The Landsat programme is a joint USGS and NASA-led enterprise for Earth observation that represents the world's longest running system of satellites for moderate-resolution optical remote sensing for land, coastal areas and shallow waters. 

Satellite details:

Landsat-7 continues the goal of the Landsat programme to image repetitively Earth's land and coastal areas with the aim of monitoring changes to those areas over time. The satellite continues to provide data continuity for the Thematic Mapper aboard Landsat-4 and 5, utilising an enhanced version of the instrument.  

The Enhanced Thematic Mapper Plus (ETM+) is the main instrument on board Landsat-7 and has been operational since 1999. It provides 30 m resolution for visible (VIS), near infrared (NIR) and shortwave infrared (SWIR) as well as 60 m resolution for thermal infrared. Moreover, it adds 15 m resolution panchromatic band (PAN). 

Product  TypeInstrumentSpatial RangeTemporal RangeType of Access
ETM–GTC-1P(*) ET Europe September 1999 – December 2003IAD (Immediately available data) 
ETM-L1G ET Europe September 1999 – November 2015September 1999 – November 2015 
ETM-L1GT ET Europe September 1999 – January 2017 September 1999 – January 2017 
ETM-L1G ETEurope September 1999 – January 2017September 1999 – January 2017