Please have a look at these researchgate links.

https://www.researchgate.net/publication/261277274_Exploiting_ten_years_of_MERIS_data_over_land_surfaces

https://www.researchgate.net/publication/260138225_Continuous_Change_Detection_and_Classification_of_Land_Cover_Using_All_Available_Landsat_Data

Conference Paper Exploiting ten years of MERIS data over land surfaces

Article Continuous Change Detection and Classification of Land Cover...

Dear Muhammad,

Your query appears to be ambiguous: it is not clear whether you wish to identify sources of satellite reflectance data or providers of field measurements to be compared with remote sensing data you already have.

Arvind provided you with some useful pointers to satellite data, and there are many more options available. On the other hand, it may be that you are actually looking for spectral reflectance measurements acquired in situ. Please clarify this point, as well as the ultimate purpose of collecting such data.

Also, to elicit more relevant comments and suggestions, please specify the location and size of the area of interest (or does it not matter where such data have been collected?), and indicate when, over which period, and at which temporal frequency such remote sensing and field measurements should be available for your purpose.

Lastly, please note that while multispectral reflectance data acquired from satellite platforms are often freely available from major Space Agencies, field measurements may not be: these are obtained by individual investigators, using their limited financial resources. In fact, there is no single or coordinated organization to collect and distribute such data on a global scale because field data are likely to be of interest only to a rather small group of researchers working on that site.

Regards, Michel.

Dear Michel,

I apologise for not asking a clear question. I am developing an atmospheric correction method using Landsat dataset and later, will also test on MODIS and VIIRS datasets. Therefore, I am looking for spectral reflectance measurements acquired in-situ using hand-held multi spectrometer. The location and size of area, and temporal frequency of the measurements don't matter. I understand that reflectance measurements are not freely available and acquired by individual investigators using their limited financial resources. So, it will be highly appreciated and acknowledged if someone provide me surface reflectance measurements acquired in-situ.

Thank you!

Dear Arvind,

Thanks for your input.

Regards, Bilal.

Hello muhammad

working with hand-held multi spectrometer. It is the most ideal method that someone could select to investigate the reality of atmospheric correction methods.

Doing this measurement by yourself could have a great effect on improving results.

But with an approach of the optimal use of existing facilities, Comparison of classification accuracy _resulted from other atmospheric correction methods_ by your final output could be an alternative method. 

Best Regards, Sayed Javad

Dear Sayed Javad,

Many thanks for your input. Yes, It is an alternative method but accuracy of other atmospheric correction methods over a specific region is questionable. 

Regards, Bilal

Hell Dr Bilal here i have send a some in-situ data that we have measure by using a ASD Spectroradiometer for a different  land cover so please see the attach file.

thanks