1. PLATFORMS & SENSORS Platform:
the vehicle carrying the remote sensing device – e.g. ground, airborne, spaceborne
Sensor:        
the remote sensing device recording wavelengths of energy e.g. camera, scanner

2. EARLY PLATFORMS & SENSORS
Birds, Kites, Balloons, Planes, with camera

3. 1. Satellite orbits “Sun-synchronous” “Geostationary”
Land monitoring e.g. Weather satellites
~ 700 km altitude ~ 30,000 km altitude
Spacebook -

4. Satellite orbits
Geostationary / geosynchronous : 36,000 km above the equator, stays vertically above the same spot, rotates with earth - weather images, communications, e.g. GOES (Geostat. Operational Env. Satellite)
Geostationary satellites capture a (~rectangular) scene,

5. Sun-synchronous satellites: km altitude, rotate at ~81-82 degree angle to equator: imagery ~ the same local time each day (~10.30am)
Landsat path: earthnow

6. 2. Scanner types
Whiskbroom (mirror/ cross-track): a small number of sensitive diodes for each band sweep perpendicular to the path or swath, centred directly under the platform, i.e. at 'nadir'  e.g. LANDSAT MSS /TM

7. Pushbroom (along-track):
an array of diodes (one for each column of pixels) is 'pointed' in a selected direction, nadir or off-nadir, on request, usually 0-30 degrees (max.), e.g. SPOT HRV, most of them today .. (Landsat 8 OLI ?) 7

8. 3. Sensor groups
Multi-spectral sensors record bands in multiple wavelengths:
Visible
Near IR
Mid IR
Thermal
Microwave
And at different spatial resolutions (pixel size e.g….. ):
Low km
Medium m
High m
Very high m
Most satellites carry multiple sensors with different resolutions

9. Selected satellite remote sensing systems
NASA Visible Earth:   long list
Wim Bakker's website   

10. 4. Resolution - low Weather: GOES (24 HOURS per day)
GOES 8: 75W longitude, GOES 9: 135W longitude
VNIR/TIR (5 bands), Visible: 1km,
Thermal: 4km, 10-bit data (DN = ) .

11. NOAA AVHRR (Advanced ‘Very High’ Resolution Radiometer) 1
NOAA AVHRR (Advanced ‘Very High’ Resolution Radiometer) 1.1km Red / NIR / TIR 1978-present (16 satellites to 2000)- global vegetation monitoring: data are freely downloadable two run concurrently, one passing over in a.m., one in p.m x 2500 pixels, 10 bit data

12. 5. MEDIUM RESOLUTION (100m-500m)
MODIS (MODerate resolution Imaging Spectroradiometer) Descending 10.30am on Terra, Ascending 1.30pm on Aqua
Red / NIR: 250metres (2 bands) Blue/Green/NIR/MIR: 500 metres (4 bands) VNIR/MIR/TIR: 1000 metres (29 bands) Swath width: 2330km

13. Medium-high RESOLUTION 50-100m
LANDSAT (U.S.) initially known as ERTS
1972 Landsat 1 Multi-Spectral Scanner (MSS: 80m)
1975 Landsat 2 until 1982
1978 Landsat 3 until 1983

14. High resolution 5-50m Landsat 4 and 5 Thematic Mapper (TM) 1982/84: ‘the next generation’
Improved resolution (80 -> 30 m)
Addition of mid-IR (and thermal)

15. HIGH RESOLUTION – Landsat 4-7
LANDSAT (U.S.) - the next generation
1982 Landsat 4 Thematic Mapper (TM) until 1987
1984 Landsat 5 TM ... operational till Nov 2011
Landsat Enhanced TM: (ETM+) failed shortly after launch
1999 Landsat 7 ETM+  ...   sensor malfunctionned April 2003
2005 Landsat imagery (ETM-2000) was used for Google Earth mosaic
[Overlap for Landsat scenes is 14% at equator, 45% at 50 degrees ]

16. Enhanced Thematic Mapper Plus (ETM+) (Landsat 7):
Additional band versus Landsat 5 TM:
PAN (Green->IR) band 15m,
[Thermal band is 60m (versus 120m for Landsat 5]
   Sensor malfunctionned , April 2003
Landsat 7 data ( )
used for Google Earth and
Google maps mosaics

17. Landsat 8 successfully launched February 2013

18. Landsat 8 successfully launched February 2013
Operational Land Imager (OLI) TM 1 2 3 4 5 7
ETM+ 8

19. Landsat 8 successfully launched February 2013
Thermal InfraRed Sensor TIRS 6

20. Landsat 8 OLI versus Landsat 7 ETM+ bands

21. SPOT (France) High Resolution Visible (HRV) bands 1986 ->

22. Summary table: Landsat TM versus SPOT HRV (1980s)
LANDSAT TM
SPOT HRV
Launch
1982 / 1984
1986
Altitude
705 km
832 km
Attitude (polar)
8.2 degrees
8.7 degrees
Equatorial time
9.45 am
10.30 am
Swath width
185km
60km 
Repeat coverage
16 days
26 days
Sensor 
Thematic Mapper (TM)
High Resolution Visible (HRV)
Number of detectors
100
6000/3000
Advantages 
#bands, swath size
higher resolution, # 'looks'
Bands 7
(no MIR bands)
Scanner type
Mirror (Whisk broom)
Pushbroom

23. IRS (Indian Remote Sensing)
IRS 1988, 1991, 1993, …. Resourcesat / Cartosat 2011
LISS (Linear Imaging Self Scanner), 5.8m resolution in PAN
Multispectral in Visible / Near-IR at 23.5m
… and shortwave IR (SWIR) at 70m;
also Wide Field Sensor (WiFS) Red/NIR, 190m
wikipedia IRS   

24. SPOT (France) Systeme Probatoire d'Observation de la Terre
1 - 5:  
programmable, pushbroom -60km wide
SPOT 5: PAN 2.5 or 5m, 10m multispectral (G / R / Near IR / mid IR)      
SPOT receiving station at U. Lethbridge (2005)
SPOT imagery ( ) downloadable from geobase.ca
SPOT 6 (2012) and SPOT 7 (2014): 1.5 m Visible, Pan, NIR

25. Sentinel – Radar and Multispectral
European Commission (EU executive) and the European Space Agency
ESA - Sentinel

26. 7. Very high resolution 0.5- 5m (Corporate) 2000->
e.g. Ikonos, Quickbird, Worldview, Geoeye and others
Inauguration of Barack Obama as US President – Jan (Geoeye)

27. Low-tech from balloon, launched by students in Massachusetts, September 2, 2009
Total cost: (weather) balloon, camera (from eBay) and hand warmers < $130

28. UK space program: Teddies in Space
The teddy bears endured temperatures of -53C but had special spacesuits made by school children.

29. Teddies in Space: landed 50 miles away from launch pad

30. Some more links to Sensor data
Earth Explorer – We have already used this site – our most used
Glovis – Preceded EE and has a greater number of datasets
Reverb – Crazy amount of data gathered here
Sentinel (Copernicus) – clunky (Scott has set up a user and tested)