The grades of four aerospace and defense stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

DigitalGlobe, Inc. (DGI) is bettering its rating of C (“hold”) from last week to a B (“buy”) this week. DigitalGlobe provides commercial earth imagery products and information services worldwide. In Portfolio Grader’s specific subcategory of Sales Growth, DGI also gets an A. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of DGI stock.

TASER International, Inc. (TASR) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. Taser International develops, assembles, and markets less-lethal weapons for use in the law enforcement, private security, and personal defense markets. For more information, get Portfolio Grader’s complete analysis of TASR stock.

This is a strong week for AeroVironment, Inc. (AVAV). The company’s rating climbs to B from the previous week’s C. AeroVironment designs, tests, and manufactures diversified technological products, including small, unmanned, remote-control military aircraft and rapid battery-charging stations. The stock price has risen 23.5% over the past month, better than the 1.3% decrease the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of AVAV stock.

This week, CAE Inc. (CAE) pushes up from a C to a B rating. CAE is engaged in the design, development and production of simulation tools and equipment for commercial airlines, business aircraft operators, aircraft manufacturers and military organizations. The stock has inched up 1.3% over the past week. For more information, get Portfolio Grader’s complete analysis of CAE stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.