Space App Flashcards
Name the three “Space Applications” pillar
a) Earth Observation & Remote Sensing (EO/RS)
b) Position Navigation & Timing (GNSS)
c) Satellite Communication (Satcomms)
Deliver the SWOT for EO/RS
S - Availability
- Global Range
- Reliability
W - Cost (Launch, Operation)
- Low Maintainability - Space Debris/Radiation
O - Real Time Imagery
- Research - International Cooperation
T - Interference, Jamming, Spoofing
- Aircraft / Drones
Deliver the SWOT for GNSS
S - Availability & Cheap
- Accuracy
- Redundancy
W - Availability depending on weather, terrain, and
politics
- Saturation of Frequency
- Cost (Launch, Operation)
O - Autonomous logistics & Transport
- Improved ATC - Robust system against Hacking
T - Interference, Jamming, Spoofing
- Space Debris/Radiation
Deliver the SWOT for Satcomms
S - High data rate
- Flexibility
- Independent of ground events
W - High investment cost
- Low Maintainability - Latency / Delay of Signal
O - Low Competition
- Technology Improvement
T - Weather and Terrain dependency
- Space Debris/Radiation
List the autonomous GNSS Systems with their respective countries:
GPS - U.S
Galileo - E.U
GLONASS - Russia
Compass - China
Draw the diagram of Signals in Space
DRAW IT BITCH
Main Carrier Frequency for GPS / Galileo (L1, E1)
The frequency at which the GPS satellite transmits the signal. It consists of status messages and & pseudo-random noise
f = 1575.42 MHz
Describe the Five possible sources of error in GNSS position calculation
1) Ionosphere Error:
Due to signal interaction with charged particles in the atmosphere
2) Ephemeris Orbital Error:
Due to orbital perturbation which causes an error of satellite position in orbit.
3) Clock Error:
Error in atomic clocks of the satellite (minor)
4) Dilution of Precision:
When two satellites are close to each other, the accuracy of position decreases.
5) Multipath error:
Error due to the reflection of signals by buildings/terrain
Fundamental Frequency Value
Universal Frequency at which all satellites are capable of transmitting their signal.
f = 10.23 Mhz
What’s the C/A code?
Open Pseudo-random code available for civilian use. It consists of time data from the satellite atomic clock and it matches it with time data from the receiver to obtain relative timing.
What’s the PRN code?
Stands for pseudo-random noise, unique code per satellite
What’s the Navigation Message?
Low-frequency signal that gives information about the satellite orbit, ID, clock correction, etc.
DRAW the frequency diagram for L1 and L2 with the respective C/A and P-code frequency values
DRAW IT HOE
Mention each type of resolution:
1) Spectral
2) Spatial
3) Radiometric
4) Temporal
What’s Spatial resolution?
Defined by pixel size that represents the area of a surface measured in ground.
Determined by the sensor’s instantaneous field of view.
