**3. Emergency communications network design strategy**

The design and implementation of the emergency communications network for disaster management integrated by communications satellites and remote sensing satellites and also their ground stations can be divided systematically into six (o6) main tasks: In first place, an operational procedure is formulated to maneuver the remote sensing satellites in orbit for optimal images capture in disaster events, considering the spatial and spectral resolution; then a model to images management and processing at ground segment level in emergency is designed, following which the technical characterization of the communications satellites transponders and radio frequency spectrum is carried out, with the aim to design the communications services necessaries for disasters management labors; subsequently, diverse communications applications and technology solutions are formulated, essentials for images and data exchange in disaster events, and the communications satellites transponders technical specifications to carry out the planning and design of the communications links budgets for priority services in emergency are analyzed afterward; lastly, the design of the topology and infrastructure required to integrate the communications satellites and remote sensing satellites to operate in an emergency communications network for disaster management, functional to be activated in events that affect the communications services facilities, is developed.

Nevertheless, to exemplify the emergency communications network design and describe the strategies proposed to maneuver the remote sensing satellites and communications satellites in emergency scenarios, two remote sensing satellites (Remote Sensing Satellite-1 and Remote Sensing Satellite-2) and one communications satellite (Satnet-3) were selected to integrate the network. More satellite platforms could also be integrated into the network, according to the availability thereof in disaster events. **Figure 2** describes the six tasks defined to design the emergency communications network for disaster management proposed in this chapter.

## **3.1 Operational procedure to maneuver the remote sensing satellites spatial resolution in disaster events**

The remote sensing satellites spatial resolution refers in specific to the capacity that has the sensor installed on the satellite platform to distinguish or characterize the resolving power captured, with the aim to identify and also categorize the characteristics of two or more objects observed on the area scanned. This resolving capacity is related to the instantaneous field of view (IFOV) size of the sensor and intrinsically associated with the sensor geometrical characteristics, the sensor capacity to


#### **Figure 2.**

*Emergency communications network design strategy.*

discriminate the targets tracked, the sensor capacity to calculate the periodicity of distinct targets tracked, and also to the sensor ability to determine the small targets spectral properties to obtain their spectral signatures. It is important to point out that the remote sensing spatial resolution has significant use in disaster events; its adequate application allows the sensor capturing images with details or specific characteristics required of the area tracked, affected by one or more disasters.

Especially, different spatial resolutions are necessaries that depend on the disaster occurred to ensure the images acquisition accuracy of diverse objects or of the earth surface characteristics through the sensor. In disaster management or emergency response, the spatial resolution is used principally to distinguish the diverse damages on the infrastructures affected by disasters, to establish the adequate measures for fast recovery of damages, to determine the respective scale for images analysis, and to characterize or define the location and areal precision on a surface given. In this way, to scan small areas and capture the more precise features thereof, it is necessary to use high resolution, but for wide areas, the smallest resolutions are frequently enough to recognize the features desired. On the other hand, the remote sensing satellite has a spatial coverage, an operational characteristic that defines the remote sensing satellite's geographical coverage in an interval of time; aspect that must be analyzed altogether with the sensors spatial resolution, since the different satellite land coverage variations, produced by the sensor scanning angles changes, will influence the sensor spatial resolution performance.

**Figure 3** illustrates the remote sensing satellite terrain coverage and its field of view (FOV) angle. In this respect, at the first place, the sensor field of view (FOV) angle is represented on the figure; this angle corresponds to the whole area viewed by the sensor at a specific period of time and in particular is referred to the sensor radiometric resolution ability to capture the energy from the surface scanned. Equally, the same figure shows the sensor instantaneous field of view (IFOV), which represents the smallest solid angle subtended by the sensor opening from a specific height in orbit at one interval of time during a scanning period. However, the sensor observing area size can be obtained from IFOV angle multiplied by the distance, that is, from ground to the sensor in orbit, and the result represents the ground resolution cell viewed by the sensor, specifying the maximum sensor spatial resolution on the surface scanned. Finally, the figure describes the satellite trace direction and the sensor scan trajectory on the terrain. Both the sensor spatial resolution and the pixels size have a relation between them since the pixels size are modified by the sensor sweep on the earth surface due to the curvature thereof, which is more prominent at the border of the earth's surface scanned.

**191**

*Emergency Communications Network for Disaster Management*

*Remote sensing satellite terrain coverage and field of view (FOV).*

Regarding the previous considerations, about the remote sensing satellites spatial resolution and its application in disaster management, the remote sensing satellites sensors have operational technical specifications that influence the images capturing performance. These specifications are considered during the emergency communications network design and proposed to be managed with the objective to optimize the sensors spatial resolution performance in disasters events. Such technical specifications are specified following: remote sensing sensor terrain swath coverage estimation, potential remote sensing sensor terrain swath coverage in nadir and at off-nadir angle, remote sensing sensor pixels size estimation at nadir and off-nadir angle, and remote sensing sensor dwelling time for an along track scan; strategies are useful to achieve the best remote sensing satellite platforms performance inside the

*Remote Sensing Satellite-1 and Remote Sensing Satellite-2 cameras resolution and field of view (FOV) angles.*

**Satellite Camera Resolution FOV (nadir)**

Remote Sensing Satellite-1 WMC ≤16 m 16.44°

MS: ≤10 m

MS ≤ 4 m

60 m (LWIR)

5.15°

2.93°

2.8°

Remote Sensing Satellite-1 PMC PAN: ≤2.5 m

Remote Sensing Satellite-2 HRC Pam ≤1 m

Remote Sensing Satellite-2 IRC 30 m (SWIR)

emergency communications network during the disaster management.

