# An Overview of Infrared Remote Sensing of Volcanic Activity
## 6 Prospects for the Future  
Sensors used for the infrared monitoring of volcanic activity have immense utility and indeed, have become essential for the monitoring of volcanoes globally. However, there remains a number of shortcomings dictated by the temporal-spatial-spectral resolution trade-off (see Figure 4). These trade-offs have significance when it comes to the remote monitoring of volcanic activity, which, itself, is greatly variable in space, time and intensity. In the case of prolonged eruptive behaviour, such as the incessant effusion of fresh lava from Kilauea, Hawaii, the relatively poor spatial resolution of MODIS, for example, is optimal for accurate and quantifiable observations as it reduces the possibility of image saturation, while its relatively high temporal resolution means that variations in the effusive activity can be well monitored through time. For an unexpected explosive eruption, however, even relatively high temporal resolution imagery (e.g., sub-daily) may be inadequate, resulting in such events often going undetected. Consequently, despite its advantages, infrared remote sensing alone cannot be relied upon for volcanic monitoring, although it constitutes an essential tool for geologists to better understand volcanic processes and for hazard managers to monitor and mitigate associated risks. [PERSON] and [PERSON] [81] argued that 2000-2010 had shown greater progress in the field of volcanic remote sensing than they envisaged for the following decade (up to 2020). Indeed, they discussed the debate that was required to ensure that the subsequent generation of Landsat sensors possessed any infrared sensing capabilities at all [50; 81]; the apparent dearth of research over recent years might be explained by several factors, such as that the NASA sensors launched in the late 1990s and early 2000s are coming to the end of their operational lives, while those that remain functional (e.g., Landsat-7 and MODIS) have less than optimal spatial or temporal resolutions. New satellites have been launched with infrared imaging capabilities, such as Landsat-8 and VIIRS on-board S-NPP, but volcanic use of these has been limited, despite showing comparability [20], or indeed improved performance [67]; some retrograde steps, such as the reduction in Landsat-8's infrared spatial resolution, have also been taken. The limited utilisation of these sensors for volcanological studies is by no means a reflection of their potential, and it remains to be seen what new and innovative volcanic observational uses will be derived. At the same time, the body of data from all sensors in orbit continues to grow, providing a repository from which more accurate and representative estimations of volcanic activity might be drawn (e.g., [66]). In the near future, the provision of infrared volcanic observations will continue, with the successor to the S-NPP, the NASA Joint Polar Satellite System (JPSS 1), due for launch in 2017 and possessing the already proven VIIRS, and with the launch of the ground-breaking Hypsiri sensor, currently planned for 2020 at the earliest [119]. This latter sensor will possess a similar contingent of VVNIR and SWIR bands as its predecessor, Hyperion (212 bands between 380 and 2500 nm, although at a reduced spatial resolution of 60 m); additionally, it will have spatially-aligned and higher resolution MIR/TIR imagers (imaging at 60 m in eight bands between 4 \(\upmu\)m and 13 \(\upmu\)m). Crucially for Hypsiri, for which one second of operation will produce up to 1 GB of data, the capacity for on-board data processing via an 'Intelligent Payload Module' (IMP) and direct broadcast of a subset of the data [26; 28; 119] are useful innovations. On-board automated analyses will have the capacity to identify specific features, for example a volcanic eruption, and once identified, this might trigger further observations of the rapidly changing surface and/or re-task other sensors to make such observations [26; 28]. [PERSON] et al.