. Aliasing would be another big issue to deal with...

One of the coastal systems with a best monitoring approach is the Chesapeake Bay, check the papers and how MODIS and MERIS have been used in this context.

Last comment, nowadays there is another sensor with bands at 750 m spatial resolution, this is a sensor similar to SeaWIFS but with higher spatial resolution: the sensor is VIIRS.

Hi Majid,

A few ideas below on the Total Suspended Matter or suspended sediment concentration area you raise:

1. It may be that you’ve identified a key methodological gap here! You should suggest to the world space agencies that the need for remotely-sensed data at the appropriate band - at both high spatial and temporal resolution - should be addressed quickly! You could double-check with NASA people directly too (e.g. Dr Chris Kidd of NASA, formerly of University of Birmingham, UK, who is very knowledgeable in this area).

2. Another suggestion is to make direct contact with the relevant groups around the world, from a really detailed search of the literature on Google Scholar, Scopus or ISI Web of Science etc. An example could be the B. Nechad, K.G. Ruddick and Y. Park group at the Royal Belgian Institute for Natural Sciences (RBINS), Management Unit of North Sea Mathematical Model (MUMM), 100, Gulledelle 1200 Brussels, Belgium (e.g. they published a paper in 2010 entitled ‘Calibration and validation of a generic multisensor algorithm for mapping of total suspended matter in turbid waters’ (Remote Sensing of Environment, Vol 114, Issue 4, 15 April 2010, Pages 854–866).

3. You could also find out more about the Visible Infrared Imaging Radiometer Suite (VIIRS), and its future plans, as mentioned by Gonzalo at Oregon State above.

4. If you need data at really small spatial scales, though, have you considered a direct instrumental approach based on in-situ monitoring of turbidity e.g. using an array of unattended OBS sensors or turbidity meters connected to dataloggers programmed to take measurements automatically at 1 minute, 1 hour, 1 day, 1 week frequency, as appropriate? Or fixing turbidimetric or OBS instrumentation to boats at the required depth, and cruising detailed transects around Hong Kong waters?

5. Whether you use remote sensing or in-situ monitoring, however, the stronger studies tend to develop robust calibrations between (a) actual suspended sediment concentrations and either (b) remotely-sensed radiometric data, or (c) the in-situ light-scattering data from instruments - either Turbidimetric measurements (i.e. attenuation of signal through the sample) or Nephelometric data (i.e. measurement of the light scattering directly, often at 90 degrees).

6. Such calibrations are not easy to produce. These relationships also vary over space with changes in the particle size distribution of the suspended sediment (e.g. around coastlines and along estuaries and down rivers) which strongly influences IR scattering for a given suspended sediment concentration. Hence, these calibrations can also change over time, as sediment sources and properties switch between storms, fluvial floods, tides and currents etc.

I discuss the last couple of points in the attached 2005 paper, and in others on my profile (e.g. 2006 Science of the Total Environment), and there are many more references out there by other groups there too.

Good luck!

Damian Lawler

Here's the 2006 paper mentioned above (a fluvial example), but it shows the dynamics of complex turbidity (~~ suspended sediment concentration) changes and time leads or lags over several storm events in an urban river.

Thanks Gonzalo Saldias and Damian Lawler, your comments are very useful for me.

Dear Majid! you may also fiind some useful references in my paper published about Chlorophyll a in WHISPERS, 2013

Thanks Hassan, can you please share the link of your paper.

You can refer to the following publication. It has so much information about variations in water properties during a red tide. I used MODIS imagery in this research. 

Conference Paper Investigation the Behavior of MODIS Ocean Color Products und...

i can help in this study

my research about using remote sensing in water quality