*3.1.1 Remote sensing sensors terrain swath coverage estimation in disaster* 

tion cameras (HRC) and infrared cameras (IRC).

*events (RSTSC*e*)*

In **Table 1**, as examples are shown, the cameras resolutions and their fields of view (FOV), for the two (02) remote sensing satellites, are proposed to be part of the emergency communications network in disasters. In this regard, the Remote Sensing Satellite-1 has PAN and multispectral cameras (PMC) and also wide swath multispectral cameras (WMC) and the Remote Sensing Satellite-2 has high-resolu-

The remote sensing satellites on orbit operation have the capacity to change the view pointing angle of their sensors through the roll maneuvers; operational strategy implemented with the aim to allow the sensors to observe in different positions in direction to the vertical trajectory view angle on the terrain; from the nadir angle,

*DOI: http://dx.doi.org/10.5772/intechopen.85872*

**Figure 3.**

**Table 1.**

#### **Figure 3.**

*Natural Hazards - Risk, Exposure, Response, and Resilience*

*Emergency communications network design strategy.*

discriminate the targets tracked, the sensor capacity to calculate the periodicity of distinct targets tracked, and also to the sensor ability to determine the small targets spectral properties to obtain their spectral signatures. It is important to point out that the remote sensing spatial resolution has significant use in disaster events; its adequate application allows the sensor capturing images with details or specific characteristics required of the area tracked, affected by one or more disasters.

Especially, different spatial resolutions are necessaries that depend on the disaster occurred to ensure the images acquisition accuracy of diverse objects or of the earth surface characteristics through the sensor. In disaster management or emergency response, the spatial resolution is used principally to distinguish the diverse damages on the infrastructures affected by disasters, to establish the adequate measures for fast recovery of damages, to determine the respective scale for images analysis, and to characterize or define the location and areal precision on a surface given. In this way, to scan small areas and capture the more precise features thereof, it is necessary to use high resolution, but for wide areas, the smallest resolutions are frequently enough to recognize the features desired. On the other hand, the remote sensing satellite has a spatial coverage, an operational characteristic that defines the remote sensing satellite's geographical coverage in an interval of time; aspect that must be analyzed altogether with the sensors spatial resolution, since the different satellite land coverage variations, produced by the sensor scanning angles changes, will influence the sensor spatial resolution performance.

**Figure 3** illustrates the remote sensing satellite terrain coverage and its field of view (FOV) angle. In this respect, at the first place, the sensor field of view (FOV) angle is represented on the figure; this angle corresponds to the whole area viewed by the sensor at a specific period of time and in particular is referred to the sensor radiometric resolution ability to capture the energy from the surface scanned. Equally, the same figure shows the sensor instantaneous field of view (IFOV), which represents the smallest solid angle subtended by the sensor opening from a specific height in orbit at one interval of time during a scanning period. However, the sensor observing area size can be obtained from IFOV angle multiplied by the distance, that is, from ground to the sensor in orbit, and the result represents the ground resolution cell viewed by the sensor, specifying the maximum sensor spatial resolution on the surface scanned. Finally, the figure describes the satellite trace direction and the sensor scan trajectory on the terrain. Both the sensor spatial resolution and the pixels size have a relation between them since the pixels size are modified by the sensor sweep on the earth surface due to the curvature thereof,

which is more prominent at the border of the earth's surface scanned.

**190**

**Figure 2.**

*Remote sensing satellite terrain coverage and field of view (FOV).*


#### **Table 1.**

*Remote Sensing Satellite-1 and Remote Sensing Satellite-2 cameras resolution and field of view (FOV) angles.*

Regarding the previous considerations, about the remote sensing satellites spatial resolution and its application in disaster management, the remote sensing satellites sensors have operational technical specifications that influence the images capturing performance. These specifications are considered during the emergency communications network design and proposed to be managed with the objective to optimize the sensors spatial resolution performance in disasters events. Such technical specifications are specified following: remote sensing sensor terrain swath coverage estimation, potential remote sensing sensor terrain swath coverage in nadir and at off-nadir angle, remote sensing sensor pixels size estimation at nadir and off-nadir angle, and remote sensing sensor dwelling time for an along track scan; strategies are useful to achieve the best remote sensing satellite platforms performance inside the emergency communications network during the disaster management.

In **Table 1**, as examples are shown, the cameras resolutions and their fields of view (FOV), for the two (02) remote sensing satellites, are proposed to be part of the emergency communications network in disasters. In this regard, the Remote Sensing Satellite-1 has PAN and multispectral cameras (PMC) and also wide swath multispectral cameras (WMC) and the Remote Sensing Satellite-2 has high-resolution cameras (HRC) and infrared cameras (IRC).
