1. Remote Sensing SPOT and Other Moderate Resolution Satellite Systems

3. SPOT
Le Systeme Pour l'Observation de la Terre (Earth Observation System)
SPOT 1, 2, 4

4. 1. SPOT 1,2,3 A French satellite system
- SPOT-1 was launched in Feb 21, 1986
- SPOT-2 in 1990
- SPOT-3 in 1993
The first commercial system designed to provide high quality service and data for operational users worldwide

5. 2. Orbits Altitude 832km Inclination 98.70
10:30am passes descending point
26 days for vertical observation, 1-4 days for oblique observations

6. 3. SPOT Sensor Systems
Components      - two identical High Resolution Visible (HRV) imaging systems – pushbroom
        - a telemetry transmitter, and magnetic tape recorders

7. 3. The Pushbroom Technique
“Pushbroom" scans based on charge coupled devices (CCD) which allows imaging the entire data line along track
A linear array of CCDs each corresponding to a pixel
 Pushbroom allows longer lifetime, reduced geometric errors, and longer dwell time                  

8. 3. Pushbroom .. A 6,000-detector subarray for the pan band
Three 3,000-detector subarrays for the three multispectral bands respectively
The pointable mirror is controlled by the ground station to acquire oblique images
   
A: Linear Array of Detectors B: Focal Plane of Image C: Lense D: Ground Resolution Cell

9. 4. SPOT Resolutions
Panchromatic mode
Multispectral mode    

10. 4. Resolutions - Pan
Panchromatic mode  - spectral resolution: microm  - radiometric resolution: 256 level of brightness  - spatial resolution: 10x10m  - temporal resolution: days

11. 4. Resolutions - XS Multispectral configuration - spectral resolution:
band1: mm (green) band2: mm (red) band3: mm (near infrared)  - radiometric resolution: 256 levels  - spatial resolution: 20x20m  - temporal resolution: days

12. 5. The Nadir Viewing
The nadir viewing
The off-nadir viewing

13. 5. The Nadir Viewing .. The total swath is 117km
The two 60km swath overlap 3km
The total swath is 117km

14. 5. The Off-Nadir Viewing..
Can view in a maximum 27o in 45 steps of 0.6o each
Can view an area of a maximum 950km, with each scene 60-80km

15. 5. The Off-Nadir Viewing ..
The same area can be viewed from different angles to acquire stereo coverage
The twin sensors can operate in different viewing angles

16. SPOT 1, 2, 3 SPOT 1 was withdrawn in 1990 SPOT 2 is deorbited in 2009
SPOT 3 stopped in 1997

17. 6. SPOT 4, 5, and 6
SPOT 4
SPOT 5
SPOT 6

18. 6. SPOT 4
Launched on Mar 23, 1998
High Resolution Visible and Infrared (HRVIR)
An additional mid-infrared mm for vegetation, mineral, and soil moisture monitoring
Replace the pan band with a red band that produces both 10m black/white and 20m XS data
A wide IFOV Vegetation Monitoring Instrument with 1km resolution, 2250km swath, B, R, NIR, MIR bands

19. 6. SPOT 5
Launched on May 3, 2002
Replace HRVIR with two high resolution geometric instruments (HRG)
A 5m pan band, 10m G, R, NIR bands, and a 20m MIR band 
High resolution stereoscopic (HRS) instrument, prepares 10m global wide DEM

20. 6. SPOT 6 Launched on September 9, 2012 Altitude 694 Km
A 1.5m pan band, 8m B, G, R, NIR bands
High resolution stereoscopic (HRS) instrument, prepares 10m global wide DEM

21. 7. SPOT Data
Direct transmission occurs within 2,600km to the ground stations, otherwise tape recorders are used
 SPOT Image Co.

22. Moderate Resolution Land Satellites
IRS (the Indian Remote Sensing)
RESURS-01 (Russia)
ADEOS (ADvanced Earth Observing Satellite, Japan)
JERS-1 (Japan)

23. 1. IRS (The Indian Remote Sensing)
 Developed, launched, and operated by the Republic of India
 IRS-1A (1988) and IRS-1B (1991)   - XS bands similar to TM bands 1-4   - spatial resolutions 72.5 m and 36.5m   km swath
 IRS-1C (1995) and IRS-1D (1997)   - XS bands 23m resolution, a MIR band 70m resolution   - a pan band 5.8m resolution   - Wide Field Sensor 188m resolution, 774km swath

24. 2. RESURS (Russia)
 The series was launched by Russia in 1985, 1988, 1994, 1998
RESURS-01 3, 4 
m, m resolution for the green, red, and 2 NIR bands   m resolution for the thermal band   km swath   - 4-day temporal resolution at the equator, daily at high latitudes  

25. 3. ADEOS (ADvanced Earth Observing Satellite, Japan)
Launched by Japan in 1996
The Advanced Visible and Near Infrared Radiometer   - B, G, R, NIR bands, 16m resolution   - a pan band 8m resolution   - 80km swath
 Ocean Color and Temperature Sensor    - 8 bands in visible and NIR, 4 bands in thermal region    - 700m resolution, 3 day temporal resolution

26. 4. JERS-1 (Japan) Developed by Japan, 1992-1998
 Optical Scanner - uses pushbroom scanning in 7 visible, NIR, and MIR bands - stereoscopic observation x24m resolution km swath  

27. 5. Other satellites launched since 2000 by many countries
China-Brazil, korea, European space agency, Algeria, Turkey, Nigeria, UK, India, Thailand, Russia, China  

28. Readings
Chapter 6