3. Algorithms and models for a scan

摘要

This chapter describes the basic algorithms and models used for a new scan. In scheduling a scan means the time period during which a network of stations observes the same source simultaneously. This chapter focuses on the determination of various scan features, e.g. start time and scan length. A new scan will start as soon as possible, taking into account the time required for the antennas to move to the new source. A scan should begin at the same time at all stations participating in the scan as required for correlation. Each station observes for a different length of time to achieve the SNR target considering its antenna sensitivity, i.e. the scan ends at different times at all stations. Source flux densities and antenna sensitivities can be used, along with user-specified minimum SNRs, to compute scan times for each station. Furthermore, many limitations are imposed on the new scan and various conditions should be satisfied. This chapter also discusses the definition of a valid scan and introduces error conditions processing. Whether either scheduling strategy is used, all of these scan features are fully calculated. The algorithms, models and detailed equations related to a scan are explained in the next sections separately.